diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index e2e9319e..d44e50d3 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -1,7 +1,7 @@
 {
 	"ImportPath": "github.com/google/cadvisor",
 	"GoVersion": "go1.6",
-	"GodepVersion": "v74",
+	"GodepVersion": "v79",
 	"Packages": [
 		"./..."
 	],
@@ -466,25 +466,25 @@
 		},
 		{
 			"ImportPath": "github.com/prometheus/client_golang/prometheus",
-			"Comment": "0.7.0-52-ge51041b",
-			"Rev": "e51041b3fa41cece0dca035740ba6411905be473"
+			"Comment": "v0.8.0-62-g08fd2e1",
+			"Rev": "08fd2e12372a66e68e30523c7642e0cbc3e4fbde"
 		},
 		{
 			"ImportPath": "github.com/prometheus/client_model/go",
-			"Comment": "model-0.0.2-12-gfa8ad6f",
-			"Rev": "fa8ad6fec33561be4280a8f0514318c79d7f6cb6"
+			"Comment": "model-0.0.2-14-g6f38060",
+			"Rev": "6f3806018612930941127f2a7c6c453ba2c527d2"
 		},
 		{
 			"ImportPath": "github.com/prometheus/common/expfmt",
-			"Rev": "1cc3e4c3b28fd42633a8c389c98cfbadf42621b1"
+			"Rev": "49fee292b27bfff7f354ee0f64e1bc4850462edf"
 		},
 		{
 			"ImportPath": "github.com/prometheus/common/model",
-			"Rev": "1cc3e4c3b28fd42633a8c389c98cfbadf42621b1"
+			"Rev": "49fee292b27bfff7f354ee0f64e1bc4850462edf"
 		},
 		{
 			"ImportPath": "github.com/prometheus/procfs",
-			"Rev": "6c34ef819e19b4e16f410100ace4aa006f0e3bf8"
+			"Rev": "1e2146578273cef808354faa16a1922e0b5d6b2f"
 		},
 		{
 			"ImportPath": "github.com/seccomp/libseccomp-golang",
@@ -619,6 +619,14 @@
 			"ImportPath": "gopkg.in/olivere/elastic.v2/uritemplates",
 			"Comment": "v2.0.12",
 			"Rev": "3cfe88295d20b6299bd935131fc0fd17316405ad"
+		},
+		{
+			"ImportPath": "github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg",
+			"Rev": "49fee292b27bfff7f354ee0f64e1bc4850462edf"
+		},
+		{
+			"ImportPath": "github.com/prometheus/procfs/xfs",
+			"Rev": "1e2146578273cef808354faa16a1922e0b5d6b2f"
 		}
 	]
 }
diff --git a/vendor/github.com/prometheus/client_golang/NOTICE b/vendor/github.com/prometheus/client_golang/NOTICE
index 37e4a7d4..dd878a30 100644
--- a/vendor/github.com/prometheus/client_golang/NOTICE
+++ b/vendor/github.com/prometheus/client_golang/NOTICE
@@ -7,11 +7,6 @@ SoundCloud Ltd. (http://soundcloud.com/).
 
 The following components are included in this product:
 
-goautoneg
-http://bitbucket.org/ww/goautoneg
-Copyright 2011, Open Knowledge Foundation Ltd.
-See README.txt for license details.
-
 perks - a fork of https://github.com/bmizerany/perks
 https://github.com/beorn7/perks
 Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/README.md b/vendor/github.com/prometheus/client_golang/prometheus/README.md
index 81032bed..44986bff 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/README.md
+++ b/vendor/github.com/prometheus/client_golang/prometheus/README.md
@@ -1,53 +1 @@
-# Overview
-This is the [Prometheus](http://www.prometheus.io) telemetric
-instrumentation client [Go](http://golang.org) client library.  It
-enable authors to define process-space metrics for their servers and
-expose them through a web service interface for extraction,
-aggregation, and a whole slew of other post processing techniques.
-
-# Installing
-    $ go get github.com/prometheus/client_golang/prometheus
-
-# Example
-```go
-package main
-
-import (
-	"net/http"
-
-	"github.com/prometheus/client_golang/prometheus"
-)
-
-var (
-	indexed = prometheus.NewCounter(prometheus.CounterOpts{
-		Namespace: "my_company",
-		Subsystem: "indexer",
-		Name:      "documents_indexed",
-		Help:      "The number of documents indexed.",
-	})
-	size = prometheus.NewGauge(prometheus.GaugeOpts{
-		Namespace: "my_company",
-		Subsystem: "storage",
-		Name:      "documents_total_size_bytes",
-		Help:      "The total size of all documents in the storage.",
-	})
-)
-
-func main() {
-	http.Handle("/metrics", prometheus.Handler())
-
-	indexed.Inc()
-	size.Set(5)
-
-	http.ListenAndServe(":8080", nil)
-}
-
-func init() {
-	prometheus.MustRegister(indexed)
-	prometheus.MustRegister(size)
-}
-```
-
-# Documentation
-
-[![GoDoc](https://godoc.org/github.com/prometheus/client_golang?status.png)](https://godoc.org/github.com/prometheus/client_golang)
+See [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus).
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/collector.go b/vendor/github.com/prometheus/client_golang/prometheus/collector.go
index c0468800..623d3d83 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/collector.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/collector.go
@@ -15,15 +15,15 @@ package prometheus
 
 // Collector is the interface implemented by anything that can be used by
 // Prometheus to collect metrics. A Collector has to be registered for
-// collection. See Register, MustRegister, RegisterOrGet, and MustRegisterOrGet.
+// collection. See Registerer.Register.
 //
-// The stock metrics provided by this package (like Gauge, Counter, Summary) are
-// also Collectors (which only ever collect one metric, namely itself). An
-// implementer of Collector may, however, collect multiple metrics in a
-// coordinated fashion and/or create metrics on the fly. Examples for collectors
-// already implemented in this library are the metric vectors (i.e. collection
-// of multiple instances of the same Metric but with different label values)
-// like GaugeVec or SummaryVec, and the ExpvarCollector.
+// The stock metrics provided by this package (Gauge, Counter, Summary,
+// Histogram, Untyped) are also Collectors (which only ever collect one metric,
+// namely itself). An implementer of Collector may, however, collect multiple
+// metrics in a coordinated fashion and/or create metrics on the fly. Examples
+// for collectors already implemented in this library are the metric vectors
+// (i.e. collection of multiple instances of the same Metric but with different
+// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
 type Collector interface {
 	// Describe sends the super-set of all possible descriptors of metrics
 	// collected by this Collector to the provided channel and returns once
@@ -37,39 +37,39 @@ type Collector interface {
 	// executing this method, it must send an invalid descriptor (created
 	// with NewInvalidDesc) to signal the error to the registry.
 	Describe(chan<- *Desc)
-	// Collect is called by Prometheus when collecting metrics. The
-	// implementation sends each collected metric via the provided channel
-	// and returns once the last metric has been sent. The descriptor of
-	// each sent metric is one of those returned by Describe. Returned
-	// metrics that share the same descriptor must differ in their variable
-	// label values. This method may be called concurrently and must
-	// therefore be implemented in a concurrency safe way. Blocking occurs
-	// at the expense of total performance of rendering all registered
-	// metrics. Ideally, Collector implementations support concurrent
-	// readers.
+	// Collect is called by the Prometheus registry when collecting
+	// metrics. The implementation sends each collected metric via the
+	// provided channel and returns once the last metric has been sent. The
+	// descriptor of each sent metric is one of those returned by
+	// Describe. Returned metrics that share the same descriptor must differ
+	// in their variable label values. This method may be called
+	// concurrently and must therefore be implemented in a concurrency safe
+	// way. Blocking occurs at the expense of total performance of rendering
+	// all registered metrics. Ideally, Collector implementations support
+	// concurrent readers.
 	Collect(chan<- Metric)
 }
 
-// SelfCollector implements Collector for a single Metric so that that the
-// Metric collects itself. Add it as an anonymous field to a struct that
-// implements Metric, and call Init with the Metric itself as an argument.
-type SelfCollector struct {
+// selfCollector implements Collector for a single Metric so that the Metric
+// collects itself. Add it as an anonymous field to a struct that implements
+// Metric, and call init with the Metric itself as an argument.
+type selfCollector struct {
 	self Metric
 }
 
-// Init provides the SelfCollector with a reference to the metric it is supposed
+// init provides the selfCollector with a reference to the metric it is supposed
 // to collect. It is usually called within the factory function to create a
 // metric. See example.
-func (c *SelfCollector) Init(self Metric) {
+func (c *selfCollector) init(self Metric) {
 	c.self = self
 }
 
 // Describe implements Collector.
-func (c *SelfCollector) Describe(ch chan<- *Desc) {
+func (c *selfCollector) Describe(ch chan<- *Desc) {
 	ch <- c.self.Desc()
 }
 
 // Collect implements Collector.
-func (c *SelfCollector) Collect(ch chan<- Metric) {
+func (c *selfCollector) Collect(ch chan<- Metric) {
 	ch <- c.self
 }
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/counter.go b/vendor/github.com/prometheus/client_golang/prometheus/counter.go
index a2952d1c..72d5256a 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/counter.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/counter.go
@@ -15,7 +15,6 @@ package prometheus
 
 import (
 	"errors"
-	"hash/fnv"
 )
 
 // Counter is a Metric that represents a single numerical value that only ever
@@ -31,13 +30,8 @@ type Counter interface {
 	Metric
 	Collector
 
-	// Set is used to set the Counter to an arbitrary value. It is only used
-	// if you have to transfer a value from an external counter into this
-	// Prometheus metric. Do not use it for regular handling of a
-	// Prometheus counter (as it can be used to break the contract of
-	// monotonically increasing values).
-	Set(float64)
-	// Inc increments the counter by 1.
+	// Inc increments the counter by 1. Use Add to increment it by arbitrary
+	// non-negative values.
 	Inc()
 	// Add adds the given value to the counter. It panics if the value is <
 	// 0.
@@ -56,7 +50,7 @@ func NewCounter(opts CounterOpts) Counter {
 		opts.ConstLabels,
 	)
 	result := &counter{value: value{desc: desc, valType: CounterValue, labelPairs: desc.constLabelPairs}}
-	result.Init(result) // Init self-collection.
+	result.init(result) // Init self-collection.
 	return result
 }
 
@@ -80,7 +74,7 @@ func (c *counter) Add(v float64) {
 // CounterVec embeds MetricVec. See there for a full list of methods with
 // detailed documentation.
 type CounterVec struct {
-	MetricVec
+	*MetricVec
 }
 
 // NewCounterVec creates a new CounterVec based on the provided CounterOpts and
@@ -94,20 +88,15 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 		opts.ConstLabels,
 	)
 	return &CounterVec{
-		MetricVec: MetricVec{
-			children: map[uint64]Metric{},
-			desc:     desc,
-			hash:     fnv.New64a(),
-			newMetric: func(lvs ...string) Metric {
-				result := &counter{value: value{
-					desc:       desc,
-					valType:    CounterValue,
-					labelPairs: makeLabelPairs(desc, lvs),
-				}}
-				result.Init(result) // Init self-collection.
-				return result
-			},
-		},
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			result := &counter{value: value{
+				desc:       desc,
+				valType:    CounterValue,
+				labelPairs: makeLabelPairs(desc, lvs),
+			}}
+			result.init(result) // Init self-collection.
+			return result
+		}),
 	}
 }
 
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/desc.go b/vendor/github.com/prometheus/client_golang/prometheus/desc.go
index fcde784d..1835b16f 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/desc.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/desc.go
@@ -1,24 +1,30 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package prometheus
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
-	"hash/fnv"
-	"regexp"
 	"sort"
 	"strings"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
 
 	dto "github.com/prometheus/client_model/go"
 )
 
-var (
-	metricNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_:]*$`)
-	labelNameRE  = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
-)
-
 // reservedLabelPrefix is a prefix which is not legal in user-supplied
 // label names.
 const reservedLabelPrefix = "__"
@@ -67,7 +73,7 @@ type Desc struct {
 	// Help string. Each Desc with the same fqName must have the same
 	// dimHash.
 	dimHash uint64
-	// err is an error that occured during construction. It is reported on
+	// err is an error that occurred during construction. It is reported on
 	// registration time.
 	err error
 }
@@ -92,7 +98,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		d.err = errors.New("empty help string")
 		return d
 	}
-	if !metricNameRE.MatchString(fqName) {
+	if !model.IsValidMetricName(model.LabelValue(fqName)) {
 		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
 		return d
 	}
@@ -131,31 +137,24 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		d.err = errors.New("duplicate label names")
 		return d
 	}
-	h := fnv.New64a()
-	var b bytes.Buffer // To copy string contents into, avoiding []byte allocations.
+	vh := hashNew()
 	for _, val := range labelValues {
-		b.Reset()
-		b.WriteString(val)
-		b.WriteByte(separatorByte)
-		h.Write(b.Bytes())
+		vh = hashAdd(vh, val)
+		vh = hashAddByte(vh, separatorByte)
 	}
-	d.id = h.Sum64()
+	d.id = vh
 	// Sort labelNames so that order doesn't matter for the hash.
 	sort.Strings(labelNames)
 	// Now hash together (in this order) the help string and the sorted
 	// label names.
-	h.Reset()
-	b.Reset()
-	b.WriteString(help)
-	b.WriteByte(separatorByte)
-	h.Write(b.Bytes())
+	lh := hashNew()
+	lh = hashAdd(lh, help)
+	lh = hashAddByte(lh, separatorByte)
 	for _, labelName := range labelNames {
-		b.Reset()
-		b.WriteString(labelName)
-		b.WriteByte(separatorByte)
-		h.Write(b.Bytes())
+		lh = hashAdd(lh, labelName)
+		lh = hashAddByte(lh, separatorByte)
 	}
-	d.dimHash = h.Sum64()
+	d.dimHash = lh
 
 	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
 	for n, v := range constLabels {
@@ -196,6 +195,6 @@ func (d *Desc) String() string {
 }
 
 func checkLabelName(l string) bool {
-	return labelNameRE.MatchString(l) &&
+	return model.LabelName(l).IsValid() &&
 		!strings.HasPrefix(l, reservedLabelPrefix)
 }
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/doc.go b/vendor/github.com/prometheus/client_golang/prometheus/doc.go
index 425fe879..1fdef9ed 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/doc.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/doc.go
@@ -11,18 +11,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package prometheus provides embeddable metric primitives for servers and
-// standardized exposition of telemetry through a web services interface.
+// Package prometheus provides metrics primitives to instrument code for
+// monitoring. It also offers a registry for metrics. Sub-packages allow to
+// expose the registered metrics via HTTP (package promhttp) or push them to a
+// Pushgateway (package push).
 //
 // All exported functions and methods are safe to be used concurrently unless
 // specified otherwise.
 //
-// To expose metrics registered with the Prometheus registry, an HTTP server
-// needs to know about the Prometheus handler. The usual endpoint is "/metrics".
+// A Basic Example
 //
-//     http.Handle("/metrics", prometheus.Handler())
-//
-// As a starting point a very basic usage example:
+// As a starting point, a very basic usage example:
 //
 //    package main
 //
@@ -30,6 +29,7 @@
 //    	"net/http"
 //
 //    	"github.com/prometheus/client_golang/prometheus"
+//    	"github.com/prometheus/client_golang/prometheus/promhttp"
 //    )
 //
 //    var (
@@ -37,73 +37,149 @@
 //    		Name: "cpu_temperature_celsius",
 //    		Help: "Current temperature of the CPU.",
 //    	})
-//    	hdFailures = prometheus.NewCounter(prometheus.CounterOpts{
-//    		Name: "hd_errors_total",
-//    		Help: "Number of hard-disk errors.",
-//    	})
+//    	hdFailures = prometheus.NewCounterVec(
+//    		prometheus.CounterOpts{
+//    			Name: "hd_errors_total",
+//    			Help: "Number of hard-disk errors.",
+//    		},
+//    		[]string{"device"},
+//    	)
 //    )
 //
 //    func init() {
+//    	// Metrics have to be registered to be exposed:
 //    	prometheus.MustRegister(cpuTemp)
 //    	prometheus.MustRegister(hdFailures)
 //    }
 //
 //    func main() {
 //    	cpuTemp.Set(65.3)
-//    	hdFailures.Inc()
+//    	hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
 //
-//    	http.Handle("/metrics", prometheus.Handler())
-//    	http.ListenAndServe(":8080", nil)
+//    	// The Handler function provides a default handler to expose metrics
+//    	// via an HTTP server. "/metrics" is the usual endpoint for that.
+//    	http.Handle("/metrics", promhttp.Handler())
+//      log.Fatal(http.ListenAndServe(":8080", nil))
 //    }
 //
 //
-// This is a complete program that exports two metrics, a Gauge and a Counter.
-// It also exports some stats about the HTTP usage of the /metrics
-// endpoint. (See the Handler function for more detail.)
+// This is a complete program that exports two metrics, a Gauge and a Counter,
+// the latter with a label attached to turn it into a (one-dimensional) vector.
 //
-// Two more advanced metric types are the Summary and Histogram.
+// Metrics
 //
-// In addition to the fundamental metric types Gauge, Counter, Summary, and
-// Histogram, a very important part of the Prometheus data model is the
-// partitioning of samples along dimensions called labels, which results in
+// The number of exported identifiers in this package might appear a bit
+// overwhelming. However, in addition to the basic plumbing shown in the example
+// above, you only need to understand the different metric types and their
+// vector versions for basic usage.
+//
+// Above, you have already touched the Counter and the Gauge. There are two more
+// advanced metric types: the Summary and Histogram. A more thorough description
+// of those four metric types can be found in the Prometheus docs:
+// https://prometheus.io/docs/concepts/metric_types/
+//
+// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the
+// Prometheus server not to assume anything about its type.
+//
+// In addition to the fundamental metric types Gauge, Counter, Summary,
+// Histogram, and Untyped, a very important part of the Prometheus data model is
+// the partitioning of samples along dimensions called labels, which results in
 // metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
-// and HistogramVec.
+// HistogramVec, and UntypedVec.
 //
-// Those are all the parts needed for basic usage. Detailed documentation and
-// examples are provided below.
+// While only the fundamental metric types implement the Metric interface, both
+// the metrics and their vector versions implement the Collector interface. A
+// Collector manages the collection of a number of Metrics, but for convenience,
+// a Metric can also “collect itself”. Note that Gauge, Counter, Summary,
+// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec,
+// SummaryVec, HistogramVec, and UntypedVec are not.
 //
-// Everything else this package offers is essentially for "power users" only. A
-// few pointers to "power user features":
+// To create instances of Metrics and their vector versions, you need a suitable
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, HistogramOpts, or
+// UntypedOpts.
 //
-// All the various ...Opts structs have a ConstLabels field for labels that
-// never change their value (which is only useful under special circumstances,
-// see documentation of the Opts type).
+// Custom Collectors and constant Metrics
 //
-// The Untyped metric behaves like a Gauge, but signals the Prometheus server
-// not to assume anything about its type.
+// While you could create your own implementations of Metric, most likely you
+// will only ever implement the Collector interface on your own. At a first
+// glance, a custom Collector seems handy to bundle Metrics for common
+// registration (with the prime example of the different metric vectors above,
+// which bundle all the metrics of the same name but with different labels).
 //
-// Functions to fine-tune how the metric registry works: EnableCollectChecks,
-// PanicOnCollectError, Register, Unregister, SetMetricFamilyInjectionHook.
+// There is a more involved use case, too: If you already have metrics
+// available, created outside of the Prometheus context, you don't need the
+// interface of the various Metric types. You essentially want to mirror the
+// existing numbers into Prometheus Metrics during collection. An own
+// implementation of the Collector interface is perfect for that. You can create
+// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
+// NewConstSummary (and their respective Must… versions). That will happen in
+// the Collect method. The Describe method has to return separate Desc
+// instances, representative of the “throw-away” metrics to be created later.
+// NewDesc comes in handy to create those Desc instances.
 //
-// For custom metric collection, there are two entry points: Custom Metric
-// implementations and custom Collector implementations. A Metric is the
-// fundamental unit in the Prometheus data model: a sample at a point in time
-// together with its meta-data (like its fully-qualified name and any number of
-// pairs of label name and label value) that knows how to marshal itself into a
-// data transfer object (aka DTO, implemented as a protocol buffer). A Collector
-// gets registered with the Prometheus registry and manages the collection of
-// one or more Metrics. Many parts of this package are building blocks for
-// Metrics and Collectors. Desc is the metric descriptor, actually used by all
-// metrics under the hood, and by Collectors to describe the Metrics to be
-// collected, but only to be dealt with by users if they implement their own
-// Metrics or Collectors. To create a Desc, the BuildFQName function will come
-// in handy. Other useful components for Metric and Collector implementation
-// include: LabelPairSorter to sort the DTO version of label pairs,
-// NewConstMetric and MustNewConstMetric to create "throw away" Metrics at
-// collection time, MetricVec to bundle custom Metrics into a metric vector
-// Collector, SelfCollector to make a custom Metric collect itself.
+// The Collector example illustrates the use case. You can also look at the
+// source code of the processCollector (mirroring process metrics), the
+// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
+// metrics) as examples that are used in this package itself.
 //
-// A good example for a custom Collector is the ExpVarCollector included in this
-// package, which exports variables exported via the "expvar" package as
-// Prometheus metrics.
+// If you just need to call a function to get a single float value to collect as
+// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
+// shortcuts.
+//
+// Advanced Uses of the Registry
+//
+// While MustRegister is the by far most common way of registering a Collector,
+// sometimes you might want to handle the errors the registration might cause.
+// As suggested by the name, MustRegister panics if an error occurs. With the
+// Register function, the error is returned and can be handled.
+//
+// An error is returned if the registered Collector is incompatible or
+// inconsistent with already registered metrics. The registry aims for
+// consistency of the collected metrics according to the Prometheus data model.
+// Inconsistencies are ideally detected at registration time, not at collect
+// time. The former will usually be detected at start-up time of a program,
+// while the latter will only happen at scrape time, possibly not even on the
+// first scrape if the inconsistency only becomes relevant later. That is the
+// main reason why a Collector and a Metric have to describe themselves to the
+// registry.
+//
+// So far, everything we did operated on the so-called default registry, as it
+// can be found in the global DefaultRegistry variable. With NewRegistry, you
+// can create a custom registry, or you can even implement the Registerer or
+// Gatherer interfaces yourself. The methods Register and Unregister work in the
+// same way on a custom registry as the global functions Register and Unregister
+// on the default registry.
+//
+// There are a number of uses for custom registries: You can use registries with
+// special properties, see NewPedanticRegistry. You can avoid global state, as
+// it is imposed by the DefaultRegistry. You can use multiple registries at the
+// same time to expose different metrics in different ways. You can use separate
+// registries for testing purposes.
+//
+// Also note that the DefaultRegistry comes registered with a Collector for Go
+// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
+// NewProcessCollector). With a custom registry, you are in control and decide
+// yourself about the Collectors to register.
+//
+// HTTP Exposition
+//
+// The Registry implements the Gatherer interface. The caller of the Gather
+// method can then expose the gathered metrics in some way. Usually, the metrics
+// are served via HTTP on the /metrics endpoint. That's happening in the example
+// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
+// (The top-level functions in the prometheus package are deprecated.)
+//
+// Pushing to the Pushgateway
+//
+// Function for pushing to the Pushgateway can be found in the push sub-package.
+//
+// Graphite Bridge
+//
+// Functions and examples to push metrics from a Gatherer to Graphite can be
+// found in the graphite sub-package.
+//
+// Other Means of Exposition
+//
+// More ways of exposing metrics can easily be added by following the approaches
+// of the existing implementations.
 package prometheus
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/expvar.go b/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go
similarity index 81%
rename from vendor/github.com/prometheus/client_golang/prometheus/expvar.go
rename to vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go
index 0f7630d5..18a99d5f 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/expvar.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go
@@ -18,21 +18,21 @@ import (
 	"expvar"
 )
 
-// ExpvarCollector collects metrics from the expvar interface. It provides a
-// quick way to expose numeric values that are already exported via expvar as
-// Prometheus metrics. Note that the data models of expvar and Prometheus are
-// fundamentally different, and that the ExpvarCollector is inherently
-// slow. Thus, the ExpvarCollector is probably great for experiments and
-// prototying, but you should seriously consider a more direct implementation of
-// Prometheus metrics for monitoring production systems.
-//
-// Use NewExpvarCollector to create new instances.
-type ExpvarCollector struct {
+type expvarCollector struct {
 	exports map[string]*Desc
 }
 
-// NewExpvarCollector returns a newly allocated ExpvarCollector that still has
-// to be registered with the Prometheus registry.
+// NewExpvarCollector returns a newly allocated expvar Collector that still has
+// to be registered with a Prometheus registry.
+//
+// An expvar Collector collects metrics from the expvar interface. It provides a
+// quick way to expose numeric values that are already exported via expvar as
+// Prometheus metrics. Note that the data models of expvar and Prometheus are
+// fundamentally different, and that the expvar Collector is inherently slower
+// than native Prometheus metrics. Thus, the expvar Collector is probably great
+// for experiments and prototying, but you should seriously consider a more
+// direct implementation of Prometheus metrics for monitoring production
+// systems.
 //
 // The exports map has the following meaning:
 //
@@ -59,21 +59,21 @@ type ExpvarCollector struct {
 // sample values.
 //
 // Anything that does not fit into the scheme above is silently ignored.
-func NewExpvarCollector(exports map[string]*Desc) *ExpvarCollector {
-	return &ExpvarCollector{
+func NewExpvarCollector(exports map[string]*Desc) Collector {
+	return &expvarCollector{
 		exports: exports,
 	}
 }
 
 // Describe implements Collector.
-func (e *ExpvarCollector) Describe(ch chan<- *Desc) {
+func (e *expvarCollector) Describe(ch chan<- *Desc) {
 	for _, desc := range e.exports {
 		ch <- desc
 	}
 }
 
 // Collect implements Collector.
-func (e *ExpvarCollector) Collect(ch chan<- Metric) {
+func (e *expvarCollector) Collect(ch chan<- Metric) {
 	for name, desc := range e.exports {
 		var m Metric
 		expVar := expvar.Get(name)
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/fnv.go b/vendor/github.com/prometheus/client_golang/prometheus/fnv.go
new file mode 100644
index 00000000..e3b67df8
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/fnv.go
@@ -0,0 +1,29 @@
+package prometheus
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/gauge.go b/vendor/github.com/prometheus/client_golang/prometheus/gauge.go
index ba8a402c..9ab5a3d6 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/gauge.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/gauge.go
@@ -13,8 +13,6 @@
 
 package prometheus
 
-import "hash/fnv"
-
 // Gauge is a Metric that represents a single numerical value that can
 // arbitrarily go up and down.
 //
@@ -29,16 +27,21 @@ type Gauge interface {
 
 	// Set sets the Gauge to an arbitrary value.
 	Set(float64)
-	// Inc increments the Gauge by 1.
+	// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
+	// values.
 	Inc()
-	// Dec decrements the Gauge by 1.
+	// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
+	// values.
 	Dec()
-	// Add adds the given value to the Gauge. (The value can be
-	// negative, resulting in a decrease of the Gauge.)
+	// Add adds the given value to the Gauge. (The value can be negative,
+	// resulting in a decrease of the Gauge.)
 	Add(float64)
 	// Sub subtracts the given value from the Gauge. (The value can be
 	// negative, resulting in an increase of the Gauge.)
 	Sub(float64)
+
+	// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
+	SetToCurrentTime()
 }
 
 // GaugeOpts is an alias for Opts. See there for doc comments.
@@ -60,7 +63,7 @@ func NewGauge(opts GaugeOpts) Gauge {
 // (e.g. number of operations queued, partitioned by user and operation
 // type). Create instances with NewGaugeVec.
 type GaugeVec struct {
-	MetricVec
+	*MetricVec
 }
 
 // NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
@@ -74,14 +77,9 @@ func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
 		opts.ConstLabels,
 	)
 	return &GaugeVec{
-		MetricVec: MetricVec{
-			children: map[uint64]Metric{},
-			desc:     desc,
-			hash:     fnv.New64a(),
-			newMetric: func(lvs ...string) Metric {
-				return newValue(desc, GaugeValue, 0, lvs...)
-			},
-		},
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newValue(desc, GaugeValue, 0, lvs...)
+		}),
 	}
 }
 
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
index 8be24769..f9676455 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
@@ -8,8 +8,9 @@ import (
 )
 
 type goCollector struct {
-	goroutines Gauge
-	gcDesc     *Desc
+	goroutinesDesc *Desc
+	threadsDesc    *Desc
+	gcDesc         *Desc
 
 	// metrics to describe and collect
 	metrics memStatsMetrics
@@ -17,13 +18,16 @@ type goCollector struct {
 
 // NewGoCollector returns a collector which exports metrics about the current
 // go process.
-func NewGoCollector() *goCollector {
+func NewGoCollector() Collector {
 	return &goCollector{
-		goroutines: NewGauge(GaugeOpts{
-			Namespace: "go",
-			Name:      "goroutines",
-			Help:      "Number of goroutines that currently exist.",
-		}),
+		goroutinesDesc: NewDesc(
+			"go_goroutines",
+			"Number of goroutines that currently exist.",
+			nil, nil),
+		threadsDesc: NewDesc(
+			"go_threads",
+			"Number of OS threads created",
+			nil, nil),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
 			"A summary of the GC invocation durations.",
@@ -48,7 +52,7 @@ func NewGoCollector() *goCollector {
 			}, {
 				desc: NewDesc(
 					memstatNamespace("sys_bytes"),
-					"Number of bytes obtained by system. Sum of all system allocations.",
+					"Number of bytes obtained from system.",
 					nil, nil,
 				),
 				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
@@ -111,12 +115,12 @@ func NewGoCollector() *goCollector {
 				valType: GaugeValue,
 			}, {
 				desc: NewDesc(
-					memstatNamespace("heap_released_bytes_total"),
-					"Total number of heap bytes released to OS.",
+					memstatNamespace("heap_released_bytes"),
+					"Number of heap bytes released to OS.",
 					nil, nil,
 				),
 				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
-				valType: CounterValue,
+				valType: GaugeValue,
 			}, {
 				desc: NewDesc(
 					memstatNamespace("heap_objects"),
@@ -211,7 +215,15 @@ func NewGoCollector() *goCollector {
 					"Number of seconds since 1970 of last garbage collection.",
 					nil, nil,
 				),
-				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.LastGC*10 ^ 9) },
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("gc_cpu_fraction"),
+					"The fraction of this program's available CPU time used by the GC since the program started.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
 				valType: GaugeValue,
 			},
 		},
@@ -224,9 +236,9 @@ func memstatNamespace(s string) string {
 
 // Describe returns all descriptions of the collector.
 func (c *goCollector) Describe(ch chan<- *Desc) {
-	ch <- c.goroutines.Desc()
+	ch <- c.goroutinesDesc
+	ch <- c.threadsDesc
 	ch <- c.gcDesc
-
 	for _, i := range c.metrics {
 		ch <- i.desc
 	}
@@ -234,8 +246,9 @@ func (c *goCollector) Describe(ch chan<- *Desc) {
 
 // Collect returns the current state of all metrics of the collector.
 func (c *goCollector) Collect(ch chan<- Metric) {
-	c.goroutines.Set(float64(runtime.NumGoroutine()))
-	ch <- c.goroutines
+	ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
+	n, _ := runtime.ThreadCreateProfile(nil)
+	ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
 
 	var stats debug.GCStats
 	stats.PauseQuantiles = make([]time.Duration, 5)
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/histogram.go b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go
index f98a41bc..9719e8fa 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/histogram.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go
@@ -15,7 +15,6 @@ package prometheus
 
 import (
 	"fmt"
-	"hash/fnv"
 	"math"
 	"sort"
 	"sync/atomic"
@@ -52,11 +51,11 @@ type Histogram interface {
 // bucket of a histogram ("le" -> "less or equal").
 const bucketLabel = "le"
 
+// DefBuckets are the default Histogram buckets. The default buckets are
+// tailored to broadly measure the response time (in seconds) of a network
+// service. Most likely, however, you will be required to define buckets
+// customized to your use case.
 var (
-	// DefBuckets are the default Histogram buckets. The default buckets are
-	// tailored to broadly measure the response time (in seconds) of a
-	// network service. Most likely, however, you will be required to define
-	// buckets customized to your use case.
 	DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
 
 	errBucketLabelNotAllowed = fmt.Errorf(
@@ -211,7 +210,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 	// Finally we know the final length of h.upperBounds and can make counts.
 	h.counts = make([]uint64, len(h.upperBounds))
 
-	h.Init(h) // Init self-collection.
+	h.init(h) // Init self-collection.
 	return h
 }
 
@@ -223,7 +222,7 @@ type histogram struct {
 	sumBits uint64
 	count   uint64
 
-	SelfCollector
+	selfCollector
 	// Note that there is no mutex required.
 
 	desc *Desc
@@ -288,7 +287,7 @@ func (h *histogram) Write(out *dto.Metric) error {
 // (e.g. HTTP request latencies, partitioned by status code and method). Create
 // instances with NewHistogramVec.
 type HistogramVec struct {
-	MetricVec
+	*MetricVec
 }
 
 // NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
@@ -302,14 +301,9 @@ func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
 		opts.ConstLabels,
 	)
 	return &HistogramVec{
-		MetricVec: MetricVec{
-			children: map[uint64]Metric{},
-			desc:     desc,
-			hash:     fnv.New64a(),
-			newMetric: func(lvs ...string) Metric {
-				return newHistogram(desc, opts, lvs...)
-			},
-		},
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newHistogram(desc, opts, lvs...)
+		}),
 	}
 }
 
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/http.go b/vendor/github.com/prometheus/client_golang/prometheus/http.go
index eabe6024..d74fb488 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/http.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/http.go
@@ -15,14 +15,114 @@ package prometheus
 
 import (
 	"bufio"
+	"bytes"
+	"compress/gzip"
+	"fmt"
 	"io"
 	"net"
 	"net/http"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
+
+	"github.com/prometheus/common/expfmt"
 )
 
+// TODO(beorn7): Remove this whole file. It is a partial mirror of
+// promhttp/http.go (to avoid circular import chains) where everything HTTP
+// related should live. The functions here are just for avoiding
+// breakage. Everything is deprecated.
+
+const (
+	contentTypeHeader     = "Content-Type"
+	contentLengthHeader   = "Content-Length"
+	contentEncodingHeader = "Content-Encoding"
+	acceptEncodingHeader  = "Accept-Encoding"
+)
+
+var bufPool sync.Pool
+
+func getBuf() *bytes.Buffer {
+	buf := bufPool.Get()
+	if buf == nil {
+		return &bytes.Buffer{}
+	}
+	return buf.(*bytes.Buffer)
+}
+
+func giveBuf(buf *bytes.Buffer) {
+	buf.Reset()
+	bufPool.Put(buf)
+}
+
+// Handler returns an HTTP handler for the DefaultGatherer. It is
+// already instrumented with InstrumentHandler (using "prometheus" as handler
+// name).
+//
+// Deprecated: Please note the issues described in the doc comment of
+// InstrumentHandler. You might want to consider using promhttp.Handler instead
+// (which is not instrumented).
+func Handler() http.Handler {
+	return InstrumentHandler("prometheus", UninstrumentedHandler())
+}
+
+// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
+//
+// Deprecated: Use promhttp.Handler instead. See there for further documentation.
+func UninstrumentedHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		mfs, err := DefaultGatherer.Gather()
+		if err != nil {
+			http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		contentType := expfmt.Negotiate(req.Header)
+		buf := getBuf()
+		defer giveBuf(buf)
+		writer, encoding := decorateWriter(req, buf)
+		enc := expfmt.NewEncoder(writer, contentType)
+		var lastErr error
+		for _, mf := range mfs {
+			if err := enc.Encode(mf); err != nil {
+				lastErr = err
+				http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
+				return
+			}
+		}
+		if closer, ok := writer.(io.Closer); ok {
+			closer.Close()
+		}
+		if lastErr != nil && buf.Len() == 0 {
+			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		header := w.Header()
+		header.Set(contentTypeHeader, string(contentType))
+		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
+		if encoding != "" {
+			header.Set(contentEncodingHeader, encoding)
+		}
+		w.Write(buf.Bytes())
+	})
+}
+
+// decorateWriter wraps a writer to handle gzip compression if requested.  It
+// returns the decorated writer and the appropriate "Content-Encoding" header
+// (which is empty if no compression is enabled).
+func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
+	header := request.Header.Get(acceptEncodingHeader)
+	parts := strings.Split(header, ",")
+	for _, part := range parts {
+		part := strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return gzip.NewWriter(writer), "gzip"
+		}
+	}
+	return writer, ""
+}
+
 var instLabels = []string{"method", "code"}
 
 type nower interface {
@@ -57,29 +157,55 @@ func nowSeries(t ...time.Time) nower {
 // has a constant label named "handler" with the provided handlerName as
 // value. http_requests_total is a metric vector partitioned by HTTP method
 // (label name "method") and HTTP status code (label name "code").
+//
+// Deprecated: InstrumentHandler has several issues:
+//
+// - It uses Summaries rather than Histograms. Summaries are not useful if
+// aggregation across multiple instances is required.
+//
+// - It uses microseconds as unit, which is deprecated and should be replaced by
+// seconds.
+//
+// - The size of the request is calculated in a separate goroutine. Since this
+// calculator requires access to the request header, it creates a race with
+// any writes to the header performed during request handling.
+// httputil.ReverseProxy is a prominent example for a handler
+// performing such writes.
+//
+// - It has additional issues with HTTP/2, cf.
+// https://github.com/prometheus/client_golang/issues/272.
+//
+// Upcoming versions of this package will provide ways of instrumenting HTTP
+// handlers that are more flexible and have fewer issues. Please prefer direct
+// instrumentation in the meantime.
 func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
 	return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
 }
 
 // InstrumentHandlerFunc wraps the given function for instrumentation. It
-// otherwise works in the same way as InstrumentHandler.
+// otherwise works in the same way as InstrumentHandler (and shares the same
+// issues).
+//
+// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
+// InstrumentHandler is.
 func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
 	return InstrumentHandlerFuncWithOpts(
 		SummaryOpts{
 			Subsystem:   "http",
 			ConstLabels: Labels{"handler": handlerName},
+			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		},
 		handlerFunc,
 	)
 }
 
-// InstrumentHandlerWithOpts works like InstrumentHandler but provides more
-// flexibility (at the cost of a more complex call syntax). As
-// InstrumentHandler, this function registers four metric collectors, but it
-// uses the provided SummaryOpts to create them. However, the fields "Name" and
-// "Help" in the SummaryOpts are ignored. "Name" is replaced by
-// "requests_total", "request_duration_microseconds", "request_size_bytes", and
-// "response_size_bytes", respectively. "Help" is replaced by an appropriate
+// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
+// issues) but provides more flexibility (at the cost of a more complex call
+// syntax). As InstrumentHandler, this function registers four metric
+// collectors, but it uses the provided SummaryOpts to create them. However, the
+// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
+// by "requests_total", "request_duration_microseconds", "request_size_bytes",
+// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
 // help string. The names of the variable labels of the http_requests_total
 // CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
 //
@@ -98,13 +224,20 @@ func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWri
 // cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
 // and all its fields are set to the equally named fields in the provided
 // SummaryOpts.
+//
+// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
+// InstrumentHandler is.
 func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
 	return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
 }
 
-// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc but provides
-// more flexibility (at the cost of a more complex call syntax). See
-// InstrumentHandlerWithOpts for details how the provided SummaryOpts are used.
+// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
+// the same issues) but provides more flexibility (at the cost of a more complex
+// call syntax). See InstrumentHandlerWithOpts for details how the provided
+// SummaryOpts are used.
+//
+// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
+// as InstrumentHandler is.
 func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
 	reqCnt := NewCounterVec(
 		CounterOpts{
@@ -116,34 +249,52 @@ func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.Respo
 		},
 		instLabels,
 	)
+	if err := Register(reqCnt); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqCnt = are.ExistingCollector.(*CounterVec)
+		} else {
+			panic(err)
+		}
+	}
 
 	opts.Name = "request_duration_microseconds"
 	opts.Help = "The HTTP request latencies in microseconds."
 	reqDur := NewSummary(opts)
+	if err := Register(reqDur); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqDur = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
 
 	opts.Name = "request_size_bytes"
 	opts.Help = "The HTTP request sizes in bytes."
 	reqSz := NewSummary(opts)
+	if err := Register(reqSz); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqSz = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
 
 	opts.Name = "response_size_bytes"
 	opts.Help = "The HTTP response sizes in bytes."
 	resSz := NewSummary(opts)
-
-	regReqCnt := MustRegisterOrGet(reqCnt).(*CounterVec)
-	regReqDur := MustRegisterOrGet(reqDur).(Summary)
-	regReqSz := MustRegisterOrGet(reqSz).(Summary)
-	regResSz := MustRegisterOrGet(resSz).(Summary)
+	if err := Register(resSz); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			resSz = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		now := time.Now()
 
 		delegate := &responseWriterDelegator{ResponseWriter: w}
-		out := make(chan int)
-		urlLen := 0
-		if r.URL != nil {
-			urlLen = len(r.URL.String())
-		}
-		go computeApproximateRequestSize(r, out, urlLen)
+		out := computeApproximateRequestSize(r)
 
 		_, cn := w.(http.CloseNotifier)
 		_, fl := w.(http.Flusher)
@@ -161,30 +312,44 @@ func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.Respo
 
 		method := sanitizeMethod(r.Method)
 		code := sanitizeCode(delegate.status)
-		regReqCnt.WithLabelValues(method, code).Inc()
-		regReqDur.Observe(elapsed)
-		regResSz.Observe(float64(delegate.written))
-		regReqSz.Observe(float64(<-out))
+		reqCnt.WithLabelValues(method, code).Inc()
+		reqDur.Observe(elapsed)
+		resSz.Observe(float64(delegate.written))
+		reqSz.Observe(float64(<-out))
 	})
 }
 
-func computeApproximateRequestSize(r *http.Request, out chan int, s int) {
-	s += len(r.Method)
-	s += len(r.Proto)
-	for name, values := range r.Header {
-		s += len(name)
-		for _, value := range values {
-			s += len(value)
+func computeApproximateRequestSize(r *http.Request) <-chan int {
+	// Get URL length in current go routine for avoiding a race condition.
+	// HandlerFunc that runs in parallel may modify the URL.
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	out := make(chan int, 1)
+
+	go func() {
+		s += len(r.Method)
+		s += len(r.Proto)
+		for name, values := range r.Header {
+			s += len(name)
+			for _, value := range values {
+				s += len(value)
+			}
 		}
-	}
-	s += len(r.Host)
+		s += len(r.Host)
 
-	// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+		// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
 
-	if r.ContentLength != -1 {
-		s += int(r.ContentLength)
-	}
-	out <- s
+		if r.ContentLength != -1 {
+			s += int(r.ContentLength)
+		}
+		out <- s
+		close(out)
+	}()
+
+	return out
 }
 
 type responseWriterDelegator struct {
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/metric.go b/vendor/github.com/prometheus/client_golang/prometheus/metric.go
index 86fd81c1..d4063d98 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/metric.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/metric.go
@@ -22,10 +22,8 @@ import (
 const separatorByte byte = 255
 
 // A Metric models a single sample value with its meta data being exported to
-// Prometheus. Implementers of Metric in this package inclued Gauge, Counter,
-// Untyped, and Summary. Users can implement their own Metric types, but that
-// should be rarely needed. See the example for SelfCollector, which is also an
-// example for a user-implemented Metric.
+// Prometheus. Implementations of Metric in this package are Gauge, Counter,
+// Histogram, Summary, and Untyped.
 type Metric interface {
 	// Desc returns the descriptor for the Metric. This method idempotently
 	// returns the same descriptor throughout the lifetime of the
@@ -36,21 +34,23 @@ type Metric interface {
 	// Write encodes the Metric into a "Metric" Protocol Buffer data
 	// transmission object.
 	//
-	// Implementers of custom Metric types must observe concurrency safety
-	// as reads of this metric may occur at any time, and any blocking
-	// occurs at the expense of total performance of rendering all
-	// registered metrics. Ideally Metric implementations should support
-	// concurrent readers.
+	// Metric implementations must observe concurrency safety as reads of
+	// this metric may occur at any time, and any blocking occurs at the
+	// expense of total performance of rendering all registered
+	// metrics. Ideally, Metric implementations should support concurrent
+	// readers.
 	//
-	// The Prometheus client library attempts to minimize memory allocations
-	// and will provide a pre-existing reset dto.Metric pointer. Prometheus
-	// may recycle the dto.Metric proto message, so Metric implementations
-	// should just populate the provided dto.Metric and then should not keep
-	// any reference to it.
-	//
-	// While populating dto.Metric, labels must be sorted lexicographically.
-	// (Implementers may find LabelPairSorter useful for that.)
+	// While populating dto.Metric, it is the responsibility of the
+	// implementation to ensure validity of the Metric protobuf (like valid
+	// UTF-8 strings or syntactically valid metric and label names). It is
+	// recommended to sort labels lexicographically. (Implementers may find
+	// LabelPairSorter useful for that.) Callers of Write should still make
+	// sure of sorting if they depend on it.
 	Write(*dto.Metric) error
+	// TODO(beorn7): The original rationale of passing in a pre-allocated
+	// dto.Metric protobuf to save allocations has disappeared. The
+	// signature of this method should be changed to "Write() (*dto.Metric,
+	// error)".
 }
 
 // Opts bundles the options for creating most Metric types. Each metric
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go
index d8cf0eda..94b2553e 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go
@@ -19,16 +19,16 @@ type processCollector struct {
 	pid             int
 	collectFn       func(chan<- Metric)
 	pidFn           func() (int, error)
-	cpuTotal        Counter
-	openFDs, maxFDs Gauge
-	vsize, rss      Gauge
-	startTime       Gauge
+	cpuTotal        *Desc
+	openFDs, maxFDs *Desc
+	vsize, rss      *Desc
+	startTime       *Desc
 }
 
 // NewProcessCollector returns a collector which exports the current state of
 // process metrics including cpu, memory and file descriptor usage as well as
 // the process start time for the given process id under the given namespace.
-func NewProcessCollector(pid int, namespace string) *processCollector {
+func NewProcessCollector(pid int, namespace string) Collector {
 	return NewProcessCollectorPIDFn(
 		func() (int, error) { return pid, nil },
 		namespace,
@@ -43,41 +43,46 @@ func NewProcessCollector(pid int, namespace string) *processCollector {
 func NewProcessCollectorPIDFn(
 	pidFn func() (int, error),
 	namespace string,
-) *processCollector {
+) Collector {
+	ns := ""
+	if len(namespace) > 0 {
+		ns = namespace + "_"
+	}
+
 	c := processCollector{
 		pidFn:     pidFn,
 		collectFn: func(chan<- Metric) {},
 
-		cpuTotal: NewCounter(CounterOpts{
-			Namespace: namespace,
-			Name:      "process_cpu_seconds_total",
-			Help:      "Total user and system CPU time spent in seconds.",
-		}),
-		openFDs: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_open_fds",
-			Help:      "Number of open file descriptors.",
-		}),
-		maxFDs: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_max_fds",
-			Help:      "Maximum number of open file descriptors.",
-		}),
-		vsize: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_virtual_memory_bytes",
-			Help:      "Virtual memory size in bytes.",
-		}),
-		rss: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_resident_memory_bytes",
-			Help:      "Resident memory size in bytes.",
-		}),
-		startTime: NewGauge(GaugeOpts{
-			Namespace: namespace,
-			Name:      "process_start_time_seconds",
-			Help:      "Start time of the process since unix epoch in seconds.",
-		}),
+		cpuTotal: NewDesc(
+			ns+"process_cpu_seconds_total",
+			"Total user and system CPU time spent in seconds.",
+			nil, nil,
+		),
+		openFDs: NewDesc(
+			ns+"process_open_fds",
+			"Number of open file descriptors.",
+			nil, nil,
+		),
+		maxFDs: NewDesc(
+			ns+"process_max_fds",
+			"Maximum number of open file descriptors.",
+			nil, nil,
+		),
+		vsize: NewDesc(
+			ns+"process_virtual_memory_bytes",
+			"Virtual memory size in bytes.",
+			nil, nil,
+		),
+		rss: NewDesc(
+			ns+"process_resident_memory_bytes",
+			"Resident memory size in bytes.",
+			nil, nil,
+		),
+		startTime: NewDesc(
+			ns+"process_start_time_seconds",
+			"Start time of the process since unix epoch in seconds.",
+			nil, nil,
+		),
 	}
 
 	// Set up process metric collection if supported by the runtime.
@@ -90,12 +95,12 @@ func NewProcessCollectorPIDFn(
 
 // Describe returns all descriptions of the collector.
 func (c *processCollector) Describe(ch chan<- *Desc) {
-	ch <- c.cpuTotal.Desc()
-	ch <- c.openFDs.Desc()
-	ch <- c.maxFDs.Desc()
-	ch <- c.vsize.Desc()
-	ch <- c.rss.Desc()
-	ch <- c.startTime.Desc()
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.rss
+	ch <- c.startTime
 }
 
 // Collect returns the current state of all metrics of the collector.
@@ -117,26 +122,19 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 	}
 
 	if stat, err := p.NewStat(); err == nil {
-		c.cpuTotal.Set(stat.CPUTime())
-		ch <- c.cpuTotal
-		c.vsize.Set(float64(stat.VirtualMemory()))
-		ch <- c.vsize
-		c.rss.Set(float64(stat.ResidentMemory()))
-		ch <- c.rss
-
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
 		if startTime, err := stat.StartTime(); err == nil {
-			c.startTime.Set(startTime)
-			ch <- c.startTime
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
 		}
 	}
 
 	if fds, err := p.FileDescriptorsLen(); err == nil {
-		c.openFDs.Set(float64(fds))
-		ch <- c.openFDs
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
 	}
 
 	if limits, err := p.NewLimits(); err == nil {
-		c.maxFDs.Set(float64(limits.OpenFiles))
-		ch <- c.maxFDs
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
 	}
 }
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/push.go b/vendor/github.com/prometheus/client_golang/prometheus/push.go
deleted file mode 100644
index 1c33848a..00000000
--- a/vendor/github.com/prometheus/client_golang/prometheus/push.go
+++ /dev/null
@@ -1,65 +0,0 @@
-// Copyright 2015 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Copyright (c) 2013, The Prometheus Authors
-// All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be found
-// in the LICENSE file.
-
-package prometheus
-
-// Push triggers a metric collection by the default registry and pushes all
-// collected metrics to the Pushgateway specified by addr. See the Pushgateway
-// documentation for detailed implications of the job and instance
-// parameter. instance can be left empty. You can use just host:port or ip:port
-// as url, in which case 'http://' is added automatically. You can also include
-// the schema in the URL. However, do not include the '/metrics/jobs/...' part.
-//
-// Note that all previously pushed metrics with the same job and instance will
-// be replaced with the metrics pushed by this call. (It uses HTTP method 'PUT'
-// to push to the Pushgateway.)
-func Push(job, instance, url string) error {
-	return defRegistry.Push(job, instance, url, "PUT")
-}
-
-// PushAdd works like Push, but only previously pushed metrics with the same
-// name (and the same job and instance) will be replaced. (It uses HTTP method
-// 'POST' to push to the Pushgateway.)
-func PushAdd(job, instance, url string) error {
-	return defRegistry.Push(job, instance, url, "POST")
-}
-
-// PushCollectors works like Push, but it does not collect from the default
-// registry. Instead, it collects from the provided collectors. It is a
-// convenient way to push only a few metrics.
-func PushCollectors(job, instance, url string, collectors ...Collector) error {
-	return pushCollectors(job, instance, url, "PUT", collectors...)
-}
-
-// PushAddCollectors works like PushAdd, but it does not collect from the
-// default registry. Instead, it collects from the provided collectors. It is a
-// convenient way to push only a few metrics.
-func PushAddCollectors(job, instance, url string, collectors ...Collector) error {
-	return pushCollectors(job, instance, url, "POST", collectors...)
-}
-
-func pushCollectors(job, instance, url, method string, collectors ...Collector) error {
-	r := newRegistry()
-	for _, collector := range collectors {
-		if _, err := r.Register(collector); err != nil {
-			return err
-		}
-	}
-	return r.Push(job, instance, url, method)
-}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/registry.go b/vendor/github.com/prometheus/client_golang/prometheus/registry.go
index 5970aaee..8c6b5bd8 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/registry.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/registry.go
@@ -11,228 +11,244 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Copyright (c) 2013, The Prometheus Authors
-// All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be found
-// in the LICENSE file.
-
 package prometheus
 
 import (
 	"bytes"
-	"compress/gzip"
 	"errors"
 	"fmt"
-	"hash/fnv"
-	"io"
-	"net/http"
-	"net/url"
 	"os"
 	"sort"
-	"strings"
 	"sync"
 
 	"github.com/golang/protobuf/proto"
-	"github.com/prometheus/common/expfmt"
 
 	dto "github.com/prometheus/client_model/go"
 )
 
-var (
-	defRegistry   = newDefaultRegistry()
-	errAlreadyReg = errors.New("duplicate metrics collector registration attempted")
-)
-
-// Constants relevant to the HTTP interface.
 const (
-	// APIVersion is the version of the format of the exported data.  This
-	// will match this library's version, which subscribes to the Semantic
-	// Versioning scheme.
-	APIVersion = "0.0.4"
-
-	// DelimitedTelemetryContentType is the content type set on telemetry
-	// data responses in delimited protobuf format.
-	DelimitedTelemetryContentType = `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`
-	// TextTelemetryContentType is the content type set on telemetry data
-	// responses in text format.
-	TextTelemetryContentType = `text/plain; version=` + APIVersion
-	// ProtoTextTelemetryContentType is the content type set on telemetry
-	// data responses in protobuf text format.  (Only used for debugging.)
-	ProtoTextTelemetryContentType = `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=text`
-	// ProtoCompactTextTelemetryContentType is the content type set on
-	// telemetry data responses in protobuf compact text format.  (Only used
-	// for debugging.)
-	ProtoCompactTextTelemetryContentType = `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=compact-text`
-
-	// Constants for object pools.
-	numBufs           = 4
-	numMetricFamilies = 1000
-	numMetrics        = 10000
-
 	// Capacity for the channel to collect metrics and descriptors.
 	capMetricChan = 1000
 	capDescChan   = 10
-
-	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
-	contentEncodingHeader = "Content-Encoding"
-
-	acceptEncodingHeader = "Accept-Encoding"
-	acceptHeader         = "Accept"
 )
 
-// Handler returns the HTTP handler for the global Prometheus registry. It is
-// already instrumented with InstrumentHandler (using "prometheus" as handler
-// name). Usually the handler is used to handle the "/metrics" endpoint.
-func Handler() http.Handler {
-	return InstrumentHandler("prometheus", defRegistry)
+// DefaultRegisterer and DefaultGatherer are the implementations of the
+// Registerer and Gatherer interface a number of convenience functions in this
+// package act on. Initially, both variables point to the same Registry, which
+// has a process collector (see NewProcessCollector) and a Go collector (see
+// NewGoCollector) already registered. This approach to keep default instances
+// as global state mirrors the approach of other packages in the Go standard
+// library. Note that there are caveats. Change the variables with caution and
+// only if you understand the consequences. Users who want to avoid global state
+// altogether should not use the convenience function and act on custom
+// instances instead.
+var (
+	defaultRegistry              = NewRegistry()
+	DefaultRegisterer Registerer = defaultRegistry
+	DefaultGatherer   Gatherer   = defaultRegistry
+)
+
+func init() {
+	MustRegister(NewProcessCollector(os.Getpid(), ""))
+	MustRegister(NewGoCollector())
 }
 
-// UninstrumentedHandler works in the same way as Handler, but the returned HTTP
-// handler is not instrumented. This is useful if no instrumentation is desired
-// (for whatever reason) or if the instrumentation has to happen with a
-// different handler name (or with a different instrumentation approach
-// altogether). See the InstrumentHandler example.
-func UninstrumentedHandler() http.Handler {
-	return defRegistry
-}
-
-// Register registers a new Collector to be included in metrics collection. It
-// returns an error if the descriptors provided by the Collector are invalid or
-// if they - in combination with descriptors of already registered Collectors -
-// do not fulfill the consistency and uniqueness criteria described in the Desc
-// documentation.
-//
-// Do not register the same Collector multiple times concurrently. (Registering
-// the same Collector twice would result in an error anyway, but on top of that,
-// it is not safe to do so concurrently.)
-func Register(m Collector) error {
-	_, err := defRegistry.Register(m)
-	return err
-}
-
-// MustRegister works like Register but panics where Register would have
-// returned an error.
-func MustRegister(m Collector) {
-	err := Register(m)
-	if err != nil {
-		panic(err)
+// NewRegistry creates a new vanilla Registry without any Collectors
+// pre-registered.
+func NewRegistry() *Registry {
+	return &Registry{
+		collectorsByID:  map[uint64]Collector{},
+		descIDs:         map[uint64]struct{}{},
+		dimHashesByName: map[string]uint64{},
 	}
 }
 
-// RegisterOrGet works like Register but does not return an error if a Collector
-// is registered that equals a previously registered Collector. (Two Collectors
-// are considered equal if their Describe method yields the same set of
-// descriptors.) Instead, the previously registered Collector is returned (which
-// is helpful if the new and previously registered Collectors are equal but not
-// identical, i.e. not pointers to the same object).
+// NewPedanticRegistry returns a registry that checks during collection if each
+// collected Metric is consistent with its reported Desc, and if the Desc has
+// actually been registered with the registry.
 //
-// As for Register, it is still not safe to call RegisterOrGet with the same
-// Collector multiple times concurrently.
-func RegisterOrGet(m Collector) (Collector, error) {
-	return defRegistry.RegisterOrGet(m)
+// Usually, a Registry will be happy as long as the union of all collected
+// Metrics is consistent and valid even if some metrics are not consistent with
+// their own Desc or a Desc provided by their registered Collector. Well-behaved
+// Collectors and Metrics will only provide consistent Descs. This Registry is
+// useful to test the implementation of Collectors and Metrics.
+func NewPedanticRegistry() *Registry {
+	r := NewRegistry()
+	r.pedanticChecksEnabled = true
+	return r
 }
 
-// MustRegisterOrGet works like Register but panics where RegisterOrGet would
-// have returned an error.
-func MustRegisterOrGet(m Collector) Collector {
-	existing, err := RegisterOrGet(m)
-	if err != nil {
-		panic(err)
-	}
-	return existing
+// Registerer is the interface for the part of a registry in charge of
+// registering and unregistering. Users of custom registries should use
+// Registerer as type for registration purposes (rather then the Registry type
+// directly). In that way, they are free to use custom Registerer implementation
+// (e.g. for testing purposes).
+type Registerer interface {
+	// Register registers a new Collector to be included in metrics
+	// collection. It returns an error if the descriptors provided by the
+	// Collector are invalid or if they — in combination with descriptors of
+	// already registered Collectors — do not fulfill the consistency and
+	// uniqueness criteria described in the documentation of metric.Desc.
+	//
+	// If the provided Collector is equal to a Collector already registered
+	// (which includes the case of re-registering the same Collector), the
+	// returned error is an instance of AlreadyRegisteredError, which
+	// contains the previously registered Collector.
+	//
+	// It is in general not safe to register the same Collector multiple
+	// times concurrently.
+	Register(Collector) error
+	// MustRegister works like Register but registers any number of
+	// Collectors and panics upon the first registration that causes an
+	// error.
+	MustRegister(...Collector)
+	// Unregister unregisters the Collector that equals the Collector passed
+	// in as an argument.  (Two Collectors are considered equal if their
+	// Describe method yields the same set of descriptors.) The function
+	// returns whether a Collector was unregistered.
+	//
+	// Note that even after unregistering, it will not be possible to
+	// register a new Collector that is inconsistent with the unregistered
+	// Collector, e.g. a Collector collecting metrics with the same name but
+	// a different help string. The rationale here is that the same registry
+	// instance must only collect consistent metrics throughout its
+	// lifetime.
+	Unregister(Collector) bool
 }
 
-// Unregister unregisters the Collector that equals the Collector passed in as
-// an argument. (Two Collectors are considered equal if their Describe method
-// yields the same set of descriptors.) The function returns whether a Collector
-// was unregistered.
+// Gatherer is the interface for the part of a registry in charge of gathering
+// the collected metrics into a number of MetricFamilies. The Gatherer interface
+// comes with the same general implication as described for the Registerer
+// interface.
+type Gatherer interface {
+	// Gather calls the Collect method of the registered Collectors and then
+	// gathers the collected metrics into a lexicographically sorted slice
+	// of MetricFamily protobufs. Even if an error occurs, Gather attempts
+	// to gather as many metrics as possible. Hence, if a non-nil error is
+	// returned, the returned MetricFamily slice could be nil (in case of a
+	// fatal error that prevented any meaningful metric collection) or
+	// contain a number of MetricFamily protobufs, some of which might be
+	// incomplete, and some might be missing altogether. The returned error
+	// (which might be a MultiError) explains the details. In scenarios
+	// where complete collection is critical, the returned MetricFamily
+	// protobufs should be disregarded if the returned error is non-nil.
+	Gather() ([]*dto.MetricFamily, error)
+}
+
+// Register registers the provided Collector with the DefaultRegisterer.
+//
+// Register is a shortcut for DefaultRegisterer.Register(c). See there for more
+// details.
+func Register(c Collector) error {
+	return DefaultRegisterer.Register(c)
+}
+
+// MustRegister registers the provided Collectors with the DefaultRegisterer and
+// panics if any error occurs.
+//
+// MustRegister is a shortcut for DefaultRegisterer.MustRegister(cs...). See
+// there for more details.
+func MustRegister(cs ...Collector) {
+	DefaultRegisterer.MustRegister(cs...)
+}
+
+// Unregister removes the registration of the provided Collector from the
+// DefaultRegisterer.
+//
+// Unregister is a shortcut for DefaultRegisterer.Unregister(c). See there for
+// more details.
 func Unregister(c Collector) bool {
-	return defRegistry.Unregister(c)
+	return DefaultRegisterer.Unregister(c)
 }
 
-// SetMetricFamilyInjectionHook sets a function that is called whenever metrics
-// are collected. The hook function must be set before metrics collection begins
-// (i.e. call SetMetricFamilyInjectionHook before setting the HTTP handler.) The
-// MetricFamily protobufs returned by the hook function are merged with the
-// metrics collected in the usual way.
-//
-// This is a way to directly inject MetricFamily protobufs managed and owned by
-// the caller. The caller has full responsibility. As no registration of the
-// injected metrics has happened, there is no descriptor to check against, and
-// there are no registration-time checks. If collect-time checks are disabled
-// (see function EnableCollectChecks), no sanity checks are performed on the
-// returned protobufs at all. If collect-checks are enabled, type and uniqueness
-// checks are performed, but no further consistency checks (which would require
-// knowledge of a metric descriptor).
-//
-// Sorting concerns: The caller is responsible for sorting the label pairs in
-// each metric. However, the order of metrics will be sorted by the registry as
-// it is required anyway after merging with the metric families collected
-// conventionally.
-//
-// The function must be callable at any time and concurrently.
-func SetMetricFamilyInjectionHook(hook func() []*dto.MetricFamily) {
-	defRegistry.metricFamilyInjectionHook = hook
+// GathererFunc turns a function into a Gatherer.
+type GathererFunc func() ([]*dto.MetricFamily, error)
+
+// Gather implements Gatherer.
+func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) {
+	return gf()
 }
 
-// PanicOnCollectError sets the behavior whether a panic is caused upon an error
-// while metrics are collected and served to the HTTP endpoint. By default, an
-// internal server error (status code 500) is served with an error message.
-func PanicOnCollectError(b bool) {
-	defRegistry.panicOnCollectError = b
+// AlreadyRegisteredError is returned by the Register method if the Collector to
+// be registered has already been registered before, or a different Collector
+// that collects the same metrics has been registered before. Registration fails
+// in that case, but you can detect from the kind of error what has
+// happened. The error contains fields for the existing Collector and the
+// (rejected) new Collector that equals the existing one. This can be used to
+// find out if an equal Collector has been registered before and switch over to
+// using the old one, as demonstrated in the example.
+type AlreadyRegisteredError struct {
+	ExistingCollector, NewCollector Collector
 }
 
-// EnableCollectChecks enables (or disables) additional consistency checks
-// during metrics collection. These additional checks are not enabled by default
-// because they inflict a performance penalty and the errors they check for can
-// only happen if the used Metric and Collector types have internal programming
-// errors. It can be helpful to enable these checks while working with custom
-// Collectors or Metrics whose correctness is not well established yet.
-func EnableCollectChecks(b bool) {
-	defRegistry.collectChecksEnabled = b
+func (err AlreadyRegisteredError) Error() string {
+	return "duplicate metrics collector registration attempted"
 }
 
-// encoder is a function that writes a dto.MetricFamily to an io.Writer in a
-// certain encoding. It returns the number of bytes written and any error
-// encountered.  Note that pbutil.WriteDelimited and pbutil.MetricFamilyToText
-// are encoders.
-type encoder func(io.Writer, *dto.MetricFamily) (int, error)
+// MultiError is a slice of errors implementing the error interface. It is used
+// by a Gatherer to report multiple errors during MetricFamily gathering.
+type MultiError []error
 
-type registry struct {
-	mtx                       sync.RWMutex
-	collectorsByID            map[uint64]Collector // ID is a hash of the descIDs.
-	descIDs                   map[uint64]struct{}
-	dimHashesByName           map[string]uint64
-	bufPool                   chan *bytes.Buffer
-	metricFamilyPool          chan *dto.MetricFamily
-	metricPool                chan *dto.Metric
-	metricFamilyInjectionHook func() []*dto.MetricFamily
-
-	panicOnCollectError, collectChecksEnabled bool
+func (errs MultiError) Error() string {
+	if len(errs) == 0 {
+		return ""
+	}
+	buf := &bytes.Buffer{}
+	fmt.Fprintf(buf, "%d error(s) occurred:", len(errs))
+	for _, err := range errs {
+		fmt.Fprintf(buf, "\n* %s", err)
+	}
+	return buf.String()
 }
 
-func (r *registry) Register(c Collector) (Collector, error) {
-	descChan := make(chan *Desc, capDescChan)
+// MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only
+// contained error as error if len(errs is 1). In all other cases, it returns
+// the MultiError directly. This is helpful for returning a MultiError in a way
+// that only uses the MultiError if needed.
+func (errs MultiError) MaybeUnwrap() error {
+	switch len(errs) {
+	case 0:
+		return nil
+	case 1:
+		return errs[0]
+	default:
+		return errs
+	}
+}
+
+// Registry registers Prometheus collectors, collects their metrics, and gathers
+// them into MetricFamilies for exposition. It implements both Registerer and
+// Gatherer. The zero value is not usable. Create instances with NewRegistry or
+// NewPedanticRegistry.
+type Registry struct {
+	mtx                   sync.RWMutex
+	collectorsByID        map[uint64]Collector // ID is a hash of the descIDs.
+	descIDs               map[uint64]struct{}
+	dimHashesByName       map[string]uint64
+	pedanticChecksEnabled bool
+}
+
+// Register implements Registerer.
+func (r *Registry) Register(c Collector) error {
+	var (
+		descChan           = make(chan *Desc, capDescChan)
+		newDescIDs         = map[uint64]struct{}{}
+		newDimHashesByName = map[string]uint64{}
+		collectorID        uint64 // Just a sum of all desc IDs.
+		duplicateDescErr   error
+	)
 	go func() {
 		c.Describe(descChan)
 		close(descChan)
 	}()
-
-	newDescIDs := map[uint64]struct{}{}
-	newDimHashesByName := map[string]uint64{}
-	var collectorID uint64 // Just a sum of all desc IDs.
-	var duplicateDescErr error
-
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
-	// Coduct various tests...
+	// Conduct various tests...
 	for desc := range descChan {
 
 		// Is the descriptor valid at all?
 		if desc.err != nil {
-			return c, fmt.Errorf("descriptor %s is invalid: %s", desc, desc.err)
+			return fmt.Errorf("descriptor %s is invalid: %s", desc, desc.err)
 		}
 
 		// Is the descID unique?
@@ -253,13 +269,13 @@ func (r *registry) Register(c Collector) (Collector, error) {
 		// First check existing descriptors...
 		if dimHash, exists := r.dimHashesByName[desc.fqName]; exists {
 			if dimHash != desc.dimHash {
-				return nil, fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc)
+				return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc)
 			}
 		} else {
 			// ...then check the new descriptors already seen.
 			if dimHash, exists := newDimHashesByName[desc.fqName]; exists {
 				if dimHash != desc.dimHash {
-					return nil, fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
+					return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
 				}
 			} else {
 				newDimHashesByName[desc.fqName] = desc.dimHash
@@ -268,15 +284,18 @@ func (r *registry) Register(c Collector) (Collector, error) {
 	}
 	// Did anything happen at all?
 	if len(newDescIDs) == 0 {
-		return nil, errors.New("collector has no descriptors")
+		return errors.New("collector has no descriptors")
 	}
 	if existing, exists := r.collectorsByID[collectorID]; exists {
-		return existing, errAlreadyReg
+		return AlreadyRegisteredError{
+			ExistingCollector: existing,
+			NewCollector:      c,
+		}
 	}
 	// If the collectorID is new, but at least one of the descs existed
 	// before, we are in trouble.
 	if duplicateDescErr != nil {
-		return nil, duplicateDescErr
+		return duplicateDescErr
 	}
 
 	// Only after all tests have passed, actually register.
@@ -287,26 +306,20 @@ func (r *registry) Register(c Collector) (Collector, error) {
 	for name, dimHash := range newDimHashesByName {
 		r.dimHashesByName[name] = dimHash
 	}
-	return c, nil
+	return nil
 }
 
-func (r *registry) RegisterOrGet(m Collector) (Collector, error) {
-	existing, err := r.Register(m)
-	if err != nil && err != errAlreadyReg {
-		return nil, err
-	}
-	return existing, nil
-}
-
-func (r *registry) Unregister(c Collector) bool {
-	descChan := make(chan *Desc, capDescChan)
+// Unregister implements Registerer.
+func (r *Registry) Unregister(c Collector) bool {
+	var (
+		descChan    = make(chan *Desc, capDescChan)
+		descIDs     = map[uint64]struct{}{}
+		collectorID uint64 // Just a sum of the desc IDs.
+	)
 	go func() {
 		c.Describe(descChan)
 		close(descChan)
 	}()
-
-	descIDs := map[uint64]struct{}{}
-	var collectorID uint64 // Just a sum of the desc IDs.
 	for desc := range descChan {
 		if _, exists := descIDs[desc.id]; !exists {
 			collectorID += desc.id
@@ -333,69 +346,25 @@ func (r *registry) Unregister(c Collector) bool {
 	return true
 }
 
-func (r *registry) Push(job, instance, pushURL, method string) error {
-	if !strings.Contains(pushURL, "://") {
-		pushURL = "http://" + pushURL
-	}
-	pushURL = fmt.Sprintf("%s/metrics/jobs/%s", pushURL, url.QueryEscape(job))
-	if instance != "" {
-		pushURL += "/instances/" + url.QueryEscape(instance)
-	}
-	buf := r.getBuf()
-	defer r.giveBuf(buf)
-	if err := r.writePB(expfmt.NewEncoder(buf, expfmt.FmtProtoDelim)); err != nil {
-		if r.panicOnCollectError {
+// MustRegister implements Registerer.
+func (r *Registry) MustRegister(cs ...Collector) {
+	for _, c := range cs {
+		if err := r.Register(c); err != nil {
 			panic(err)
 		}
-		return err
 	}
-	req, err := http.NewRequest(method, pushURL, buf)
-	if err != nil {
-		return err
-	}
-	req.Header.Set(contentTypeHeader, DelimitedTelemetryContentType)
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		return err
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode != 202 {
-		return fmt.Errorf("unexpected status code %d while pushing to %s", resp.StatusCode, pushURL)
-	}
-	return nil
 }
 
-func (r *registry) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-	contentType := expfmt.Negotiate(req.Header)
-	buf := r.getBuf()
-	defer r.giveBuf(buf)
-	writer, encoding := decorateWriter(req, buf)
-	if err := r.writePB(expfmt.NewEncoder(writer, contentType)); err != nil {
-		if r.panicOnCollectError {
-			panic(err)
-		}
-		http.Error(w, "An error has occurred:\n\n"+err.Error(), http.StatusInternalServerError)
-		return
-	}
-	if closer, ok := writer.(io.Closer); ok {
-		closer.Close()
-	}
-	header := w.Header()
-	header.Set(contentTypeHeader, string(contentType))
-	header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
-	if encoding != "" {
-		header.Set(contentEncodingHeader, encoding)
-	}
-	w.Write(buf.Bytes())
-}
-
-func (r *registry) writePB(encoder expfmt.Encoder) error {
-	var metricHashes map[uint64]struct{}
-	if r.collectChecksEnabled {
-		metricHashes = make(map[uint64]struct{})
-	}
-	metricChan := make(chan Metric, capMetricChan)
-	wg := sync.WaitGroup{}
+// Gather implements Gatherer.
+func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
+	var (
+		metricChan        = make(chan Metric, capMetricChan)
+		metricHashes      = map[uint64]struct{}{}
+		dimHashes         = map[string]uint64{}
+		wg                sync.WaitGroup
+		errs              MultiError          // The collected errors to return in the end.
+		registeredDescIDs map[uint64]struct{} // Only used for pedantic checks
+	)
 
 	r.mtx.RLock()
 	metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName))
@@ -413,11 +382,21 @@ func (r *registry) writePB(encoder expfmt.Encoder) error {
 			collector.Collect(metricChan)
 		}(collector)
 	}
+
+	// In case pedantic checks are enabled, we have to copy the map before
+	// giving up the RLock.
+	if r.pedanticChecksEnabled {
+		registeredDescIDs = make(map[uint64]struct{}, len(r.descIDs))
+		for id := range r.descIDs {
+			registeredDescIDs[id] = struct{}{}
+		}
+	}
+
 	r.mtx.RUnlock()
 
 	// Drain metricChan in case of premature return.
 	defer func() {
-		for _ = range metricChan {
+		for range metricChan {
 		}
 	}()
 
@@ -427,94 +406,267 @@ func (r *registry) writePB(encoder expfmt.Encoder) error {
 		// of metricFamiliesByName (and of metricHashes if checks are
 		// enabled). Most likely not worth it.
 		desc := metric.Desc()
+		dtoMetric := &dto.Metric{}
+		if err := metric.Write(dtoMetric); err != nil {
+			errs = append(errs, fmt.Errorf(
+				"error collecting metric %v: %s", desc, err,
+			))
+			continue
+		}
 		metricFamily, ok := metricFamiliesByName[desc.fqName]
-		if !ok {
-			metricFamily = r.getMetricFamily()
-			defer r.giveMetricFamily(metricFamily)
+		if ok {
+			if metricFamily.GetHelp() != desc.help {
+				errs = append(errs, fmt.Errorf(
+					"collected metric %s %s has help %q but should have %q",
+					desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(),
+				))
+				continue
+			}
+			// TODO(beorn7): Simplify switch once Desc has type.
+			switch metricFamily.GetType() {
+			case dto.MetricType_COUNTER:
+				if dtoMetric.Counter == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Counter",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_GAUGE:
+				if dtoMetric.Gauge == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Gauge",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_SUMMARY:
+				if dtoMetric.Summary == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Summary",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_UNTYPED:
+				if dtoMetric.Untyped == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be Untyped",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_HISTOGRAM:
+				if dtoMetric.Histogram == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Histogram",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			default:
+				panic("encountered MetricFamily with invalid type")
+			}
+		} else {
+			metricFamily = &dto.MetricFamily{}
 			metricFamily.Name = proto.String(desc.fqName)
 			metricFamily.Help = proto.String(desc.help)
+			// TODO(beorn7): Simplify switch once Desc has type.
+			switch {
+			case dtoMetric.Gauge != nil:
+				metricFamily.Type = dto.MetricType_GAUGE.Enum()
+			case dtoMetric.Counter != nil:
+				metricFamily.Type = dto.MetricType_COUNTER.Enum()
+			case dtoMetric.Summary != nil:
+				metricFamily.Type = dto.MetricType_SUMMARY.Enum()
+			case dtoMetric.Untyped != nil:
+				metricFamily.Type = dto.MetricType_UNTYPED.Enum()
+			case dtoMetric.Histogram != nil:
+				metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
+			default:
+				errs = append(errs, fmt.Errorf(
+					"empty metric collected: %s", dtoMetric,
+				))
+				continue
+			}
 			metricFamiliesByName[desc.fqName] = metricFamily
 		}
-		dtoMetric := r.getMetric()
-		defer r.giveMetric(dtoMetric)
-		if err := metric.Write(dtoMetric); err != nil {
-			// TODO: Consider different means of error reporting so
-			// that a single erroneous metric could be skipped
-			// instead of blowing up the whole collection.
-			return fmt.Errorf("error collecting metric %v: %s", desc, err)
+		if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil {
+			errs = append(errs, err)
+			continue
 		}
-		switch {
-		case metricFamily.Type != nil:
-			// Type already set. We are good.
-		case dtoMetric.Gauge != nil:
-			metricFamily.Type = dto.MetricType_GAUGE.Enum()
-		case dtoMetric.Counter != nil:
-			metricFamily.Type = dto.MetricType_COUNTER.Enum()
-		case dtoMetric.Summary != nil:
-			metricFamily.Type = dto.MetricType_SUMMARY.Enum()
-		case dtoMetric.Untyped != nil:
-			metricFamily.Type = dto.MetricType_UNTYPED.Enum()
-		case dtoMetric.Histogram != nil:
-			metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
-		default:
-			return fmt.Errorf("empty metric collected: %s", dtoMetric)
-		}
-		if r.collectChecksEnabled {
-			if err := r.checkConsistency(metricFamily, dtoMetric, desc, metricHashes); err != nil {
-				return err
+		if r.pedanticChecksEnabled {
+			// Is the desc registered at all?
+			if _, exist := registeredDescIDs[desc.id]; !exist {
+				errs = append(errs, fmt.Errorf(
+					"collected metric %s %s with unregistered descriptor %s",
+					metricFamily.GetName(), dtoMetric, desc,
+				))
+				continue
+			}
+			if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil {
+				errs = append(errs, err)
+				continue
 			}
 		}
 		metricFamily.Metric = append(metricFamily.Metric, dtoMetric)
 	}
+	return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+}
 
-	if r.metricFamilyInjectionHook != nil {
-		for _, mf := range r.metricFamilyInjectionHook() {
-			existingMF, exists := metricFamiliesByName[mf.GetName()]
-			if !exists {
-				metricFamiliesByName[mf.GetName()] = mf
-				if r.collectChecksEnabled {
-					for _, m := range mf.Metric {
-						if err := r.checkConsistency(mf, m, nil, metricHashes); err != nil {
-							return err
-						}
-					}
+// Gatherers is a slice of Gatherer instances that implements the Gatherer
+// interface itself. Its Gather method calls Gather on all Gatherers in the
+// slice in order and returns the merged results. Errors returned from the
+// Gather calles are all returned in a flattened MultiError. Duplicate and
+// inconsistent Metrics are skipped (first occurrence in slice order wins) and
+// reported in the returned error.
+//
+// Gatherers can be used to merge the Gather results from multiple
+// Registries. It also provides a way to directly inject existing MetricFamily
+// protobufs into the gathering by creating a custom Gatherer with a Gather
+// method that simply returns the existing MetricFamily protobufs. Note that no
+// registration is involved (in contrast to Collector registration), so
+// obviously registration-time checks cannot happen. Any inconsistencies between
+// the gathered MetricFamilies are reported as errors by the Gather method, and
+// inconsistent Metrics are dropped. Invalid parts of the MetricFamilies
+// (e.g. syntactically invalid metric or label names) will go undetected.
+type Gatherers []Gatherer
+
+// Gather implements Gatherer.
+func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
+	var (
+		metricFamiliesByName = map[string]*dto.MetricFamily{}
+		metricHashes         = map[uint64]struct{}{}
+		dimHashes            = map[string]uint64{}
+		errs                 MultiError // The collected errors to return in the end.
+	)
+
+	for i, g := range gs {
+		mfs, err := g.Gather()
+		if err != nil {
+			if multiErr, ok := err.(MultiError); ok {
+				for _, err := range multiErr {
+					errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
 				}
-				continue
+			} else {
+				errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
+			}
+		}
+		for _, mf := range mfs {
+			existingMF, exists := metricFamiliesByName[mf.GetName()]
+			if exists {
+				if existingMF.GetHelp() != mf.GetHelp() {
+					errs = append(errs, fmt.Errorf(
+						"gathered metric family %s has help %q but should have %q",
+						mf.GetName(), mf.GetHelp(), existingMF.GetHelp(),
+					))
+					continue
+				}
+				if existingMF.GetType() != mf.GetType() {
+					errs = append(errs, fmt.Errorf(
+						"gathered metric family %s has type %s but should have %s",
+						mf.GetName(), mf.GetType(), existingMF.GetType(),
+					))
+					continue
+				}
+			} else {
+				existingMF = &dto.MetricFamily{}
+				existingMF.Name = mf.Name
+				existingMF.Help = mf.Help
+				existingMF.Type = mf.Type
+				metricFamiliesByName[mf.GetName()] = existingMF
 			}
 			for _, m := range mf.Metric {
-				if r.collectChecksEnabled {
-					if err := r.checkConsistency(existingMF, m, nil, metricHashes); err != nil {
-						return err
-					}
+				if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil {
+					errs = append(errs, err)
+					continue
 				}
 				existingMF.Metric = append(existingMF.Metric, m)
 			}
 		}
 	}
+	return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+}
 
-	// Now that MetricFamilies are all set, sort their Metrics
-	// lexicographically by their label values.
+// metricSorter is a sortable slice of *dto.Metric.
+type metricSorter []*dto.Metric
+
+func (s metricSorter) Len() int {
+	return len(s)
+}
+
+func (s metricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s metricSorter) Less(i, j int) bool {
+	if len(s[i].Label) != len(s[j].Label) {
+		// This should not happen. The metrics are
+		// inconsistent. However, we have to deal with the fact, as
+		// people might use custom collectors or metric family injection
+		// to create inconsistent metrics. So let's simply compare the
+		// number of labels in this case. That will still yield
+		// reproducible sorting.
+		return len(s[i].Label) < len(s[j].Label)
+	}
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	// We should never arrive here. Multiple metrics with the same
+	// label set in the same scrape will lead to undefined ingestion
+	// behavior. However, as above, we have to provide stable sorting
+	// here, even for inconsistent metrics. So sort equal metrics
+	// by their timestamp, with missing timestamps (implying "now")
+	// coming last.
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// normalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
 	for _, mf := range metricFamiliesByName {
 		sort.Sort(metricSorter(mf.Metric))
 	}
-
-	// Write out MetricFamilies sorted by their name.
 	names := make([]string, 0, len(metricFamiliesByName))
-	for name := range metricFamiliesByName {
-		names = append(names, name)
-	}
-	sort.Strings(names)
-
-	for _, name := range names {
-		if err := encoder.Encode(metricFamiliesByName[name]); err != nil {
-			return err
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
 		}
 	}
-	return nil
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
 }
 
-func (r *registry) checkConsistency(metricFamily *dto.MetricFamily, dtoMetric *dto.Metric, desc *Desc, metricHashes map[uint64]struct{}) error {
-
+// checkMetricConsistency checks if the provided Metric is consistent with the
+// provided MetricFamily. It also hashed the Metric labels and the MetricFamily
+// name. If the resulting hash is alread in the provided metricHashes, an error
+// is returned. If not, it is added to metricHashes. The provided dimHashes maps
+// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes
+// doesn't yet contain a hash for the provided MetricFamily, it is
+// added. Otherwise, an error is returned if the existing dimHashes in not equal
+// the calculated dimHash.
+func checkMetricConsistency(
+	metricFamily *dto.MetricFamily,
+	dtoMetric *dto.Metric,
+	metricHashes map[uint64]struct{},
+	dimHashes map[string]uint64,
+) error {
 	// Type consistency with metric family.
 	if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil ||
 		metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil ||
@@ -528,42 +680,45 @@ func (r *registry) checkConsistency(metricFamily *dto.MetricFamily, dtoMetric *d
 	}
 
 	// Is the metric unique (i.e. no other metric with the same name and the same label values)?
-	h := fnv.New64a()
-	var buf bytes.Buffer
-	buf.WriteString(metricFamily.GetName())
-	buf.WriteByte(separatorByte)
-	h.Write(buf.Bytes())
+	h := hashNew()
+	h = hashAdd(h, metricFamily.GetName())
+	h = hashAddByte(h, separatorByte)
+	dh := hashNew()
 	// Make sure label pairs are sorted. We depend on it for the consistency
-	// check. Label pairs must be sorted by contract. But the point of this
-	// method is to check for contract violations. So we better do the sort
-	// now.
+	// check.
 	sort.Sort(LabelPairSorter(dtoMetric.Label))
 	for _, lp := range dtoMetric.Label {
-		buf.Reset()
-		buf.WriteString(lp.GetValue())
-		buf.WriteByte(separatorByte)
-		h.Write(buf.Bytes())
+		h = hashAdd(h, lp.GetValue())
+		h = hashAddByte(h, separatorByte)
+		dh = hashAdd(dh, lp.GetName())
+		dh = hashAddByte(dh, separatorByte)
 	}
-	metricHash := h.Sum64()
-	if _, exists := metricHashes[metricHash]; exists {
+	if _, exists := metricHashes[h]; exists {
 		return fmt.Errorf(
 			"collected metric %s %s was collected before with the same name and label values",
 			metricFamily.GetName(), dtoMetric,
 		)
 	}
-	metricHashes[metricHash] = struct{}{}
-
-	if desc == nil {
-		return nil // Nothing left to check if we have no desc.
+	if dimHash, ok := dimHashes[metricFamily.GetName()]; ok {
+		if dimHash != dh {
+			return fmt.Errorf(
+				"collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family",
+				metricFamily.GetName(), dtoMetric,
+			)
+		}
+	} else {
+		dimHashes[metricFamily.GetName()] = dh
 	}
+	metricHashes[h] = struct{}{}
+	return nil
+}
 
-	// Desc consistency with metric family.
-	if metricFamily.GetName() != desc.fqName {
-		return fmt.Errorf(
-			"collected metric %s %s has name %q but should have %q",
-			metricFamily.GetName(), dtoMetric, metricFamily.GetName(), desc.fqName,
-		)
-	}
+func checkDescConsistency(
+	metricFamily *dto.MetricFamily,
+	dtoMetric *dto.Metric,
+	desc *Desc,
+) error {
+	// Desc help consistency with metric family help.
 	if metricFamily.GetHelp() != desc.help {
 		return fmt.Errorf(
 			"collected metric %s %s has help %q but should have %q",
@@ -596,131 +751,5 @@ func (r *registry) checkConsistency(metricFamily *dto.MetricFamily, dtoMetric *d
 			)
 		}
 	}
-
-	r.mtx.RLock() // Remaining checks need the read lock.
-	defer r.mtx.RUnlock()
-
-	// Is the desc registered?
-	if _, exist := r.descIDs[desc.id]; !exist {
-		return fmt.Errorf(
-			"collected metric %s %s with unregistered descriptor %s",
-			metricFamily.GetName(), dtoMetric, desc,
-		)
-	}
-
 	return nil
 }
-
-func (r *registry) getBuf() *bytes.Buffer {
-	select {
-	case buf := <-r.bufPool:
-		return buf
-	default:
-		return &bytes.Buffer{}
-	}
-}
-
-func (r *registry) giveBuf(buf *bytes.Buffer) {
-	buf.Reset()
-	select {
-	case r.bufPool <- buf:
-	default:
-	}
-}
-
-func (r *registry) getMetricFamily() *dto.MetricFamily {
-	select {
-	case mf := <-r.metricFamilyPool:
-		return mf
-	default:
-		return &dto.MetricFamily{}
-	}
-}
-
-func (r *registry) giveMetricFamily(mf *dto.MetricFamily) {
-	mf.Reset()
-	select {
-	case r.metricFamilyPool <- mf:
-	default:
-	}
-}
-
-func (r *registry) getMetric() *dto.Metric {
-	select {
-	case m := <-r.metricPool:
-		return m
-	default:
-		return &dto.Metric{}
-	}
-}
-
-func (r *registry) giveMetric(m *dto.Metric) {
-	m.Reset()
-	select {
-	case r.metricPool <- m:
-	default:
-	}
-}
-
-func newRegistry() *registry {
-	return &registry{
-		collectorsByID:   map[uint64]Collector{},
-		descIDs:          map[uint64]struct{}{},
-		dimHashesByName:  map[string]uint64{},
-		bufPool:          make(chan *bytes.Buffer, numBufs),
-		metricFamilyPool: make(chan *dto.MetricFamily, numMetricFamilies),
-		metricPool:       make(chan *dto.Metric, numMetrics),
-	}
-}
-
-func newDefaultRegistry() *registry {
-	r := newRegistry()
-	r.Register(NewProcessCollector(os.Getpid(), ""))
-	r.Register(NewGoCollector())
-	return r
-}
-
-// decorateWriter wraps a writer to handle gzip compression if requested.  It
-// returns the decorated writer and the appropriate "Content-Encoding" header
-// (which is empty if no compression is enabled).
-func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
-	header := request.Header.Get(acceptEncodingHeader)
-	parts := strings.Split(header, ",")
-	for _, part := range parts {
-		part := strings.TrimSpace(part)
-		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
-			return gzip.NewWriter(writer), "gzip"
-		}
-	}
-	return writer, ""
-}
-
-type metricSorter []*dto.Metric
-
-func (s metricSorter) Len() int {
-	return len(s)
-}
-
-func (s metricSorter) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-func (s metricSorter) Less(i, j int) bool {
-	if len(s[i].Label) != len(s[j].Label) {
-		// This should not happen. The metrics are
-		// inconsistent. However, we have to deal with the fact, as
-		// people might use custom collectors or metric family injection
-		// to create inconsistent metrics. So let's simply compare the
-		// number of labels in this case. That will still yield
-		// reproducible sorting.
-		return len(s[i].Label) < len(s[j].Label)
-	}
-	for n, lp := range s[i].Label {
-		vi := lp.GetValue()
-		vj := s[j].Label[n].GetValue()
-		if vi != vj {
-			return vi < vj
-		}
-	}
-	return true
-}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/summary.go b/vendor/github.com/prometheus/client_golang/prometheus/summary.go
index fe81e004..82b88501 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/summary.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/summary.go
@@ -15,7 +15,6 @@ package prometheus
 
 import (
 	"fmt"
-	"hash/fnv"
 	"math"
 	"sort"
 	"sync"
@@ -54,8 +53,11 @@ type Summary interface {
 	Observe(float64)
 }
 
+// DefObjectives are the default Summary quantile values.
+//
+// Deprecated: DefObjectives will not be used as the default objectives in
+// v0.10 of the library. The default Summary will have no quantiles then.
 var (
-	// DefObjectives are the default Summary quantile values.
 	DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
 
 	errQuantileLabelNotAllowed = fmt.Errorf(
@@ -114,9 +116,15 @@ type SummaryOpts struct {
 	ConstLabels Labels
 
 	// Objectives defines the quantile rank estimates with their respective
-	// absolute error. If Objectives[q] = e, then the value reported
-	// for q will be the φ-quantile value for some φ between q-e and q+e.
-	// The default value is DefObjectives.
+	// absolute error. If Objectives[q] = e, then the value reported for q
+	// will be the φ-quantile value for some φ between q-e and q+e.  The
+	// default value is DefObjectives. It is used if Objectives is left at
+	// its zero value (i.e. nil). To create a Summary without Objectives,
+	// set it to an empty map (i.e. map[float64]float64{}).
+	//
+	// Deprecated: Note that the current value of DefObjectives is
+	// deprecated. It will be replaced by an empty map in v0.10 of the
+	// library. Please explicitly set Objectives to the desired value.
 	Objectives map[float64]float64
 
 	// MaxAge defines the duration for which an observation stays relevant
@@ -140,11 +148,11 @@ type SummaryOpts struct {
 	BufCap uint32
 }
 
-// TODO: Great fuck-up with the sliding-window decay algorithm... The Merge
-// method of perk/quantile is actually not working as advertised - and it might
-// be unfixable, as the underlying algorithm is apparently not capable of
-// merging summaries in the first place. To avoid using Merge, we are currently
-// adding observations to _each_ age bucket, i.e. the effort to add a sample is
+// Great fuck-up with the sliding-window decay algorithm... The Merge method of
+// perk/quantile is actually not working as advertised - and it might be
+// unfixable, as the underlying algorithm is apparently not capable of merging
+// summaries in the first place. To avoid using Merge, we are currently adding
+// observations to _each_ age bucket, i.e. the effort to add a sample is
 // essentially multiplied by the number of age buckets. When rotating age
 // buckets, we empty the previous head stream. On scrape time, we simply take
 // the quantiles from the head stream (no merging required). Result: More effort
@@ -184,7 +192,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 		}
 	}
 
-	if len(opts.Objectives) == 0 {
+	if opts.Objectives == nil {
 		opts.Objectives = DefObjectives
 	}
 
@@ -228,12 +236,12 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 	}
 	sort.Float64s(s.sortedObjectives)
 
-	s.Init(s) // Init self-collection.
+	s.init(s) // Init self-collection.
 	return s
 }
 
 type summary struct {
-	SelfCollector
+	selfCollector
 
 	bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime.
 	mtx    sync.Mutex // Protects every other moving part.
@@ -391,7 +399,7 @@ func (s quantSort) Less(i, j int) bool {
 // (e.g. HTTP request latencies, partitioned by status code and method). Create
 // instances with NewSummaryVec.
 type SummaryVec struct {
-	MetricVec
+	*MetricVec
 }
 
 // NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
@@ -405,14 +413,9 @@ func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
 		opts.ConstLabels,
 	)
 	return &SummaryVec{
-		MetricVec: MetricVec{
-			children: map[uint64]Metric{},
-			desc:     desc,
-			hash:     fnv.New64a(),
-			newMetric: func(lvs ...string) Metric {
-				return newSummary(desc, opts, lvs...)
-			},
-		},
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newSummary(desc, opts, lvs...)
+		}),
 	}
 }
 
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/timer.go b/vendor/github.com/prometheus/client_golang/prometheus/timer.go
new file mode 100644
index 00000000..f4cac5a0
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/timer.go
@@ -0,0 +1,74 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import "time"
+
+// Observer is the interface that wraps the Observe method, which is used by
+// Histogram and Summary to add observations.
+type Observer interface {
+	Observe(float64)
+}
+
+// The ObserverFunc type is an adapter to allow the use of ordinary
+// functions as Observers. If f is a function with the appropriate
+// signature, ObserverFunc(f) is an Observer that calls f.
+//
+// This adapter is usually used in connection with the Timer type, and there are
+// two general use cases:
+//
+// The most common one is to use a Gauge as the Observer for a Timer.
+// See the "Gauge" Timer example.
+//
+// The more advanced use case is to create a function that dynamically decides
+// which Observer to use for observing the duration. See the "Complex" Timer
+// example.
+type ObserverFunc func(float64)
+
+// Observe calls f(value). It implements Observer.
+func (f ObserverFunc) Observe(value float64) {
+	f(value)
+}
+
+// Timer is a helper type to time functions. Use NewTimer to create new
+// instances.
+type Timer struct {
+	begin    time.Time
+	observer Observer
+}
+
+// NewTimer creates a new Timer. The provided Observer is used to observe a
+// duration in seconds. Timer is usually used to time a function call in the
+// following way:
+//    func TimeMe() {
+//        timer := NewTimer(myHistogram)
+//        defer timer.ObserveDuration()
+//        // Do actual work.
+//    }
+func NewTimer(o Observer) *Timer {
+	return &Timer{
+		begin:    time.Now(),
+		observer: o,
+	}
+}
+
+// ObserveDuration records the duration passed since the Timer was created with
+// NewTimer. It calls the Observe method of the Observer provided during
+// construction with the duration in seconds as an argument. ObserveDuration is
+// usually called with a defer statement.
+func (t *Timer) ObserveDuration() {
+	if t.observer != nil {
+		t.observer.Observe(time.Since(t.begin).Seconds())
+	}
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/untyped.go b/vendor/github.com/prometheus/client_golang/prometheus/untyped.go
index c65ab1c5..065501d3 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/untyped.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/untyped.go
@@ -13,8 +13,6 @@
 
 package prometheus
 
-import "hash/fnv"
-
 // Untyped is a Metric that represents a single numerical value that can
 // arbitrarily go up and down.
 //
@@ -22,6 +20,11 @@ import "hash/fnv"
 // no type information is implied.
 //
 // To create Untyped instances, use NewUntyped.
+//
+// Deprecated: The Untyped type is deprecated because it doesn't make sense in
+// direct instrumentation. If you need to mirror an external metric of unknown
+// type (usually while writing exporters), Use MustNewConstMetric to create an
+// untyped metric instance on the fly.
 type Untyped interface {
 	Metric
 	Collector
@@ -58,7 +61,7 @@ func NewUntyped(opts UntypedOpts) Untyped {
 // labels. This is used if you want to count the same thing partitioned by
 // various dimensions. Create instances with NewUntypedVec.
 type UntypedVec struct {
-	MetricVec
+	*MetricVec
 }
 
 // NewUntypedVec creates a new UntypedVec based on the provided UntypedOpts and
@@ -72,14 +75,9 @@ func NewUntypedVec(opts UntypedOpts, labelNames []string) *UntypedVec {
 		opts.ConstLabels,
 	)
 	return &UntypedVec{
-		MetricVec: MetricVec{
-			children: map[uint64]Metric{},
-			desc:     desc,
-			hash:     fnv.New64a(),
-			newMetric: func(lvs ...string) Metric {
-				return newValue(desc, UntypedValue, 0, lvs...)
-			},
-		},
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newValue(desc, UntypedValue, 0, lvs...)
+		}),
 	}
 }
 
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/value.go b/vendor/github.com/prometheus/client_golang/prometheus/value.go
index b54ac11e..ff75ce58 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/value.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/value.go
@@ -19,6 +19,7 @@ import (
 	"math"
 	"sort"
 	"sync/atomic"
+	"time"
 
 	dto "github.com/prometheus/client_model/go"
 
@@ -43,12 +44,12 @@ var errInconsistentCardinality = errors.New("inconsistent label cardinality")
 // ValueType. This is a low-level building block used by the library to back the
 // implementations of Counter, Gauge, and Untyped.
 type value struct {
-	// valBits containst the bits of the represented float64 value. It has
+	// valBits contains the bits of the represented float64 value. It has
 	// to go first in the struct to guarantee alignment for atomic
 	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
 	valBits uint64
 
-	SelfCollector
+	selfCollector
 
 	desc       *Desc
 	valType    ValueType
@@ -68,7 +69,7 @@ func newValue(desc *Desc, valueType ValueType, val float64, labelValues ...strin
 		valBits:    math.Float64bits(val),
 		labelPairs: makeLabelPairs(desc, labelValues),
 	}
-	result.Init(result)
+	result.init(result)
 	return result
 }
 
@@ -80,6 +81,10 @@ func (v *value) Set(val float64) {
 	atomic.StoreUint64(&v.valBits, math.Float64bits(val))
 }
 
+func (v *value) SetToCurrentTime() {
+	v.Set(float64(time.Now().UnixNano()) / 1e9)
+}
+
 func (v *value) Inc() {
 	v.Add(1)
 }
@@ -113,7 +118,7 @@ func (v *value) Write(out *dto.Metric) error {
 // library to back the implementations of CounterFunc, GaugeFunc, and
 // UntypedFunc.
 type valueFunc struct {
-	SelfCollector
+	selfCollector
 
 	desc       *Desc
 	valType    ValueType
@@ -134,7 +139,7 @@ func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *val
 		function:   function,
 		labelPairs: makeLabelPairs(desc, nil),
 	}
-	result.Init(result)
+	result.init(result)
 	return result
 }
 
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/vec.go b/vendor/github.com/prometheus/client_golang/prometheus/vec.go
index a1f3bdf3..7f3eef9a 100644
--- a/vendor/github.com/prometheus/client_golang/prometheus/vec.go
+++ b/vendor/github.com/prometheus/client_golang/prometheus/vec.go
@@ -14,10 +14,10 @@
 package prometheus
 
 import (
-	"bytes"
 	"fmt"
-	"hash"
 	"sync"
+
+	"github.com/prometheus/common/model"
 )
 
 // MetricVec is a Collector to bundle metrics of the same name that
@@ -26,17 +26,32 @@ import (
 // type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already
 // provided in this package.
 type MetricVec struct {
-	mtx      sync.RWMutex // Protects not only children, but also hash and buf.
-	children map[uint64]Metric
+	mtx      sync.RWMutex // Protects the children.
+	children map[uint64][]metricWithLabelValues
 	desc     *Desc
 
-	// hash is our own hash instance to avoid repeated allocations.
-	hash hash.Hash64
-	// buf is used to copy string contents into it for hashing,
-	// again to avoid allocations.
-	buf bytes.Buffer
+	newMetric   func(labelValues ...string) Metric
+	hashAdd     func(h uint64, s string) uint64 // replace hash function for testing collision handling
+	hashAddByte func(h uint64, b byte) uint64
+}
 
-	newMetric func(labelValues ...string) Metric
+// newMetricVec returns an initialized MetricVec. The concrete value is
+// returned for embedding into another struct.
+func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
+	return &MetricVec{
+		children:    map[uint64][]metricWithLabelValues{},
+		desc:        desc,
+		newMetric:   newMetric,
+		hashAdd:     hashAdd,
+		hashAddByte: hashAddByte,
+	}
+}
+
+// metricWithLabelValues provides the metric and its label values for
+// disambiguation on hash collision.
+type metricWithLabelValues struct {
+	values []string
+	metric Metric
 }
 
 // Describe implements Collector. The length of the returned slice
@@ -50,8 +65,10 @@ func (m *MetricVec) Collect(ch chan<- Metric) {
 	m.mtx.RLock()
 	defer m.mtx.RUnlock()
 
-	for _, metric := range m.children {
-		ch <- metric
+	for _, metrics := range m.children {
+		for _, metric := range metrics {
+			ch <- metric.metric
+		}
 	}
 }
 
@@ -80,14 +97,12 @@ func (m *MetricVec) Collect(ch chan<- Metric) {
 // with a performance overhead (for creating and processing the Labels map).
 // See also the GaugeVec example.
 func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
 	h, err := m.hashLabelValues(lvs)
 	if err != nil {
 		return nil, err
 	}
-	return m.getOrCreateMetric(h, lvs...), nil
+
+	return m.getOrCreateMetricWithLabelValues(h, lvs), nil
 }
 
 // GetMetricWith returns the Metric for the given Labels map (the label names
@@ -103,18 +118,12 @@ func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
 // GetMetricWithLabelValues(...string). See there for pros and cons of the two
 // methods.
 func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
 	h, err := m.hashLabels(labels)
 	if err != nil {
 		return nil, err
 	}
-	lvs := make([]string, len(labels))
-	for i, label := range m.desc.variableLabels {
-		lvs[i] = labels[label]
-	}
-	return m.getOrCreateMetric(h, lvs...), nil
+
+	return m.getOrCreateMetricWithLabels(h, labels), nil
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics if an error
@@ -162,11 +171,7 @@ func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
 	if err != nil {
 		return false
 	}
-	if _, has := m.children[h]; !has {
-		return false
-	}
-	delete(m.children, h)
-	return true
+	return m.deleteByHashWithLabelValues(h, lvs)
 }
 
 // Delete deletes the metric where the variable labels are the same as those
@@ -187,10 +192,50 @@ func (m *MetricVec) Delete(labels Labels) bool {
 	if err != nil {
 		return false
 	}
-	if _, has := m.children[h]; !has {
+
+	return m.deleteByHashWithLabels(h, labels)
+}
+
+// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
+// there are multiple matches in the bucket, use lvs to select a metric and
+// remove only that metric.
+func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
+	metrics, ok := m.children[h]
+	if !ok {
 		return false
 	}
-	delete(m.children, h)
+
+	i := m.findMetricWithLabelValues(metrics, lvs)
+	if i >= len(metrics) {
+		return false
+	}
+
+	if len(metrics) > 1 {
+		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+	} else {
+		delete(m.children, h)
+	}
+	return true
+}
+
+// deleteByHashWithLabels removes the metric from the hash bucket h. If there
+// are multiple matches in the bucket, use lvs to select a metric and remove
+// only that metric.
+func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool {
+	metrics, ok := m.children[h]
+	if !ok {
+		return false
+	}
+	i := m.findMetricWithLabels(metrics, labels)
+	if i >= len(metrics) {
+		return false
+	}
+
+	if len(metrics) > 1 {
+		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+	} else {
+		delete(m.children, h)
+	}
 	return true
 }
 
@@ -208,40 +253,152 @@ func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
 	if len(vals) != len(m.desc.variableLabels) {
 		return 0, errInconsistentCardinality
 	}
-	m.hash.Reset()
+	h := hashNew()
 	for _, val := range vals {
-		m.buf.Reset()
-		m.buf.WriteString(val)
-		m.hash.Write(m.buf.Bytes())
+		h = m.hashAdd(h, val)
+		h = m.hashAddByte(h, model.SeparatorByte)
 	}
-	return m.hash.Sum64(), nil
+	return h, nil
 }
 
 func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
 	if len(labels) != len(m.desc.variableLabels) {
 		return 0, errInconsistentCardinality
 	}
-	m.hash.Reset()
+	h := hashNew()
 	for _, label := range m.desc.variableLabels {
 		val, ok := labels[label]
 		if !ok {
 			return 0, fmt.Errorf("label name %q missing in label map", label)
 		}
-		m.buf.Reset()
-		m.buf.WriteString(val)
-		m.hash.Write(m.buf.Bytes())
+		h = m.hashAdd(h, val)
+		h = m.hashAddByte(h, model.SeparatorByte)
 	}
-	return m.hash.Sum64(), nil
+	return h, nil
 }
 
-func (m *MetricVec) getOrCreateMetric(hash uint64, labelValues ...string) Metric {
-	metric, ok := m.children[hash]
+// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// or creates it and returns the new one.
+//
+// This function holds the mutex.
+func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric {
+	m.mtx.RLock()
+	metric, ok := m.getMetricWithLabelValues(hash, lvs)
+	m.mtx.RUnlock()
+	if ok {
+		return metric
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	metric, ok = m.getMetricWithLabelValues(hash, lvs)
 	if !ok {
-		// Copy labelValues. Otherwise, they would be allocated even if we don't go
-		// down this code path.
-		copiedLabelValues := append(make([]string, 0, len(labelValues)), labelValues...)
-		metric = m.newMetric(copiedLabelValues...)
-		m.children[hash] = metric
+		// Copy to avoid allocation in case wo don't go down this code path.
+		copiedLVs := make([]string, len(lvs))
+		copy(copiedLVs, lvs)
+		metric = m.newMetric(copiedLVs...)
+		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric})
 	}
 	return metric
 }
+
+// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// or creates it and returns the new one.
+//
+// This function holds the mutex.
+func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric {
+	m.mtx.RLock()
+	metric, ok := m.getMetricWithLabels(hash, labels)
+	m.mtx.RUnlock()
+	if ok {
+		return metric
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	metric, ok = m.getMetricWithLabels(hash, labels)
+	if !ok {
+		lvs := m.extractLabelValues(labels)
+		metric = m.newMetric(lvs...)
+		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric})
+	}
+	return metric
+}
+
+// getMetricWithLabelValues gets a metric while handling possible collisions in
+// the hash space. Must be called while holding read mutex.
+func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) {
+	metrics, ok := m.children[h]
+	if ok {
+		if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) {
+			return metrics[i].metric, true
+		}
+	}
+	return nil, false
+}
+
+// getMetricWithLabels gets a metric while handling possible collisions in
+// the hash space. Must be called while holding read mutex.
+func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) {
+	metrics, ok := m.children[h]
+	if ok {
+		if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) {
+			return metrics[i].metric, true
+		}
+	}
+	return nil, false
+}
+
+// findMetricWithLabelValues returns the index of the matching metric or
+// len(metrics) if not found.
+func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int {
+	for i, metric := range metrics {
+		if m.matchLabelValues(metric.values, lvs) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+// findMetricWithLabels returns the index of the matching metric or len(metrics)
+// if not found.
+func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int {
+	for i, metric := range metrics {
+		if m.matchLabels(metric.values, labels) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool {
+	if len(values) != len(lvs) {
+		return false
+	}
+	for i, v := range values {
+		if v != lvs[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
+	if len(labels) != len(values) {
+		return false
+	}
+	for i, k := range m.desc.variableLabels {
+		if values[i] != labels[k] {
+			return false
+		}
+	}
+	return true
+}
+
+func (m *MetricVec) extractLabelValues(labels Labels) []string {
+	labelValues := make([]string, len(labels))
+	for i, k := range m.desc.variableLabels {
+		labelValues[i] = labels[k]
+	}
+	return labelValues
+}
diff --git a/vendor/github.com/prometheus/common/LICENSE b/vendor/github.com/prometheus/common/LICENSE
new file mode 100644
index 00000000..261eeb9e
--- /dev/null
+++ b/vendor/github.com/prometheus/common/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/prometheus/common/NOTICE b/vendor/github.com/prometheus/common/NOTICE
new file mode 100644
index 00000000..636a2c1a
--- /dev/null
+++ b/vendor/github.com/prometheus/common/NOTICE
@@ -0,0 +1,5 @@
+Common libraries shared by Prometheus Go components.
+Copyright 2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
diff --git a/vendor/github.com/prometheus/common/expfmt/decode.go b/vendor/github.com/prometheus/common/expfmt/decode.go
index b72c9bed..a7a42d5e 100644
--- a/vendor/github.com/prometheus/common/expfmt/decode.go
+++ b/vendor/github.com/prometheus/common/expfmt/decode.go
@@ -31,6 +31,7 @@ type Decoder interface {
 	Decode(*dto.MetricFamily) error
 }
 
+// DecodeOptions contains options used by the Decoder and in sample extraction.
 type DecodeOptions struct {
 	// Timestamp is added to each value from the stream that has no explicit timestamp set.
 	Timestamp model.Time
@@ -46,10 +47,7 @@ func ResponseFormat(h http.Header) Format {
 		return FmtUnknown
 	}
 
-	const (
-		textType = "text/plain"
-		jsonType = "application/json"
-	)
+	const textType = "text/plain"
 
 	switch mediatype {
 	case ProtoType:
@@ -66,22 +64,6 @@ func ResponseFormat(h http.Header) Format {
 			return FmtUnknown
 		}
 		return FmtText
-
-	case jsonType:
-		var prometheusAPIVersion string
-
-		if params["schema"] == "prometheus/telemetry" && params["version"] != "" {
-			prometheusAPIVersion = params["version"]
-		} else {
-			prometheusAPIVersion = h.Get("X-Prometheus-API-Version")
-		}
-
-		switch prometheusAPIVersion {
-		case "0.0.2", "":
-			return fmtJSON2
-		default:
-			return FmtUnknown
-		}
 	}
 
 	return FmtUnknown
@@ -93,8 +75,6 @@ func NewDecoder(r io.Reader, format Format) Decoder {
 	switch format {
 	case FmtProtoDelim:
 		return &protoDecoder{r: r}
-	case fmtJSON2:
-		return newJSON2Decoder(r)
 	}
 	return &textDecoder{r: r}
 }
@@ -107,10 +87,32 @@ type protoDecoder struct {
 // Decode implements the Decoder interface.
 func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 	_, err := pbutil.ReadDelimited(d.r, v)
-	return err
+	if err != nil {
+		return err
+	}
+	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
+		return fmt.Errorf("invalid metric name %q", v.GetName())
+	}
+	for _, m := range v.GetMetric() {
+		if m == nil {
+			continue
+		}
+		for _, l := range m.GetLabel() {
+			if l == nil {
+				continue
+			}
+			if !model.LabelValue(l.GetValue()).IsValid() {
+				return fmt.Errorf("invalid label value %q", l.GetValue())
+			}
+			if !model.LabelName(l.GetName()).IsValid() {
+				return fmt.Errorf("invalid label name %q", l.GetName())
+			}
+		}
+	}
+	return nil
 }
 
-// textDecoder implements the Decoder interface for the text protcol.
+// textDecoder implements the Decoder interface for the text protocol.
 type textDecoder struct {
 	r    io.Reader
 	p    TextParser
@@ -141,6 +143,8 @@ func (d *textDecoder) Decode(v *dto.MetricFamily) error {
 	return nil
 }
 
+// SampleDecoder wraps a Decoder to extract samples from the metric families
+// decoded by the wrapped Decoder.
 type SampleDecoder struct {
 	Dec  Decoder
 	Opts *DecodeOptions
@@ -148,37 +152,51 @@ type SampleDecoder struct {
 	f dto.MetricFamily
 }
 
+// Decode calls the Decode method of the wrapped Decoder and then extracts the
+// samples from the decoded MetricFamily into the provided model.Vector.
 func (sd *SampleDecoder) Decode(s *model.Vector) error {
-	if err := sd.Dec.Decode(&sd.f); err != nil {
+	err := sd.Dec.Decode(&sd.f)
+	if err != nil {
 		return err
 	}
-	*s = extractSamples(&sd.f, sd.Opts)
-	return nil
+	*s, err = extractSamples(&sd.f, sd.Opts)
+	return err
 }
 
-// Extract samples builds a slice of samples from the provided metric families.
-func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) model.Vector {
-	var all model.Vector
+// ExtractSamples builds a slice of samples from the provided metric
+// families. If an error occurs during sample extraction, it continues to
+// extract from the remaining metric families. The returned error is the last
+// error that has occured.
+func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) (model.Vector, error) {
+	var (
+		all     model.Vector
+		lastErr error
+	)
 	for _, f := range fams {
-		all = append(all, extractSamples(f, o)...)
+		some, err := extractSamples(f, o)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		all = append(all, some...)
 	}
-	return all
+	return all, lastErr
 }
 
-func extractSamples(f *dto.MetricFamily, o *DecodeOptions) model.Vector {
+func extractSamples(f *dto.MetricFamily, o *DecodeOptions) (model.Vector, error) {
 	switch f.GetType() {
 	case dto.MetricType_COUNTER:
-		return extractCounter(o, f)
+		return extractCounter(o, f), nil
 	case dto.MetricType_GAUGE:
-		return extractGauge(o, f)
+		return extractGauge(o, f), nil
 	case dto.MetricType_SUMMARY:
-		return extractSummary(o, f)
+		return extractSummary(o, f), nil
 	case dto.MetricType_UNTYPED:
-		return extractUntyped(o, f)
+		return extractUntyped(o, f), nil
 	case dto.MetricType_HISTOGRAM:
-		return extractHistogram(o, f)
+		return extractHistogram(o, f), nil
 	}
-	panic("expfmt.extractSamples: unknown metric family type")
+	return nil, fmt.Errorf("expfmt.extractSamples: unknown metric family type %v", f.GetType())
 }
 
 func extractCounter(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
diff --git a/vendor/github.com/prometheus/common/expfmt/encode.go b/vendor/github.com/prometheus/common/expfmt/encode.go
index 392ca90e..11839ed6 100644
--- a/vendor/github.com/prometheus/common/expfmt/encode.go
+++ b/vendor/github.com/prometheus/common/expfmt/encode.go
@@ -18,9 +18,9 @@ import (
 	"io"
 	"net/http"
 
-	"bitbucket.org/ww/goautoneg"
 	"github.com/golang/protobuf/proto"
 	"github.com/matttproud/golang_protobuf_extensions/pbutil"
+	"github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg"
 
 	dto "github.com/prometheus/client_model/go"
 )
diff --git a/vendor/github.com/prometheus/common/expfmt/expfmt.go b/vendor/github.com/prometheus/common/expfmt/expfmt.go
index 366fbde9..371ac750 100644
--- a/vendor/github.com/prometheus/common/expfmt/expfmt.go
+++ b/vendor/github.com/prometheus/common/expfmt/expfmt.go
@@ -11,14 +11,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// A package for reading and writing Prometheus metrics.
+// Package expfmt contains tools for reading and writing Prometheus metrics.
 package expfmt
 
+// Format specifies the HTTP content type of the different wire protocols.
 type Format string
 
+// Constants to assemble the Content-Type values for the different wire protocols.
 const (
-	TextVersion = "0.0.4"
-
+	TextVersion   = "0.0.4"
 	ProtoType     = `application/vnd.google.protobuf`
 	ProtoProtocol = `io.prometheus.client.MetricFamily`
 	ProtoFmt      = ProtoType + "; proto=" + ProtoProtocol + ";"
@@ -29,9 +30,6 @@ const (
 	FmtProtoDelim   Format = ProtoFmt + ` encoding=delimited`
 	FmtProtoText    Format = ProtoFmt + ` encoding=text`
 	FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text`
-
-	// fmtJSON2 is hidden as it is deprecated.
-	fmtJSON2 Format = `application/json; version=0.0.2`
 )
 
 const (
diff --git a/vendor/github.com/prometheus/common/expfmt/fuzz.go b/vendor/github.com/prometheus/common/expfmt/fuzz.go
index 14f92014..dc2eedee 100644
--- a/vendor/github.com/prometheus/common/expfmt/fuzz.go
+++ b/vendor/github.com/prometheus/common/expfmt/fuzz.go
@@ -20,8 +20,8 @@ import "bytes"
 
 // Fuzz text metric parser with with github.com/dvyukov/go-fuzz:
 //
-//     go-fuzz-build github.com/prometheus/client_golang/text
-//     go-fuzz -bin text-fuzz.zip -workdir fuzz
+//     go-fuzz-build github.com/prometheus/common/expfmt
+//     go-fuzz -bin expfmt-fuzz.zip -workdir fuzz
 //
 // Further input samples should go in the folder fuzz/corpus.
 func Fuzz(in []byte) int {
diff --git a/vendor/github.com/prometheus/common/expfmt/json_decode.go b/vendor/github.com/prometheus/common/expfmt/json_decode.go
deleted file mode 100644
index 67e3a0d4..00000000
--- a/vendor/github.com/prometheus/common/expfmt/json_decode.go
+++ /dev/null
@@ -1,162 +0,0 @@
-// Copyright 2015 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package expfmt
-
-import (
-	"encoding/json"
-	"fmt"
-	"io"
-	"sort"
-
-	"github.com/golang/protobuf/proto"
-	dto "github.com/prometheus/client_model/go"
-
-	"github.com/prometheus/common/model"
-)
-
-type json2Decoder struct {
-	dec  *json.Decoder
-	fams []*dto.MetricFamily
-}
-
-func newJSON2Decoder(r io.Reader) Decoder {
-	return &json2Decoder{
-		dec: json.NewDecoder(r),
-	}
-}
-
-type histogram002 struct {
-	Labels model.LabelSet     `json:"labels"`
-	Values map[string]float64 `json:"value"`
-}
-
-type counter002 struct {
-	Labels model.LabelSet `json:"labels"`
-	Value  float64        `json:"value"`
-}
-
-func protoLabelSet(base, ext model.LabelSet) []*dto.LabelPair {
-	labels := base.Clone().Merge(ext)
-	delete(labels, model.MetricNameLabel)
-
-	names := make([]string, 0, len(labels))
-	for ln := range labels {
-		names = append(names, string(ln))
-	}
-	sort.Strings(names)
-
-	pairs := make([]*dto.LabelPair, 0, len(labels))
-
-	for _, ln := range names {
-		lv := labels[model.LabelName(ln)]
-
-		pairs = append(pairs, &dto.LabelPair{
-			Name:  proto.String(ln),
-			Value: proto.String(string(lv)),
-		})
-	}
-
-	return pairs
-}
-
-func (d *json2Decoder) more() error {
-	var entities []struct {
-		BaseLabels model.LabelSet `json:"baseLabels"`
-		Docstring  string         `json:"docstring"`
-		Metric     struct {
-			Type   string          `json:"type"`
-			Values json.RawMessage `json:"value"`
-		} `json:"metric"`
-	}
-
-	if err := d.dec.Decode(&entities); err != nil {
-		return err
-	}
-	for _, e := range entities {
-		f := &dto.MetricFamily{
-			Name:   proto.String(string(e.BaseLabels[model.MetricNameLabel])),
-			Help:   proto.String(e.Docstring),
-			Type:   dto.MetricType_UNTYPED.Enum(),
-			Metric: []*dto.Metric{},
-		}
-
-		d.fams = append(d.fams, f)
-
-		switch e.Metric.Type {
-		case "counter", "gauge":
-			var values []counter002
-
-			if err := json.Unmarshal(e.Metric.Values, &values); err != nil {
-				return fmt.Errorf("could not extract %s value: %s", e.Metric.Type, err)
-			}
-
-			for _, ctr := range values {
-				f.Metric = append(f.Metric, &dto.Metric{
-					Label: protoLabelSet(e.BaseLabels, ctr.Labels),
-					Untyped: &dto.Untyped{
-						Value: proto.Float64(ctr.Value),
-					},
-				})
-			}
-
-		case "histogram":
-			var values []histogram002
-
-			if err := json.Unmarshal(e.Metric.Values, &values); err != nil {
-				return fmt.Errorf("could not extract %s value: %s", e.Metric.Type, err)
-			}
-
-			for _, hist := range values {
-				quants := make([]string, 0, len(values))
-				for q := range hist.Values {
-					quants = append(quants, q)
-				}
-
-				sort.Strings(quants)
-
-				for _, q := range quants {
-					value := hist.Values[q]
-					// The correct label is "quantile" but to not break old expressions
-					// this remains "percentile"
-					hist.Labels["percentile"] = model.LabelValue(q)
-
-					f.Metric = append(f.Metric, &dto.Metric{
-						Label: protoLabelSet(e.BaseLabels, hist.Labels),
-						Untyped: &dto.Untyped{
-							Value: proto.Float64(value),
-						},
-					})
-				}
-			}
-
-		default:
-			return fmt.Errorf("unknown metric type %q", e.Metric.Type)
-		}
-	}
-	return nil
-}
-
-// Decode implements the Decoder interface.
-func (d *json2Decoder) Decode(v *dto.MetricFamily) error {
-	if len(d.fams) == 0 {
-		if err := d.more(); err != nil {
-			return err
-		}
-	}
-
-	*v = *d.fams[0]
-	d.fams = d.fams[1:]
-
-	return nil
-}
diff --git a/vendor/github.com/prometheus/common/expfmt/text_create.go b/vendor/github.com/prometheus/common/expfmt/text_create.go
index 0bb9c14c..f11321cd 100644
--- a/vendor/github.com/prometheus/common/expfmt/text_create.go
+++ b/vendor/github.com/prometheus/common/expfmt/text_create.go
@@ -14,7 +14,6 @@
 package expfmt
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"math"
@@ -26,9 +25,12 @@ import (
 
 // MetricFamilyToText converts a MetricFamily proto message into text format and
 // writes the resulting lines to 'out'. It returns the number of bytes written
-// and any error encountered.  This function does not perform checks on the
-// content of the metric and label names, i.e. invalid metric or label names
+// and any error encountered. The output will have the same order as the input,
+// no further sorting is performed. Furthermore, this function assumes the input
+// is already sanitized and does not perform any sanity checks. If the input
+// contains duplicate metrics or invalid metric or label names, the conversion
 // will result in invalid text format output.
+//
 // This method fulfills the type 'prometheus.encoder'.
 func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 	var written int
@@ -285,21 +287,17 @@ func labelPairsToText(
 	return written, nil
 }
 
+var (
+	escape                = strings.NewReplacer("\\", `\\`, "\n", `\n`)
+	escapeWithDoubleQuote = strings.NewReplacer("\\", `\\`, "\n", `\n`, "\"", `\"`)
+)
+
 // escapeString replaces '\' by '\\', new line character by '\n', and - if
 // includeDoubleQuote is true - '"' by '\"'.
 func escapeString(v string, includeDoubleQuote bool) string {
-	result := bytes.NewBuffer(make([]byte, 0, len(v)))
-	for _, c := range v {
-		switch {
-		case c == '\\':
-			result.WriteString(`\\`)
-		case includeDoubleQuote && c == '"':
-			result.WriteString(`\"`)
-		case c == '\n':
-			result.WriteString(`\n`)
-		default:
-			result.WriteRune(c)
-		}
+	if includeDoubleQuote {
+		return escapeWithDoubleQuote.Replace(v)
 	}
-	return result.String()
+
+	return escape.Replace(v)
 }
diff --git a/vendor/github.com/prometheus/common/expfmt/text_parse.go b/vendor/github.com/prometheus/common/expfmt/text_parse.go
index 84433bc4..ef9a1507 100644
--- a/vendor/github.com/prometheus/common/expfmt/text_parse.go
+++ b/vendor/github.com/prometheus/common/expfmt/text_parse.go
@@ -47,7 +47,7 @@ func (e ParseError) Error() string {
 }
 
 // TextParser is used to parse the simple and flat text-based exchange format. Its
-// nil value is ready to use.
+// zero value is ready to use.
 type TextParser struct {
 	metricFamiliesByName map[string]*dto.MetricFamily
 	buf                  *bufio.Reader // Where the parsed input is read through.
@@ -108,6 +108,13 @@ func (p *TextParser) TextToMetricFamilies(in io.Reader) (map[string]*dto.MetricF
 			delete(p.metricFamiliesByName, k)
 		}
 	}
+	// If p.err is io.EOF now, we have run into a premature end of the input
+	// stream. Turn this error into something nicer and more
+	// meaningful. (io.EOF is often used as a signal for the legitimate end
+	// of an input stream.)
+	if p.err == io.EOF {
+		p.parseError("unexpected end of input stream")
+	}
 	return p.metricFamiliesByName, p.err
 }
 
diff --git a/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt
new file mode 100644
index 00000000..7723656d
--- /dev/null
+++ b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt
@@ -0,0 +1,67 @@
+PACKAGE
+
+package goautoneg
+import "bitbucket.org/ww/goautoneg"
+
+HTTP Content-Type Autonegotiation.
+
+The functions in this package implement the behaviour specified in
+http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
+
+Copyright (c) 2011, Open Knowledge Foundation Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    Neither the name of the Open Knowledge Foundation Ltd. nor the
+    names of its contributors may be used to endorse or promote
+    products derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+FUNCTIONS
+
+func Negotiate(header string, alternatives []string) (content_type string)
+Negotiate the most appropriate content_type given the accept header
+and a list of alternatives.
+
+func ParseAccept(header string) (accept []Accept)
+Parse an Accept Header string returning a sorted list
+of clauses
+
+
+TYPES
+
+type Accept struct {
+    Type, SubType string
+    Q             float32
+    Params        map[string]string
+}
+Structure to represent a clause in an HTTP Accept Header
+
+
+SUBDIRECTORIES
+
+	.hg
diff --git a/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go
new file mode 100644
index 00000000..648b38cb
--- /dev/null
+++ b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go
@@ -0,0 +1,162 @@
+/*
+HTTP Content-Type Autonegotiation.
+
+The functions in this package implement the behaviour specified in
+http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
+
+Copyright (c) 2011, Open Knowledge Foundation Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    Neither the name of the Open Knowledge Foundation Ltd. nor the
+    names of its contributors may be used to endorse or promote
+    products derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+*/
+package goautoneg
+
+import (
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// Structure to represent a clause in an HTTP Accept Header
+type Accept struct {
+	Type, SubType string
+	Q             float64
+	Params        map[string]string
+}
+
+// For internal use, so that we can use the sort interface
+type accept_slice []Accept
+
+func (accept accept_slice) Len() int {
+	slice := []Accept(accept)
+	return len(slice)
+}
+
+func (accept accept_slice) Less(i, j int) bool {
+	slice := []Accept(accept)
+	ai, aj := slice[i], slice[j]
+	if ai.Q > aj.Q {
+		return true
+	}
+	if ai.Type != "*" && aj.Type == "*" {
+		return true
+	}
+	if ai.SubType != "*" && aj.SubType == "*" {
+		return true
+	}
+	return false
+}
+
+func (accept accept_slice) Swap(i, j int) {
+	slice := []Accept(accept)
+	slice[i], slice[j] = slice[j], slice[i]
+}
+
+// Parse an Accept Header string returning a sorted list
+// of clauses
+func ParseAccept(header string) (accept []Accept) {
+	parts := strings.Split(header, ",")
+	accept = make([]Accept, 0, len(parts))
+	for _, part := range parts {
+		part := strings.Trim(part, " ")
+
+		a := Accept{}
+		a.Params = make(map[string]string)
+		a.Q = 1.0
+
+		mrp := strings.Split(part, ";")
+
+		media_range := mrp[0]
+		sp := strings.Split(media_range, "/")
+		a.Type = strings.Trim(sp[0], " ")
+
+		switch {
+		case len(sp) == 1 && a.Type == "*":
+			a.SubType = "*"
+		case len(sp) == 2:
+			a.SubType = strings.Trim(sp[1], " ")
+		default:
+			continue
+		}
+
+		if len(mrp) == 1 {
+			accept = append(accept, a)
+			continue
+		}
+
+		for _, param := range mrp[1:] {
+			sp := strings.SplitN(param, "=", 2)
+			if len(sp) != 2 {
+				continue
+			}
+			token := strings.Trim(sp[0], " ")
+			if token == "q" {
+				a.Q, _ = strconv.ParseFloat(sp[1], 32)
+			} else {
+				a.Params[token] = strings.Trim(sp[1], " ")
+			}
+		}
+
+		accept = append(accept, a)
+	}
+
+	slice := accept_slice(accept)
+	sort.Sort(slice)
+
+	return
+}
+
+// Negotiate the most appropriate content_type given the accept header
+// and a list of alternatives.
+func Negotiate(header string, alternatives []string) (content_type string) {
+	asp := make([][]string, 0, len(alternatives))
+	for _, ctype := range alternatives {
+		asp = append(asp, strings.SplitN(ctype, "/", 2))
+	}
+	for _, clause := range ParseAccept(header) {
+		for i, ctsp := range asp {
+			if clause.Type == ctsp[0] && clause.SubType == ctsp[1] {
+				content_type = alternatives[i]
+				return
+			}
+			if clause.Type == ctsp[0] && clause.SubType == "*" {
+				content_type = alternatives[i]
+				return
+			}
+			if clause.Type == "*" && clause.SubType == "*" {
+				content_type = alternatives[i]
+				return
+			}
+		}
+	}
+	return
+}
diff --git a/vendor/github.com/prometheus/common/model/alert.go b/vendor/github.com/prometheus/common/model/alert.go
index b027e9f3..35e739c7 100644
--- a/vendor/github.com/prometheus/common/model/alert.go
+++ b/vendor/github.com/prometheus/common/model/alert.go
@@ -35,8 +35,9 @@ type Alert struct {
 	Annotations LabelSet `json:"annotations"`
 
 	// The known time range for this alert. Both ends are optional.
-	StartsAt time.Time `json:"startsAt,omitempty"`
-	EndsAt   time.Time `json:"endsAt,omitempty"`
+	StartsAt     time.Time `json:"startsAt,omitempty"`
+	EndsAt       time.Time `json:"endsAt,omitempty"`
+	GeneratorURL string    `json:"generatorURL"`
 }
 
 // Name returns the name of the alert. It is equivalent to the "alertname" label.
@@ -60,10 +61,16 @@ func (a *Alert) String() string {
 
 // Resolved returns true iff the activity interval ended in the past.
 func (a *Alert) Resolved() bool {
+	return a.ResolvedAt(time.Now())
+}
+
+// ResolvedAt returns true off the activity interval ended before
+// the given timestamp.
+func (a *Alert) ResolvedAt(ts time.Time) bool {
 	if a.EndsAt.IsZero() {
 		return false
 	}
-	return !a.EndsAt.After(time.Now())
+	return !a.EndsAt.After(ts)
 }
 
 // Status returns the status of the alert.
@@ -74,6 +81,26 @@ func (a *Alert) Status() AlertStatus {
 	return AlertFiring
 }
 
+// Validate checks whether the alert data is inconsistent.
+func (a *Alert) Validate() error {
+	if a.StartsAt.IsZero() {
+		return fmt.Errorf("start time missing")
+	}
+	if !a.EndsAt.IsZero() && a.EndsAt.Before(a.StartsAt) {
+		return fmt.Errorf("start time must be before end time")
+	}
+	if err := a.Labels.Validate(); err != nil {
+		return fmt.Errorf("invalid label set: %s", err)
+	}
+	if len(a.Labels) == 0 {
+		return fmt.Errorf("at least one label pair required")
+	}
+	if err := a.Annotations.Validate(); err != nil {
+		return fmt.Errorf("invalid annotations: %s", err)
+	}
+	return nil
+}
+
 // Alert is a list of alerts that can be sorted in chronological order.
 type Alerts []*Alert
 
diff --git a/vendor/github.com/prometheus/common/model/fnv.go b/vendor/github.com/prometheus/common/model/fnv.go
new file mode 100644
index 00000000..038fc1c9
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/fnv.go
@@ -0,0 +1,42 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}
diff --git a/vendor/github.com/prometheus/common/model/labels.go b/vendor/github.com/prometheus/common/model/labels.go
index 6459c8f7..41051a01 100644
--- a/vendor/github.com/prometheus/common/model/labels.go
+++ b/vendor/github.com/prometheus/common/model/labels.go
@@ -17,8 +17,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"regexp"
-	"sort"
 	"strings"
+	"unicode/utf8"
 )
 
 const (
@@ -80,20 +80,37 @@ const (
 	QuantileLabel = "quantile"
 )
 
-// LabelNameRE is a regular expression matching valid label names.
+// LabelNameRE is a regular expression matching valid label names. Note that the
+// IsValid method of LabelName performs the same check but faster than a match
+// with this regular expression.
 var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
 
 // A LabelName is a key for a LabelSet or Metric.  It has a value associated
 // therewith.
 type LabelName string
 
+// IsValid is true iff the label name matches the pattern of LabelNameRE. This
+// method, however, does not use LabelNameRE for the check but a much faster
+// hardcoded implementation.
+func (ln LabelName) IsValid() bool {
+	if len(ln) == 0 {
+		return false
+	}
+	for i, b := range ln {
+		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) {
+			return false
+		}
+	}
+	return true
+}
+
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
 func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	var s string
 	if err := unmarshal(&s); err != nil {
 		return err
 	}
-	if !LabelNameRE.MatchString(s) {
+	if !LabelName(s).IsValid() {
 		return fmt.Errorf("%q is not a valid label name", s)
 	}
 	*ln = LabelName(s)
@@ -106,7 +123,7 @@ func (ln *LabelName) UnmarshalJSON(b []byte) error {
 	if err := json.Unmarshal(b, &s); err != nil {
 		return err
 	}
-	if !LabelNameRE.MatchString(s) {
+	if !LabelName(s).IsValid() {
 		return fmt.Errorf("%q is not a valid label name", s)
 	}
 	*ln = LabelName(s)
@@ -139,6 +156,11 @@ func (l LabelNames) String() string {
 // A LabelValue is an associated value for a LabelName.
 type LabelValue string
 
+// IsValid returns true iff the string is a valid UTF8.
+func (lv LabelValue) IsValid() bool {
+	return utf8.ValidString(string(lv))
+}
+
 // LabelValues is a sortable LabelValue slice. It implements sort.Interface.
 type LabelValues []LabelValue
 
@@ -147,7 +169,7 @@ func (l LabelValues) Len() int {
 }
 
 func (l LabelValues) Less(i, j int) bool {
-	return sort.StringsAreSorted([]string{string(l[i]), string(l[j])})
+	return string(l[i]) < string(l[j])
 }
 
 func (l LabelValues) Swap(i, j int) {
diff --git a/vendor/github.com/prometheus/common/model/labelset.go b/vendor/github.com/prometheus/common/model/labelset.go
index 142b9d1e..6eda08a7 100644
--- a/vendor/github.com/prometheus/common/model/labelset.go
+++ b/vendor/github.com/prometheus/common/model/labelset.go
@@ -27,6 +27,21 @@ import (
 // match.
 type LabelSet map[LabelName]LabelValue
 
+// Validate checks whether all names and values in the label set
+// are valid.
+func (ls LabelSet) Validate() error {
+	for ln, lv := range ls {
+		if !ln.IsValid() {
+			return fmt.Errorf("invalid name %q", ln)
+		}
+		if !lv.IsValid() {
+			return fmt.Errorf("invalid value %q", lv)
+		}
+	}
+	return nil
+}
+
+// Equal returns true iff both label sets have exactly the same key/value pairs.
 func (ls LabelSet) Equal(o LabelSet) bool {
 	if len(ls) != len(o) {
 		return false
@@ -90,6 +105,7 @@ func (ls LabelSet) Before(o LabelSet) bool {
 	return false
 }
 
+// Clone returns a copy of the label set.
 func (ls LabelSet) Clone() LabelSet {
 	lsn := make(LabelSet, len(ls))
 	for ln, lv := range ls {
@@ -144,7 +160,7 @@ func (l *LabelSet) UnmarshalJSON(b []byte) error {
 	// LabelName as a string and does not call its UnmarshalJSON method.
 	// Thus, we have to replicate the behavior here.
 	for ln := range m {
-		if !LabelNameRE.MatchString(string(ln)) {
+		if !ln.IsValid() {
 			return fmt.Errorf("%q is not a valid label name", ln)
 		}
 	}
diff --git a/vendor/github.com/prometheus/common/model/metric.go b/vendor/github.com/prometheus/common/model/metric.go
index 25fc3c94..f7250909 100644
--- a/vendor/github.com/prometheus/common/model/metric.go
+++ b/vendor/github.com/prometheus/common/model/metric.go
@@ -15,11 +15,18 @@ package model
 
 import (
 	"fmt"
+	"regexp"
 	"sort"
 	"strings"
 )
 
-var separator = []byte{0}
+var (
+	separator = []byte{0}
+	// MetricNameRE is a regular expression matching valid metric
+	// names. Note that the IsValidMetricName function performs the same
+	// check but faster than a match with this regular expression.
+	MetricNameRE = regexp.MustCompile(`^[a-zA-Z_:][a-zA-Z0-9_:]*$`)
+)
 
 // A Metric is similar to a LabelSet, but the key difference is that a Metric is
 // a singleton and refers to one and only one stream of samples.
@@ -37,7 +44,7 @@ func (m Metric) Before(o Metric) bool {
 
 // Clone returns a copy of the Metric.
 func (m Metric) Clone() Metric {
-	clone := Metric{}
+	clone := make(Metric, len(m))
 	for k, v := range m {
 		clone[k] = v
 	}
@@ -79,3 +86,18 @@ func (m Metric) Fingerprint() Fingerprint {
 func (m Metric) FastFingerprint() Fingerprint {
 	return LabelSet(m).FastFingerprint()
 }
+
+// IsValidMetricName returns true iff name matches the pattern of MetricNameRE.
+// This function, however, does not use MetricNameRE for the check but a much
+// faster hardcoded implementation.
+func IsValidMetricName(n LabelValue) bool {
+	if len(n) == 0 {
+		return false
+	}
+	for i, b := range n {
+		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || b == ':' || (b >= '0' && b <= '9' && i > 0)) {
+			return false
+		}
+	}
+	return true
+}
diff --git a/vendor/github.com/prometheus/common/model/model.go b/vendor/github.com/prometheus/common/model/model.go
index 88f013a4..a7b96917 100644
--- a/vendor/github.com/prometheus/common/model/model.go
+++ b/vendor/github.com/prometheus/common/model/model.go
@@ -12,5 +12,5 @@
 // limitations under the License.
 
 // Package model contains common data structures that are shared across
-// Prometheus componenets and libraries.
+// Prometheus components and libraries.
 package model
diff --git a/vendor/github.com/prometheus/common/model/signature.go b/vendor/github.com/prometheus/common/model/signature.go
index 28f37006..8762b13c 100644
--- a/vendor/github.com/prometheus/common/model/signature.go
+++ b/vendor/github.com/prometheus/common/model/signature.go
@@ -14,11 +14,7 @@
 package model
 
 import (
-	"bytes"
-	"hash"
-	"hash/fnv"
 	"sort"
-	"sync"
 )
 
 // SeparatorByte is a byte that cannot occur in valid UTF-8 sequences and is
@@ -28,30 +24,9 @@ const SeparatorByte byte = 255
 
 var (
 	// cache the signature of an empty label set.
-	emptyLabelSignature = fnv.New64a().Sum64()
-
-	hashAndBufPool sync.Pool
+	emptyLabelSignature = hashNew()
 )
 
-type hashAndBuf struct {
-	h hash.Hash64
-	b bytes.Buffer
-}
-
-func getHashAndBuf() *hashAndBuf {
-	hb := hashAndBufPool.Get()
-	if hb == nil {
-		return &hashAndBuf{h: fnv.New64a()}
-	}
-	return hb.(*hashAndBuf)
-}
-
-func putHashAndBuf(hb *hashAndBuf) {
-	hb.h.Reset()
-	hb.b.Reset()
-	hashAndBufPool.Put(hb)
-}
-
 // LabelsToSignature returns a quasi-unique signature (i.e., fingerprint) for a
 // given label set. (Collisions are possible but unlikely if the number of label
 // sets the function is applied to is small.)
@@ -66,18 +41,14 @@ func LabelsToSignature(labels map[string]string) uint64 {
 	}
 	sort.Strings(labelNames)
 
-	hb := getHashAndBuf()
-	defer putHashAndBuf(hb)
-
+	sum := hashNew()
 	for _, labelName := range labelNames {
-		hb.b.WriteString(labelName)
-		hb.b.WriteByte(SeparatorByte)
-		hb.b.WriteString(labels[labelName])
-		hb.b.WriteByte(SeparatorByte)
-		hb.h.Write(hb.b.Bytes())
-		hb.b.Reset()
+		sum = hashAdd(sum, labelName)
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, labels[labelName])
+		sum = hashAddByte(sum, SeparatorByte)
 	}
-	return hb.h.Sum64()
+	return sum
 }
 
 // labelSetToFingerprint works exactly as LabelsToSignature but takes a LabelSet as
@@ -93,18 +64,14 @@ func labelSetToFingerprint(ls LabelSet) Fingerprint {
 	}
 	sort.Sort(labelNames)
 
-	hb := getHashAndBuf()
-	defer putHashAndBuf(hb)
-
+	sum := hashNew()
 	for _, labelName := range labelNames {
-		hb.b.WriteString(string(labelName))
-		hb.b.WriteByte(SeparatorByte)
-		hb.b.WriteString(string(ls[labelName]))
-		hb.b.WriteByte(SeparatorByte)
-		hb.h.Write(hb.b.Bytes())
-		hb.b.Reset()
+		sum = hashAdd(sum, string(labelName))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(ls[labelName]))
+		sum = hashAddByte(sum, SeparatorByte)
 	}
-	return Fingerprint(hb.h.Sum64())
+	return Fingerprint(sum)
 }
 
 // labelSetToFastFingerprint works similar to labelSetToFingerprint but uses a
@@ -116,17 +83,12 @@ func labelSetToFastFingerprint(ls LabelSet) Fingerprint {
 	}
 
 	var result uint64
-	hb := getHashAndBuf()
-	defer putHashAndBuf(hb)
-
 	for labelName, labelValue := range ls {
-		hb.b.WriteString(string(labelName))
-		hb.b.WriteByte(SeparatorByte)
-		hb.b.WriteString(string(labelValue))
-		hb.h.Write(hb.b.Bytes())
-		result ^= hb.h.Sum64()
-		hb.h.Reset()
-		hb.b.Reset()
+		sum := hashNew()
+		sum = hashAdd(sum, string(labelName))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(labelValue))
+		result ^= sum
 	}
 	return Fingerprint(result)
 }
@@ -136,24 +98,20 @@ func labelSetToFastFingerprint(ls LabelSet) Fingerprint {
 // specified LabelNames into the signature calculation. The labels passed in
 // will be sorted by this function.
 func SignatureForLabels(m Metric, labels ...LabelName) uint64 {
-	if len(m) == 0 || len(labels) == 0 {
+	if len(labels) == 0 {
 		return emptyLabelSignature
 	}
 
 	sort.Sort(LabelNames(labels))
 
-	hb := getHashAndBuf()
-	defer putHashAndBuf(hb)
-
+	sum := hashNew()
 	for _, label := range labels {
-		hb.b.WriteString(string(label))
-		hb.b.WriteByte(SeparatorByte)
-		hb.b.WriteString(string(m[label]))
-		hb.b.WriteByte(SeparatorByte)
-		hb.h.Write(hb.b.Bytes())
-		hb.b.Reset()
+		sum = hashAdd(sum, string(label))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(m[label]))
+		sum = hashAddByte(sum, SeparatorByte)
 	}
-	return hb.h.Sum64()
+	return sum
 }
 
 // SignatureWithoutLabels works like LabelsToSignature but takes a Metric as
@@ -175,16 +133,12 @@ func SignatureWithoutLabels(m Metric, labels map[LabelName]struct{}) uint64 {
 	}
 	sort.Sort(labelNames)
 
-	hb := getHashAndBuf()
-	defer putHashAndBuf(hb)
-
+	sum := hashNew()
 	for _, labelName := range labelNames {
-		hb.b.WriteString(string(labelName))
-		hb.b.WriteByte(SeparatorByte)
-		hb.b.WriteString(string(m[labelName]))
-		hb.b.WriteByte(SeparatorByte)
-		hb.h.Write(hb.b.Bytes())
-		hb.b.Reset()
+		sum = hashAdd(sum, string(labelName))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(m[labelName]))
+		sum = hashAddByte(sum, SeparatorByte)
 	}
-	return hb.h.Sum64()
+	return sum
 }
diff --git a/vendor/github.com/prometheus/common/model/silence.go b/vendor/github.com/prometheus/common/model/silence.go
index b4b96eae..7538e299 100644
--- a/vendor/github.com/prometheus/common/model/silence.go
+++ b/vendor/github.com/prometheus/common/model/silence.go
@@ -44,6 +44,21 @@ func (m *Matcher) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+// Validate returns true iff all fields of the matcher have valid values.
+func (m *Matcher) Validate() error {
+	if !m.Name.IsValid() {
+		return fmt.Errorf("invalid name %q", m.Name)
+	}
+	if m.IsRegex {
+		if _, err := regexp.Compile(m.Value); err != nil {
+			return fmt.Errorf("invalid regular expression %q", m.Value)
+		}
+	} else if !LabelValue(m.Value).IsValid() || len(m.Value) == 0 {
+		return fmt.Errorf("invalid value %q", m.Value)
+	}
+	return nil
+}
+
 // Silence defines the representation of a silence definiton
 // in the Prometheus eco-system.
 type Silence struct {
@@ -58,3 +73,34 @@ type Silence struct {
 	CreatedBy string    `json:"createdBy"`
 	Comment   string    `json:"comment,omitempty"`
 }
+
+// Validate returns true iff all fields of the silence have valid values.
+func (s *Silence) Validate() error {
+	if len(s.Matchers) == 0 {
+		return fmt.Errorf("at least one matcher required")
+	}
+	for _, m := range s.Matchers {
+		if err := m.Validate(); err != nil {
+			return fmt.Errorf("invalid matcher: %s", err)
+		}
+	}
+	if s.StartsAt.IsZero() {
+		return fmt.Errorf("start time missing")
+	}
+	if s.EndsAt.IsZero() {
+		return fmt.Errorf("end time missing")
+	}
+	if s.EndsAt.Before(s.StartsAt) {
+		return fmt.Errorf("start time must be before end time")
+	}
+	if s.CreatedBy == "" {
+		return fmt.Errorf("creator information missing")
+	}
+	if s.Comment == "" {
+		return fmt.Errorf("comment missing")
+	}
+	if s.CreatedAt.IsZero() {
+		return fmt.Errorf("creation timestamp missing")
+	}
+	return nil
+}
diff --git a/vendor/github.com/prometheus/common/model/time.go b/vendor/github.com/prometheus/common/model/time.go
index ebc8bf6c..548968ae 100644
--- a/vendor/github.com/prometheus/common/model/time.go
+++ b/vendor/github.com/prometheus/common/model/time.go
@@ -163,51 +163,70 @@ func (t *Time) UnmarshalJSON(b []byte) error {
 // This type should not propagate beyond the scope of input/output processing.
 type Duration time.Duration
 
+var durationRE = regexp.MustCompile("^([0-9]+)(y|w|d|h|m|s|ms)$")
+
 // StringToDuration parses a string into a time.Duration, assuming that a year
-// a day always has 24h.
+// always has 365d, a week always has 7d, and a day always has 24h.
 func ParseDuration(durationStr string) (Duration, error) {
 	matches := durationRE.FindStringSubmatch(durationStr)
 	if len(matches) != 3 {
 		return 0, fmt.Errorf("not a valid duration string: %q", durationStr)
 	}
-	durSeconds, _ := strconv.Atoi(matches[1])
-	dur := time.Duration(durSeconds) * time.Second
-	unit := matches[2]
-	switch unit {
+	var (
+		n, _ = strconv.Atoi(matches[1])
+		dur  = time.Duration(n) * time.Millisecond
+	)
+	switch unit := matches[2]; unit {
+	case "y":
+		dur *= 1000 * 60 * 60 * 24 * 365
+	case "w":
+		dur *= 1000 * 60 * 60 * 24 * 7
 	case "d":
-		dur *= 60 * 60 * 24
+		dur *= 1000 * 60 * 60 * 24
 	case "h":
-		dur *= 60 * 60
+		dur *= 1000 * 60 * 60
 	case "m":
-		dur *= 60
+		dur *= 1000 * 60
 	case "s":
-		dur *= 1
+		dur *= 1000
+	case "ms":
+		// Value already correct
 	default:
 		return 0, fmt.Errorf("invalid time unit in duration string: %q", unit)
 	}
 	return Duration(dur), nil
 }
 
-var durationRE = regexp.MustCompile("^([0-9]+)([ywdhms]+)$")
-
 func (d Duration) String() string {
-	seconds := int64(time.Duration(d) / time.Second)
+	var (
+		ms   = int64(time.Duration(d) / time.Millisecond)
+		unit = "ms"
+	)
 	factors := map[string]int64{
-		"d": 60 * 60 * 24,
-		"h": 60 * 60,
-		"m": 60,
-		"s": 1,
+		"y":  1000 * 60 * 60 * 24 * 365,
+		"w":  1000 * 60 * 60 * 24 * 7,
+		"d":  1000 * 60 * 60 * 24,
+		"h":  1000 * 60 * 60,
+		"m":  1000 * 60,
+		"s":  1000,
+		"ms": 1,
 	}
-	unit := "s"
+
 	switch int64(0) {
-	case seconds % factors["d"]:
+	case ms % factors["y"]:
+		unit = "y"
+	case ms % factors["w"]:
+		unit = "w"
+	case ms % factors["d"]:
 		unit = "d"
-	case seconds % factors["h"]:
+	case ms % factors["h"]:
 		unit = "h"
-	case seconds % factors["m"]:
+	case ms % factors["m"]:
 		unit = "m"
+	case ms % factors["s"]:
+		unit = "s"
 	}
-	return fmt.Sprintf("%v%v", seconds/factors[unit], unit)
+	return fmt.Sprintf("%v%v", ms/factors[unit], unit)
 }
 
 // MarshalYAML implements the yaml.Marshaler interface.
diff --git a/vendor/github.com/prometheus/common/model/value.go b/vendor/github.com/prometheus/common/model/value.go
index 10ffb0bd..c9ed3ffd 100644
--- a/vendor/github.com/prometheus/common/model/value.go
+++ b/vendor/github.com/prometheus/common/model/value.go
@@ -16,11 +16,28 @@ package model
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"sort"
 	"strconv"
 	"strings"
 )
 
+var (
+	// ZeroSamplePair is the pseudo zero-value of SamplePair used to signal a
+	// non-existing sample pair. It is a SamplePair with timestamp Earliest and
+	// value 0.0. Note that the natural zero value of SamplePair has a timestamp
+	// of 0, which is possible to appear in a real SamplePair and thus not
+	// suitable to signal a non-existing SamplePair.
+	ZeroSamplePair = SamplePair{Timestamp: Earliest}
+
+	// ZeroSample is the pseudo zero-value of Sample used to signal a
+	// non-existing sample. It is a Sample with timestamp Earliest, value 0.0,
+	// and metric nil. Note that the natural zero value of Sample has a timestamp
+	// of 0, which is possible to appear in a real Sample and thus not suitable
+	// to signal a non-existing Sample.
+	ZeroSample = Sample{Timestamp: Earliest}
+)
+
 // A SampleValue is a representation of a value for a given sample at a given
 // time.
 type SampleValue float64
@@ -43,8 +60,14 @@ func (v *SampleValue) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+// Equal returns true if the value of v and o is equal or if both are NaN. Note
+// that v==o is false if both are NaN. If you want the conventional float
+// behavior, use == to compare two SampleValues.
 func (v SampleValue) Equal(o SampleValue) bool {
-	return v == o
+	if v == o {
+		return true
+	}
+	return math.IsNaN(float64(v)) && math.IsNaN(float64(o))
 }
 
 func (v SampleValue) String() string {
@@ -77,9 +100,9 @@ func (s *SamplePair) UnmarshalJSON(b []byte) error {
 }
 
 // Equal returns true if this SamplePair and o have equal Values and equal
-// Timestamps.
+// Timestamps. The sematics of Value equality is defined by SampleValue.Equal.
 func (s *SamplePair) Equal(o *SamplePair) bool {
-	return s == o || (s.Value == o.Value && s.Timestamp.Equal(o.Timestamp))
+	return s == o || (s.Value.Equal(o.Value) && s.Timestamp.Equal(o.Timestamp))
 }
 
 func (s SamplePair) String() string {
@@ -93,7 +116,8 @@ type Sample struct {
 	Timestamp Time        `json:"timestamp"`
 }
 
-// Equal compares first the metrics, then the timestamp, then the value.
+// Equal compares first the metrics, then the timestamp, then the value. The
+// sematics of value equality is defined by SampleValue.Equal.
 func (s *Sample) Equal(o *Sample) bool {
 	if s == o {
 		return true
@@ -105,11 +129,8 @@ func (s *Sample) Equal(o *Sample) bool {
 	if !s.Timestamp.Equal(o.Timestamp) {
 		return false
 	}
-	if s.Value != o.Value {
-		return false
-	}
 
-	return true
+	return s.Value.Equal(o.Value)
 }
 
 func (s Sample) String() string {
diff --git a/vendor/github.com/prometheus/procfs/.travis.yml b/vendor/github.com/prometheus/procfs/.travis.yml
new file mode 100644
index 00000000..a9e28bf5
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/.travis.yml
@@ -0,0 +1,5 @@
+sudo: false
+language: go
+go:
+    - 1.6.4
+    - 1.7.4
diff --git a/vendor/github.com/prometheus/procfs/AUTHORS.md b/vendor/github.com/prometheus/procfs/AUTHORS.md
deleted file mode 100644
index 6eb1935c..00000000
--- a/vendor/github.com/prometheus/procfs/AUTHORS.md
+++ /dev/null
@@ -1,11 +0,0 @@
-The Prometheus project was started by Matt T. Proud (emeritus) and
-Julius Volz in 2012.
-
-Maintainers of this repository:
-
-* Tobias Schmidt <ts@soundcloud.com>
-
-The following individuals have contributed code to this repository
-(listed in alphabetical order):
-
-* Tobias Schmidt <ts@soundcloud.com>
diff --git a/vendor/github.com/prometheus/procfs/CONTRIBUTING.md b/vendor/github.com/prometheus/procfs/CONTRIBUTING.md
index 5705f0fb..40503edb 100644
--- a/vendor/github.com/prometheus/procfs/CONTRIBUTING.md
+++ b/vendor/github.com/prometheus/procfs/CONTRIBUTING.md
@@ -2,9 +2,9 @@
 
 Prometheus uses GitHub to manage reviews of pull requests.
 
-* If you have a trivial fix or improvement, go ahead and create a pull
-  request, addressing (with `@...`) one or more of the maintainers
-  (see [AUTHORS.md](AUTHORS.md)) in the description of the pull request.
+* If you have a trivial fix or improvement, go ahead and create a pull request,
+  addressing (with `@...`) the maintainer of this repository (see
+  [MAINTAINERS.md](MAINTAINERS.md)) in the description of the pull request.
 
 * If you plan to do something more involved, first discuss your ideas
   on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/prometheus-developers).
diff --git a/vendor/github.com/prometheus/procfs/MAINTAINERS.md b/vendor/github.com/prometheus/procfs/MAINTAINERS.md
new file mode 100644
index 00000000..35993c41
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/MAINTAINERS.md
@@ -0,0 +1 @@
+* Tobias Schmidt <tobidt@gmail.com>
diff --git a/vendor/github.com/prometheus/procfs/Makefile b/vendor/github.com/prometheus/procfs/Makefile
new file mode 100644
index 00000000..c264a49d
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/Makefile
@@ -0,0 +1,6 @@
+ci:
+	! gofmt -l *.go | read nothing
+	go vet
+	go test -v ./...
+	go get github.com/golang/lint/golint
+	golint *.go
diff --git a/vendor/github.com/prometheus/procfs/README.md b/vendor/github.com/prometheus/procfs/README.md
index 0edf4966..20954947 100644
--- a/vendor/github.com/prometheus/procfs/README.md
+++ b/vendor/github.com/prometheus/procfs/README.md
@@ -3,9 +3,9 @@
 This procfs package provides functions to retrieve system, kernel and process
 metrics from the pseudo-filesystem proc.
 
+*WARNING*: This package is a work in progress. Its API may still break in
+backwards-incompatible ways without warnings. Use it at your own risk.
+
 [![GoDoc](https://godoc.org/github.com/prometheus/procfs?status.png)](https://godoc.org/github.com/prometheus/procfs)
-[![Circle CI](https://circleci.com/gh/prometheus/procfs.svg?style=svg)](https://circleci.com/gh/prometheus/procfs)
-
-# Testing
-
-    $ go test
+[![Build Status](https://travis-ci.org/prometheus/procfs.svg?branch=master)](https://travis-ci.org/prometheus/procfs)
+[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/procfs)](https://goreportcard.com/report/github.com/prometheus/procfs)
diff --git a/vendor/github.com/prometheus/procfs/buddyinfo.go b/vendor/github.com/prometheus/procfs/buddyinfo.go
new file mode 100644
index 00000000..680a9842
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/buddyinfo.go
@@ -0,0 +1,95 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// A BuddyInfo is the details parsed from /proc/buddyinfo.
+// The data is comprised of an array of free fragments of each size.
+// The sizes are 2^n*PAGE_SIZE, where n is the array index.
+type BuddyInfo struct {
+	Node  string
+	Zone  string
+	Sizes []float64
+}
+
+// NewBuddyInfo reads the buddyinfo statistics.
+func NewBuddyInfo() ([]BuddyInfo, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return nil, err
+	}
+
+	return fs.NewBuddyInfo()
+}
+
+// NewBuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
+func (fs FS) NewBuddyInfo() ([]BuddyInfo, error) {
+	file, err := os.Open(fs.Path("buddyinfo"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseBuddyInfo(file)
+}
+
+func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
+	var (
+		buddyInfo   = []BuddyInfo{}
+		scanner     = bufio.NewScanner(r)
+		bucketCount = -1
+	)
+
+	for scanner.Scan() {
+		var err error
+		line := scanner.Text()
+		parts := strings.Fields(string(line))
+
+		if len(parts) < 4 {
+			return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")
+		}
+
+		node := strings.TrimRight(parts[1], ",")
+		zone := strings.TrimRight(parts[3], ",")
+		arraySize := len(parts[4:])
+
+		if bucketCount == -1 {
+			bucketCount = arraySize
+		} else {
+			if bucketCount != arraySize {
+				return nil, fmt.Errorf("mismatch in number of buddyinfo buckets, previous count %d, new count %d", bucketCount, arraySize)
+			}
+		}
+
+		sizes := make([]float64, arraySize)
+		for i := 0; i < arraySize; i++ {
+			sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
+			if err != nil {
+				return nil, fmt.Errorf("invalid value in buddyinfo: %s", err)
+			}
+		}
+
+		buddyInfo = append(buddyInfo, BuddyInfo{node, zone, sizes})
+	}
+
+	return buddyInfo, scanner.Err()
+}
diff --git a/vendor/github.com/prometheus/procfs/fs.go b/vendor/github.com/prometheus/procfs/fs.go
index 838474ab..17546756 100644
--- a/vendor/github.com/prometheus/procfs/fs.go
+++ b/vendor/github.com/prometheus/procfs/fs.go
@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"path"
+
+	"github.com/prometheus/procfs/xfs"
 )
 
 // FS represents the pseudo-filesystem proc, which provides an interface to
@@ -27,10 +29,18 @@ func NewFS(mountPoint string) (FS, error) {
 	return FS(mountPoint), nil
 }
 
-func (fs FS) stat(p string) (os.FileInfo, error) {
-	return os.Stat(path.Join(string(fs), p))
+// Path returns the path of the given subsystem relative to the procfs root.
+func (fs FS) Path(p ...string) string {
+	return path.Join(append([]string{string(fs)}, p...)...)
 }
 
-func (fs FS) open(p string) (*os.File, error) {
-	return os.Open(path.Join(string(fs), p))
+// XFSStats retrieves XFS filesystem runtime statistics.
+func (fs FS) XFSStats() (*xfs.Stats, error) {
+	f, err := os.Open(fs.Path("fs/xfs/stat"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return xfs.ParseStats(f)
 }
diff --git a/vendor/github.com/prometheus/procfs/ipvs.go b/vendor/github.com/prometheus/procfs/ipvs.go
new file mode 100644
index 00000000..e7012f73
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/ipvs.go
@@ -0,0 +1,224 @@
+package procfs
+
+import (
+	"bufio"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// IPVSStats holds IPVS statistics, as exposed by the kernel in `/proc/net/ip_vs_stats`.
+type IPVSStats struct {
+	// Total count of connections.
+	Connections uint64
+	// Total incoming packages processed.
+	IncomingPackets uint64
+	// Total outgoing packages processed.
+	OutgoingPackets uint64
+	// Total incoming traffic.
+	IncomingBytes uint64
+	// Total outgoing traffic.
+	OutgoingBytes uint64
+}
+
+// IPVSBackendStatus holds current metrics of one virtual / real address pair.
+type IPVSBackendStatus struct {
+	// The local (virtual) IP address.
+	LocalAddress net.IP
+	// The local (virtual) port.
+	LocalPort uint16
+	// The transport protocol (TCP, UDP).
+	Proto string
+	// The remote (real) IP address.
+	RemoteAddress net.IP
+	// The remote (real) port.
+	RemotePort uint16
+	// The current number of active connections for this virtual/real address pair.
+	ActiveConn uint64
+	// The current number of inactive connections for this virtual/real address pair.
+	InactConn uint64
+	// The current weight of this virtual/real address pair.
+	Weight uint64
+}
+
+// NewIPVSStats reads the IPVS statistics.
+func NewIPVSStats() (IPVSStats, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+
+	return fs.NewIPVSStats()
+}
+
+// NewIPVSStats reads the IPVS statistics from the specified `proc` filesystem.
+func (fs FS) NewIPVSStats() (IPVSStats, error) {
+	file, err := os.Open(fs.Path("net/ip_vs_stats"))
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	defer file.Close()
+
+	return parseIPVSStats(file)
+}
+
+// parseIPVSStats performs the actual parsing of `ip_vs_stats`.
+func parseIPVSStats(file io.Reader) (IPVSStats, error) {
+	var (
+		statContent []byte
+		statLines   []string
+		statFields  []string
+		stats       IPVSStats
+	)
+
+	statContent, err := ioutil.ReadAll(file)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+
+	statLines = strings.SplitN(string(statContent), "\n", 4)
+	if len(statLines) != 4 {
+		return IPVSStats{}, errors.New("ip_vs_stats corrupt: too short")
+	}
+
+	statFields = strings.Fields(statLines[2])
+	if len(statFields) != 5 {
+		return IPVSStats{}, errors.New("ip_vs_stats corrupt: unexpected number of fields")
+	}
+
+	stats.Connections, err = strconv.ParseUint(statFields[0], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.IncomingPackets, err = strconv.ParseUint(statFields[1], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.OutgoingPackets, err = strconv.ParseUint(statFields[2], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.IncomingBytes, err = strconv.ParseUint(statFields[3], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.OutgoingBytes, err = strconv.ParseUint(statFields[4], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+
+	return stats, nil
+}
+
+// NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs.
+func NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return []IPVSBackendStatus{}, err
+	}
+
+	return fs.NewIPVSBackendStatus()
+}
+
+// NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs from the specified `proc` filesystem.
+func (fs FS) NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
+	file, err := os.Open(fs.Path("net/ip_vs"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseIPVSBackendStatus(file)
+}
+
+func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
+	var (
+		status       []IPVSBackendStatus
+		scanner      = bufio.NewScanner(file)
+		proto        string
+		localAddress net.IP
+		localPort    uint16
+		err          error
+	)
+
+	for scanner.Scan() {
+		fields := strings.Fields(string(scanner.Text()))
+		if len(fields) == 0 {
+			continue
+		}
+		switch {
+		case fields[0] == "IP" || fields[0] == "Prot" || fields[1] == "RemoteAddress:Port":
+			continue
+		case fields[0] == "TCP" || fields[0] == "UDP":
+			if len(fields) < 2 {
+				continue
+			}
+			proto = fields[0]
+			localAddress, localPort, err = parseIPPort(fields[1])
+			if err != nil {
+				return nil, err
+			}
+		case fields[0] == "->":
+			if len(fields) < 6 {
+				continue
+			}
+			remoteAddress, remotePort, err := parseIPPort(fields[1])
+			if err != nil {
+				return nil, err
+			}
+			weight, err := strconv.ParseUint(fields[3], 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			activeConn, err := strconv.ParseUint(fields[4], 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			inactConn, err := strconv.ParseUint(fields[5], 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			status = append(status, IPVSBackendStatus{
+				LocalAddress:  localAddress,
+				LocalPort:     localPort,
+				RemoteAddress: remoteAddress,
+				RemotePort:    remotePort,
+				Proto:         proto,
+				Weight:        weight,
+				ActiveConn:    activeConn,
+				InactConn:     inactConn,
+			})
+		}
+	}
+	return status, nil
+}
+
+func parseIPPort(s string) (net.IP, uint16, error) {
+	tmp := strings.SplitN(s, ":", 2)
+
+	if len(tmp) != 2 {
+		return nil, 0, fmt.Errorf("invalid IP:Port: %s", s)
+	}
+
+	if len(tmp[0]) != 8 && len(tmp[0]) != 32 {
+		return nil, 0, fmt.Errorf("invalid IP: %s", tmp[0])
+	}
+
+	ip, err := hex.DecodeString(tmp[0])
+	if err != nil {
+		return nil, 0, err
+	}
+
+	port, err := strconv.ParseUint(tmp[1], 16, 16)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return ip, uint16(port), nil
+}
diff --git a/vendor/github.com/prometheus/procfs/mdstat.go b/vendor/github.com/prometheus/procfs/mdstat.go
new file mode 100644
index 00000000..d7a248c0
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/mdstat.go
@@ -0,0 +1,138 @@
+package procfs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	statuslineRE = regexp.MustCompile(`(\d+) blocks .*\[(\d+)/(\d+)\] \[[U_]+\]`)
+	buildlineRE  = regexp.MustCompile(`\((\d+)/\d+\)`)
+)
+
+// MDStat holds info parsed from /proc/mdstat.
+type MDStat struct {
+	// Name of the device.
+	Name string
+	// activity-state of the device.
+	ActivityState string
+	// Number of active disks.
+	DisksActive int64
+	// Total number of disks the device consists of.
+	DisksTotal int64
+	// Number of blocks the device holds.
+	BlocksTotal int64
+	// Number of blocks on the device that are in sync.
+	BlocksSynced int64
+}
+
+// ParseMDStat parses an mdstat-file and returns a struct with the relevant infos.
+func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
+	mdStatusFilePath := fs.Path("mdstat")
+	content, err := ioutil.ReadFile(mdStatusFilePath)
+	if err != nil {
+		return []MDStat{}, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+	}
+
+	mdStates := []MDStat{}
+	lines := strings.Split(string(content), "\n")
+	for i, l := range lines {
+		if l == "" {
+			continue
+		}
+		if l[0] == ' ' {
+			continue
+		}
+		if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
+			continue
+		}
+
+		mainLine := strings.Split(l, " ")
+		if len(mainLine) < 3 {
+			return mdStates, fmt.Errorf("error parsing mdline: %s", l)
+		}
+		mdName := mainLine[0]
+		activityState := mainLine[2]
+
+		if len(lines) <= i+3 {
+			return mdStates, fmt.Errorf(
+				"error parsing %s: too few lines for md device %s",
+				mdStatusFilePath,
+				mdName,
+			)
+		}
+
+		active, total, size, err := evalStatusline(lines[i+1])
+		if err != nil {
+			return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+		}
+
+		// j is the line number of the syncing-line.
+		j := i + 2
+		if strings.Contains(lines[i+2], "bitmap") { // skip bitmap line
+			j = i + 3
+		}
+
+		// If device is syncing at the moment, get the number of currently
+		// synced bytes, otherwise that number equals the size of the device.
+		syncedBlocks := size
+		if strings.Contains(lines[j], "recovery") || strings.Contains(lines[j], "resync") {
+			syncedBlocks, err = evalBuildline(lines[j])
+			if err != nil {
+				return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+			}
+		}
+
+		mdStates = append(mdStates, MDStat{
+			Name:          mdName,
+			ActivityState: activityState,
+			DisksActive:   active,
+			DisksTotal:    total,
+			BlocksTotal:   size,
+			BlocksSynced:  syncedBlocks,
+		})
+	}
+
+	return mdStates, nil
+}
+
+func evalStatusline(statusline string) (active, total, size int64, err error) {
+	matches := statuslineRE.FindStringSubmatch(statusline)
+	if len(matches) != 4 {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline: %s", statusline)
+	}
+
+	size, err = strconv.ParseInt(matches[1], 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	}
+
+	total, err = strconv.ParseInt(matches[2], 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	}
+
+	active, err = strconv.ParseInt(matches[3], 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	}
+
+	return active, total, size, nil
+}
+
+func evalBuildline(buildline string) (syncedBlocks int64, err error) {
+	matches := buildlineRE.FindStringSubmatch(buildline)
+	if len(matches) != 2 {
+		return 0, fmt.Errorf("unexpected buildline: %s", buildline)
+	}
+
+	syncedBlocks, err = strconv.ParseInt(matches[1], 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("%s in buildline: %s", err, buildline)
+	}
+
+	return syncedBlocks, nil
+}
diff --git a/vendor/github.com/prometheus/procfs/mountstats.go b/vendor/github.com/prometheus/procfs/mountstats.go
new file mode 100644
index 00000000..fe8f1f6a
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/mountstats.go
@@ -0,0 +1,552 @@
+package procfs
+
+// While implementing parsing of /proc/[pid]/mountstats, this blog was used
+// heavily as a reference:
+//   https://utcc.utoronto.ca/~cks/space/blog/linux/NFSMountstatsIndex
+//
+// Special thanks to Chris Siebenmann for all of his posts explaining the
+// various statistics available for NFS.
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Constants shared between multiple functions.
+const (
+	deviceEntryLen = 8
+
+	fieldBytesLen  = 8
+	fieldEventsLen = 27
+
+	statVersion10 = "1.0"
+	statVersion11 = "1.1"
+
+	fieldTransport10Len = 10
+	fieldTransport11Len = 13
+)
+
+// A Mount is a device mount parsed from /proc/[pid]/mountstats.
+type Mount struct {
+	// Name of the device.
+	Device string
+	// The mount point of the device.
+	Mount string
+	// The filesystem type used by the device.
+	Type string
+	// If available additional statistics related to this Mount.
+	// Use a type assertion to determine if additional statistics are available.
+	Stats MountStats
+}
+
+// A MountStats is a type which contains detailed statistics for a specific
+// type of Mount.
+type MountStats interface {
+	mountStats()
+}
+
+// A MountStatsNFS is a MountStats implementation for NFSv3 and v4 mounts.
+type MountStatsNFS struct {
+	// The version of statistics provided.
+	StatVersion string
+	// The age of the NFS mount.
+	Age time.Duration
+	// Statistics related to byte counters for various operations.
+	Bytes NFSBytesStats
+	// Statistics related to various NFS event occurrences.
+	Events NFSEventsStats
+	// Statistics broken down by filesystem operation.
+	Operations []NFSOperationStats
+	// Statistics about the NFS RPC transport.
+	Transport NFSTransportStats
+}
+
+// mountStats implements MountStats.
+func (m MountStatsNFS) mountStats() {}
+
+// A NFSBytesStats contains statistics about the number of bytes read and written
+// by an NFS client to and from an NFS server.
+type NFSBytesStats struct {
+	// Number of bytes read using the read() syscall.
+	Read uint64
+	// Number of bytes written using the write() syscall.
+	Write uint64
+	// Number of bytes read using the read() syscall in O_DIRECT mode.
+	DirectRead uint64
+	// Number of bytes written using the write() syscall in O_DIRECT mode.
+	DirectWrite uint64
+	// Number of bytes read from the NFS server, in total.
+	ReadTotal uint64
+	// Number of bytes written to the NFS server, in total.
+	WriteTotal uint64
+	// Number of pages read directly via mmap()'d files.
+	ReadPages uint64
+	// Number of pages written directly via mmap()'d files.
+	WritePages uint64
+}
+
+// A NFSEventsStats contains statistics about NFS event occurrences.
+type NFSEventsStats struct {
+	// Number of times cached inode attributes are re-validated from the server.
+	InodeRevalidate uint64
+	// Number of times cached dentry nodes are re-validated from the server.
+	DnodeRevalidate uint64
+	// Number of times an inode cache is cleared.
+	DataInvalidate uint64
+	// Number of times cached inode attributes are invalidated.
+	AttributeInvalidate uint64
+	// Number of times files or directories have been open()'d.
+	VFSOpen uint64
+	// Number of times a directory lookup has occurred.
+	VFSLookup uint64
+	// Number of times permissions have been checked.
+	VFSAccess uint64
+	// Number of updates (and potential writes) to pages.
+	VFSUpdatePage uint64
+	// Number of pages read directly via mmap()'d files.
+	VFSReadPage uint64
+	// Number of times a group of pages have been read.
+	VFSReadPages uint64
+	// Number of pages written directly via mmap()'d files.
+	VFSWritePage uint64
+	// Number of times a group of pages have been written.
+	VFSWritePages uint64
+	// Number of times directory entries have been read with getdents().
+	VFSGetdents uint64
+	// Number of times attributes have been set on inodes.
+	VFSSetattr uint64
+	// Number of pending writes that have been forcefully flushed to the server.
+	VFSFlush uint64
+	// Number of times fsync() has been called on directories and files.
+	VFSFsync uint64
+	// Number of times locking has been attempted on a file.
+	VFSLock uint64
+	// Number of times files have been closed and released.
+	VFSFileRelease uint64
+	// Unknown.  Possibly unused.
+	CongestionWait uint64
+	// Number of times files have been truncated.
+	Truncation uint64
+	// Number of times a file has been grown due to writes beyond its existing end.
+	WriteExtension uint64
+	// Number of times a file was removed while still open by another process.
+	SillyRename uint64
+	// Number of times the NFS server gave less data than expected while reading.
+	ShortRead uint64
+	// Number of times the NFS server wrote less data than expected while writing.
+	ShortWrite uint64
+	// Number of times the NFS server indicated EJUKEBOX; retrieving data from
+	// offline storage.
+	JukeboxDelay uint64
+	// Number of NFS v4.1+ pNFS reads.
+	PNFSRead uint64
+	// Number of NFS v4.1+ pNFS writes.
+	PNFSWrite uint64
+}
+
+// A NFSOperationStats contains statistics for a single operation.
+type NFSOperationStats struct {
+	// The name of the operation.
+	Operation string
+	// Number of requests performed for this operation.
+	Requests uint64
+	// Number of times an actual RPC request has been transmitted for this operation.
+	Transmissions uint64
+	// Number of times a request has had a major timeout.
+	MajorTimeouts uint64
+	// Number of bytes sent for this operation, including RPC headers and payload.
+	BytesSent uint64
+	// Number of bytes received for this operation, including RPC headers and payload.
+	BytesReceived uint64
+	// Duration all requests spent queued for transmission before they were sent.
+	CumulativeQueueTime time.Duration
+	// Duration it took to get a reply back after the request was transmitted.
+	CumulativeTotalResponseTime time.Duration
+	// Duration from when a request was enqueued to when it was completely handled.
+	CumulativeTotalRequestTime time.Duration
+}
+
+// A NFSTransportStats contains statistics for the NFS mount RPC requests and
+// responses.
+type NFSTransportStats struct {
+	// The local port used for the NFS mount.
+	Port uint64
+	// Number of times the client has had to establish a connection from scratch
+	// to the NFS server.
+	Bind uint64
+	// Number of times the client has made a TCP connection to the NFS server.
+	Connect uint64
+	// Duration (in jiffies, a kernel internal unit of time) the NFS mount has
+	// spent waiting for connections to the server to be established.
+	ConnectIdleTime uint64
+	// Duration since the NFS mount last saw any RPC traffic.
+	IdleTime time.Duration
+	// Number of RPC requests for this mount sent to the NFS server.
+	Sends uint64
+	// Number of RPC responses for this mount received from the NFS server.
+	Receives uint64
+	// Number of times the NFS server sent a response with a transaction ID
+	// unknown to this client.
+	BadTransactionIDs uint64
+	// A running counter, incremented on each request as the current difference
+	// ebetween sends and receives.
+	CumulativeActiveRequests uint64
+	// A running counter, incremented on each request by the current backlog
+	// queue size.
+	CumulativeBacklog uint64
+
+	// Stats below only available with stat version 1.1.
+
+	// Maximum number of simultaneously active RPC requests ever used.
+	MaximumRPCSlotsUsed uint64
+	// A running counter, incremented on each request as the current size of the
+	// sending queue.
+	CumulativeSendingQueue uint64
+	// A running counter, incremented on each request as the current size of the
+	// pending queue.
+	CumulativePendingQueue uint64
+}
+
+// parseMountStats parses a /proc/[pid]/mountstats file and returns a slice
+// of Mount structures containing detailed information about each mount.
+// If available, statistics for each mount are parsed as well.
+func parseMountStats(r io.Reader) ([]*Mount, error) {
+	const (
+		device            = "device"
+		statVersionPrefix = "statvers="
+
+		nfs3Type = "nfs"
+		nfs4Type = "nfs4"
+	)
+
+	var mounts []*Mount
+
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		// Only look for device entries in this function
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) == 0 || ss[0] != device {
+			continue
+		}
+
+		m, err := parseMount(ss)
+		if err != nil {
+			return nil, err
+		}
+
+		// Does this mount also possess statistics information?
+		if len(ss) > deviceEntryLen {
+			// Only NFSv3 and v4 are supported for parsing statistics
+			if m.Type != nfs3Type && m.Type != nfs4Type {
+				return nil, fmt.Errorf("cannot parse MountStats for fstype %q", m.Type)
+			}
+
+			statVersion := strings.TrimPrefix(ss[8], statVersionPrefix)
+
+			stats, err := parseMountStatsNFS(s, statVersion)
+			if err != nil {
+				return nil, err
+			}
+
+			m.Stats = stats
+		}
+
+		mounts = append(mounts, m)
+	}
+
+	return mounts, s.Err()
+}
+
+// parseMount parses an entry in /proc/[pid]/mountstats in the format:
+//   device [device] mounted on [mount] with fstype [type]
+func parseMount(ss []string) (*Mount, error) {
+	if len(ss) < deviceEntryLen {
+		return nil, fmt.Errorf("invalid device entry: %v", ss)
+	}
+
+	// Check for specific words appearing at specific indices to ensure
+	// the format is consistent with what we expect
+	format := []struct {
+		i int
+		s string
+	}{
+		{i: 0, s: "device"},
+		{i: 2, s: "mounted"},
+		{i: 3, s: "on"},
+		{i: 5, s: "with"},
+		{i: 6, s: "fstype"},
+	}
+
+	for _, f := range format {
+		if ss[f.i] != f.s {
+			return nil, fmt.Errorf("invalid device entry: %v", ss)
+		}
+	}
+
+	return &Mount{
+		Device: ss[1],
+		Mount:  ss[4],
+		Type:   ss[7],
+	}, nil
+}
+
+// parseMountStatsNFS parses a MountStatsNFS by scanning additional information
+// related to NFS statistics.
+func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, error) {
+	// Field indicators for parsing specific types of data
+	const (
+		fieldAge        = "age:"
+		fieldBytes      = "bytes:"
+		fieldEvents     = "events:"
+		fieldPerOpStats = "per-op"
+		fieldTransport  = "xprt:"
+	)
+
+	stats := &MountStatsNFS{
+		StatVersion: statVersion,
+	}
+
+	for s.Scan() {
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) == 0 {
+			break
+		}
+		if len(ss) < 2 {
+			return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
+		}
+
+		switch ss[0] {
+		case fieldAge:
+			// Age integer is in seconds
+			d, err := time.ParseDuration(ss[1] + "s")
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Age = d
+		case fieldBytes:
+			bstats, err := parseNFSBytesStats(ss[1:])
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Bytes = *bstats
+		case fieldEvents:
+			estats, err := parseNFSEventsStats(ss[1:])
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Events = *estats
+		case fieldTransport:
+			if len(ss) < 3 {
+				return nil, fmt.Errorf("not enough information for NFS transport stats: %v", ss)
+			}
+
+			tstats, err := parseNFSTransportStats(ss[2:], statVersion)
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Transport = *tstats
+		}
+
+		// When encountering "per-operation statistics", we must break this
+		// loop and parse them separately to ensure we can terminate parsing
+		// before reaching another device entry; hence why this 'if' statement
+		// is not just another switch case
+		if ss[0] == fieldPerOpStats {
+			break
+		}
+	}
+
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	// NFS per-operation stats appear last before the next device entry
+	perOpStats, err := parseNFSOperationStats(s)
+	if err != nil {
+		return nil, err
+	}
+
+	stats.Operations = perOpStats
+
+	return stats, nil
+}
+
+// parseNFSBytesStats parses a NFSBytesStats line using an input set of
+// integer fields.
+func parseNFSBytesStats(ss []string) (*NFSBytesStats, error) {
+	if len(ss) != fieldBytesLen {
+		return nil, fmt.Errorf("invalid NFS bytes stats: %v", ss)
+	}
+
+	ns := make([]uint64, 0, fieldBytesLen)
+	for _, s := range ss {
+		n, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		ns = append(ns, n)
+	}
+
+	return &NFSBytesStats{
+		Read:        ns[0],
+		Write:       ns[1],
+		DirectRead:  ns[2],
+		DirectWrite: ns[3],
+		ReadTotal:   ns[4],
+		WriteTotal:  ns[5],
+		ReadPages:   ns[6],
+		WritePages:  ns[7],
+	}, nil
+}
+
+// parseNFSEventsStats parses a NFSEventsStats line using an input set of
+// integer fields.
+func parseNFSEventsStats(ss []string) (*NFSEventsStats, error) {
+	if len(ss) != fieldEventsLen {
+		return nil, fmt.Errorf("invalid NFS events stats: %v", ss)
+	}
+
+	ns := make([]uint64, 0, fieldEventsLen)
+	for _, s := range ss {
+		n, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		ns = append(ns, n)
+	}
+
+	return &NFSEventsStats{
+		InodeRevalidate:     ns[0],
+		DnodeRevalidate:     ns[1],
+		DataInvalidate:      ns[2],
+		AttributeInvalidate: ns[3],
+		VFSOpen:             ns[4],
+		VFSLookup:           ns[5],
+		VFSAccess:           ns[6],
+		VFSUpdatePage:       ns[7],
+		VFSReadPage:         ns[8],
+		VFSReadPages:        ns[9],
+		VFSWritePage:        ns[10],
+		VFSWritePages:       ns[11],
+		VFSGetdents:         ns[12],
+		VFSSetattr:          ns[13],
+		VFSFlush:            ns[14],
+		VFSFsync:            ns[15],
+		VFSLock:             ns[16],
+		VFSFileRelease:      ns[17],
+		CongestionWait:      ns[18],
+		Truncation:          ns[19],
+		WriteExtension:      ns[20],
+		SillyRename:         ns[21],
+		ShortRead:           ns[22],
+		ShortWrite:          ns[23],
+		JukeboxDelay:        ns[24],
+		PNFSRead:            ns[25],
+		PNFSWrite:           ns[26],
+	}, nil
+}
+
+// parseNFSOperationStats parses a slice of NFSOperationStats by scanning
+// additional information about per-operation statistics until an empty
+// line is reached.
+func parseNFSOperationStats(s *bufio.Scanner) ([]NFSOperationStats, error) {
+	const (
+		// Number of expected fields in each per-operation statistics set
+		numFields = 9
+	)
+
+	var ops []NFSOperationStats
+
+	for s.Scan() {
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) == 0 {
+			// Must break when reading a blank line after per-operation stats to
+			// enable top-level function to parse the next device entry
+			break
+		}
+
+		if len(ss) != numFields {
+			return nil, fmt.Errorf("invalid NFS per-operations stats: %v", ss)
+		}
+
+		// Skip string operation name for integers
+		ns := make([]uint64, 0, numFields-1)
+		for _, st := range ss[1:] {
+			n, err := strconv.ParseUint(st, 10, 64)
+			if err != nil {
+				return nil, err
+			}
+
+			ns = append(ns, n)
+		}
+
+		ops = append(ops, NFSOperationStats{
+			Operation:                   strings.TrimSuffix(ss[0], ":"),
+			Requests:                    ns[0],
+			Transmissions:               ns[1],
+			MajorTimeouts:               ns[2],
+			BytesSent:                   ns[3],
+			BytesReceived:               ns[4],
+			CumulativeQueueTime:         time.Duration(ns[5]) * time.Millisecond,
+			CumulativeTotalResponseTime: time.Duration(ns[6]) * time.Millisecond,
+			CumulativeTotalRequestTime:  time.Duration(ns[7]) * time.Millisecond,
+		})
+	}
+
+	return ops, s.Err()
+}
+
+// parseNFSTransportStats parses a NFSTransportStats line using an input set of
+// integer fields matched to a specific stats version.
+func parseNFSTransportStats(ss []string, statVersion string) (*NFSTransportStats, error) {
+	switch statVersion {
+	case statVersion10:
+		if len(ss) != fieldTransport10Len {
+			return nil, fmt.Errorf("invalid NFS transport stats 1.0 statement: %v", ss)
+		}
+	case statVersion11:
+		if len(ss) != fieldTransport11Len {
+			return nil, fmt.Errorf("invalid NFS transport stats 1.1 statement: %v", ss)
+		}
+	default:
+		return nil, fmt.Errorf("unrecognized NFS transport stats version: %q", statVersion)
+	}
+
+	// Allocate enough for v1.1 stats since zero value for v1.1 stats will be okay
+	// in a v1.0 response
+	ns := make([]uint64, 0, fieldTransport11Len)
+	for _, s := range ss {
+		n, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		ns = append(ns, n)
+	}
+
+	return &NFSTransportStats{
+		Port:                     ns[0],
+		Bind:                     ns[1],
+		Connect:                  ns[2],
+		ConnectIdleTime:          ns[3],
+		IdleTime:                 time.Duration(ns[4]) * time.Second,
+		Sends:                    ns[5],
+		Receives:                 ns[6],
+		BadTransactionIDs:        ns[7],
+		CumulativeActiveRequests: ns[8],
+		CumulativeBacklog:        ns[9],
+		MaximumRPCSlotsUsed:      ns[10],
+		CumulativeSendingQueue:   ns[11],
+		CumulativePendingQueue:   ns[12],
+	}, nil
+}
diff --git a/vendor/github.com/prometheus/procfs/proc.go b/vendor/github.com/prometheus/procfs/proc.go
index 21445cf1..8717e1fe 100644
--- a/vendor/github.com/prometheus/procfs/proc.go
+++ b/vendor/github.com/prometheus/procfs/proc.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"path"
 	"strconv"
 	"strings"
 )
@@ -24,9 +23,13 @@ func (p Procs) Len() int           { return len(p) }
 func (p Procs) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
 func (p Procs) Less(i, j int) bool { return p[i].PID < p[j].PID }
 
-// Self returns a process for the current process.
+// Self returns a process for the current process read via /proc/self.
 func Self() (Proc, error) {
-	return NewProc(os.Getpid())
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return Proc{}, err
+	}
+	return fs.Self()
 }
 
 // NewProc returns a process for the given pid under /proc.
@@ -35,32 +38,42 @@ func NewProc(pid int) (Proc, error) {
 	if err != nil {
 		return Proc{}, err
 	}
-
 	return fs.NewProc(pid)
 }
 
-// AllProcs returns a list of all currently avaible processes under /proc.
+// AllProcs returns a list of all currently available processes under /proc.
 func AllProcs() (Procs, error) {
 	fs, err := NewFS(DefaultMountPoint)
 	if err != nil {
 		return Procs{}, err
 	}
-
 	return fs.AllProcs()
 }
 
+// Self returns a process for the current process.
+func (fs FS) Self() (Proc, error) {
+	p, err := os.Readlink(fs.Path("self"))
+	if err != nil {
+		return Proc{}, err
+	}
+	pid, err := strconv.Atoi(strings.Replace(p, string(fs), "", -1))
+	if err != nil {
+		return Proc{}, err
+	}
+	return fs.NewProc(pid)
+}
+
 // NewProc returns a process for the given pid.
 func (fs FS) NewProc(pid int) (Proc, error) {
-	if _, err := fs.stat(strconv.Itoa(pid)); err != nil {
+	if _, err := os.Stat(fs.Path(strconv.Itoa(pid))); err != nil {
 		return Proc{}, err
 	}
-
 	return Proc{PID: pid, fs: fs}, nil
 }
 
-// AllProcs returns a list of all currently avaible processes.
+// AllProcs returns a list of all currently available processes.
 func (fs FS) AllProcs() (Procs, error) {
-	d, err := fs.open("")
+	d, err := os.Open(fs.Path())
 	if err != nil {
 		return Procs{}, err
 	}
@@ -85,7 +98,7 @@ func (fs FS) AllProcs() (Procs, error) {
 
 // CmdLine returns the command line of a process.
 func (p Proc) CmdLine() ([]string, error) {
-	f, err := p.open("cmdline")
+	f, err := os.Open(p.path("cmdline"))
 	if err != nil {
 		return nil, err
 	}
@@ -96,9 +109,39 @@ func (p Proc) CmdLine() ([]string, error) {
 		return nil, err
 	}
 
+	if len(data) < 1 {
+		return []string{}, nil
+	}
+
 	return strings.Split(string(data[:len(data)-1]), string(byte(0))), nil
 }
 
+// Comm returns the command name of a process.
+func (p Proc) Comm() (string, error) {
+	f, err := os.Open(p.path("comm"))
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSpace(string(data)), nil
+}
+
+// Executable returns the absolute path of the executable command of a process.
+func (p Proc) Executable() (string, error) {
+	exe, err := os.Readlink(p.path("exe"))
+	if os.IsNotExist(err) {
+		return "", nil
+	}
+
+	return exe, err
+}
+
 // FileDescriptors returns the currently open file descriptors of a process.
 func (p Proc) FileDescriptors() ([]uintptr, error) {
 	names, err := p.fileDescriptors()
@@ -118,6 +161,26 @@ func (p Proc) FileDescriptors() ([]uintptr, error) {
 	return fds, nil
 }
 
+// FileDescriptorTargets returns the targets of all file descriptors of a process.
+// If a file descriptor is not a symlink to a file (like a socket), that value will be the empty string.
+func (p Proc) FileDescriptorTargets() ([]string, error) {
+	names, err := p.fileDescriptors()
+	if err != nil {
+		return nil, err
+	}
+
+	targets := make([]string, len(names))
+
+	for i, name := range names {
+		target, err := os.Readlink(p.path("fd", name))
+		if err == nil {
+			targets[i] = target
+		}
+	}
+
+	return targets, nil
+}
+
 // FileDescriptorsLen returns the number of currently open file descriptors of
 // a process.
 func (p Proc) FileDescriptorsLen() (int, error) {
@@ -129,8 +192,20 @@ func (p Proc) FileDescriptorsLen() (int, error) {
 	return len(fds), nil
 }
 
+// MountStats retrieves statistics and configuration for mount points in a
+// process's namespace.
+func (p Proc) MountStats() ([]*Mount, error) {
+	f, err := os.Open(p.path("mountstats"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return parseMountStats(f)
+}
+
 func (p Proc) fileDescriptors() ([]string, error) {
-	d, err := p.open("fd")
+	d, err := os.Open(p.path("fd"))
 	if err != nil {
 		return nil, err
 	}
@@ -144,6 +219,6 @@ func (p Proc) fileDescriptors() ([]string, error) {
 	return names, nil
 }
 
-func (p Proc) open(pa string) (*os.File, error) {
-	return p.fs.open(path.Join(strconv.Itoa(p.PID), pa))
+func (p Proc) path(pa ...string) string {
+	return p.fs.Path(append([]string{strconv.Itoa(p.PID)}, pa...)...)
 }
diff --git a/vendor/github.com/prometheus/procfs/proc_io.go b/vendor/github.com/prometheus/procfs/proc_io.go
new file mode 100644
index 00000000..b4e31d7b
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc_io.go
@@ -0,0 +1,55 @@
+package procfs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+// ProcIO models the content of /proc/<pid>/io.
+type ProcIO struct {
+	// Chars read.
+	RChar uint64
+	// Chars written.
+	WChar uint64
+	// Read syscalls.
+	SyscR uint64
+	// Write syscalls.
+	SyscW uint64
+	// Bytes read.
+	ReadBytes uint64
+	// Bytes written.
+	WriteBytes uint64
+	// Bytes written, but taking into account truncation. See
+	// Documentation/filesystems/proc.txt in the kernel sources for
+	// detailed explanation.
+	CancelledWriteBytes int64
+}
+
+// NewIO creates a new ProcIO instance from a given Proc instance.
+func (p Proc) NewIO() (ProcIO, error) {
+	pio := ProcIO{}
+
+	f, err := os.Open(p.path("io"))
+	if err != nil {
+		return pio, err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return pio, err
+	}
+
+	ioFormat := "rchar: %d\nwchar: %d\nsyscr: %d\nsyscw: %d\n" +
+		"read_bytes: %d\nwrite_bytes: %d\n" +
+		"cancelled_write_bytes: %d\n"
+
+	_, err = fmt.Sscanf(string(data), ioFormat, &pio.RChar, &pio.WChar, &pio.SyscR,
+		&pio.SyscW, &pio.ReadBytes, &pio.WriteBytes, &pio.CancelledWriteBytes)
+	if err != nil {
+		return pio, err
+	}
+
+	return pio, nil
+}
diff --git a/vendor/github.com/prometheus/procfs/proc_limits.go b/vendor/github.com/prometheus/procfs/proc_limits.go
index 9f080b9f..2df997ce 100644
--- a/vendor/github.com/prometheus/procfs/proc_limits.go
+++ b/vendor/github.com/prometheus/procfs/proc_limits.go
@@ -3,29 +3,56 @@ package procfs
 import (
 	"bufio"
 	"fmt"
+	"os"
 	"regexp"
 	"strconv"
 )
 
 // ProcLimits represents the soft limits for each of the process's resource
-// limits.
+// limits. For more information see getrlimit(2):
+// http://man7.org/linux/man-pages/man2/getrlimit.2.html.
 type ProcLimits struct {
-	CPUTime          int
-	FileSize         int
-	DataSize         int
-	StackSize        int
-	CoreFileSize     int
-	ResidentSet      int
-	Processes        int
-	OpenFiles        int
-	LockedMemory     int
-	AddressSpace     int
-	FileLocks        int
-	PendingSignals   int
-	MsqqueueSize     int
-	NicePriority     int
+	// CPU time limit in seconds.
+	CPUTime int
+	// Maximum size of files that the process may create.
+	FileSize int
+	// Maximum size of the process's data segment (initialized data,
+	// uninitialized data, and heap).
+	DataSize int
+	// Maximum size of the process stack in bytes.
+	StackSize int
+	// Maximum size of a core file.
+	CoreFileSize int
+	// Limit of the process's resident set in pages.
+	ResidentSet int
+	// Maximum number of processes that can be created for the real user ID of
+	// the calling process.
+	Processes int
+	// Value one greater than the maximum file descriptor number that can be
+	// opened by this process.
+	OpenFiles int
+	// Maximum number of bytes of memory that may be locked into RAM.
+	LockedMemory int
+	// Maximum size of the process's virtual memory address space in bytes.
+	AddressSpace int
+	// Limit on the combined number of flock(2) locks and fcntl(2) leases that
+	// this process may establish.
+	FileLocks int
+	// Limit of signals that may be queued for the real user ID of the calling
+	// process.
+	PendingSignals int
+	// Limit on the number of bytes that can be allocated for POSIX message
+	// queues for the real user ID of the calling process.
+	MsqqueueSize int
+	// Limit of the nice priority set using setpriority(2) or nice(2).
+	NicePriority int
+	// Limit of the real-time priority set using sched_setscheduler(2) or
+	// sched_setparam(2).
 	RealtimePriority int
-	RealtimeTimeout  int
+	// Limit (in microseconds) on the amount of CPU time that a process
+	// scheduled under a real-time scheduling policy may consume without making
+	// a blocking system call.
+	RealtimeTimeout int
 }
 
 const (
@@ -39,7 +66,7 @@ var (
 
 // NewLimits returns the current soft limits of the process.
 func (p Proc) NewLimits() (ProcLimits, error) {
-	f, err := p.open("limits")
+	f, err := os.Open(p.path("limits"))
 	if err != nil {
 		return ProcLimits{}, err
 	}
@@ -60,7 +87,7 @@ func (p Proc) NewLimits() (ProcLimits, error) {
 		case "Max cpu time":
 			l.CPUTime, err = parseInt(fields[1])
 		case "Max file size":
-			l.FileLocks, err = parseInt(fields[1])
+			l.FileSize, err = parseInt(fields[1])
 		case "Max data size":
 			l.DataSize, err = parseInt(fields[1])
 		case "Max stack size":
@@ -90,7 +117,6 @@ func (p Proc) NewLimits() (ProcLimits, error) {
 		case "Max realtime timeout":
 			l.RealtimeTimeout, err = parseInt(fields[1])
 		}
-
 		if err != nil {
 			return ProcLimits{}, err
 		}
diff --git a/vendor/github.com/prometheus/procfs/proc_stat.go b/vendor/github.com/prometheus/procfs/proc_stat.go
index 1e027762..724e271b 100644
--- a/vendor/github.com/prometheus/procfs/proc_stat.go
+++ b/vendor/github.com/prometheus/procfs/proc_stat.go
@@ -7,8 +7,22 @@ import (
 	"os"
 )
 
-// #include <unistd.h>
-import "C"
+// Originally, this USER_HZ value was dynamically retrieved via a sysconf call
+// which required cgo. However, that caused a lot of problems regarding
+// cross-compilation. Alternatives such as running a binary to determine the
+// value, or trying to derive it in some other way were all problematic.  After
+// much research it was determined that USER_HZ is actually hardcoded to 100 on
+// all Go-supported platforms as of the time of this writing. This is why we
+// decided to hardcode it here as well. It is not impossible that there could
+// be systems with exceptions, but they should be very exotic edge cases, and
+// in that case, the worst outcome will be two misreported metrics.
+//
+// See also the following discussions:
+//
+// - https://github.com/prometheus/node_exporter/issues/52
+// - https://github.com/prometheus/procfs/pull/2
+// - http://stackoverflow.com/questions/17410841/how-does-user-hz-solve-the-jiffy-scaling-issue
+const userHZ = 100
 
 // ProcStat provides status information about the process,
 // read from /proc/[pid]/stat.
@@ -77,7 +91,7 @@ type ProcStat struct {
 
 // NewStat returns the current status information of the process.
 func (p Proc) NewStat() (ProcStat, error) {
-	f, err := p.open("stat")
+	f, err := os.Open(p.path("stat"))
 	if err != nil {
 		return ProcStat{}, err
 	}
@@ -152,14 +166,10 @@ func (s ProcStat) StartTime() (float64, error) {
 	if err != nil {
 		return 0, err
 	}
-	return float64(stat.BootTime) + (float64(s.Starttime) / ticks()), nil
+	return float64(stat.BootTime) + (float64(s.Starttime) / userHZ), nil
 }
 
 // CPUTime returns the total CPU user and system time in seconds.
 func (s ProcStat) CPUTime() float64 {
-	return float64(s.UTime+s.STime) / ticks()
-}
-
-func ticks() float64 {
-	return float64(C.sysconf(C._SC_CLK_TCK)) // most likely 100
+	return float64(s.UTime+s.STime) / userHZ
 }
diff --git a/vendor/github.com/prometheus/procfs/stat.go b/vendor/github.com/prometheus/procfs/stat.go
index 26fefb0f..1ca217e8 100644
--- a/vendor/github.com/prometheus/procfs/stat.go
+++ b/vendor/github.com/prometheus/procfs/stat.go
@@ -3,6 +3,7 @@ package procfs
 import (
 	"bufio"
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 )
@@ -25,7 +26,7 @@ func NewStat() (Stat, error) {
 
 // NewStat returns an information about current kernel/system statistics.
 func (fs FS) NewStat() (Stat, error) {
-	f, err := fs.open("stat")
+	f, err := os.Open(fs.Path("stat"))
 	if err != nil {
 		return Stat{}, err
 	}
diff --git a/vendor/github.com/prometheus/procfs/xfs/parse.go b/vendor/github.com/prometheus/procfs/xfs/parse.go
new file mode 100644
index 00000000..d1285fa6
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/xfs/parse.go
@@ -0,0 +1,361 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package xfs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"strconv"
+	"strings"
+)
+
+// ParseStats parses a Stats from an input io.Reader, using the format
+// found in /proc/fs/xfs/stat.
+func ParseStats(r io.Reader) (*Stats, error) {
+	const (
+		// Fields parsed into stats structures.
+		fieldExtentAlloc = "extent_alloc"
+		fieldAbt         = "abt"
+		fieldBlkMap      = "blk_map"
+		fieldBmbt        = "bmbt"
+		fieldDir         = "dir"
+		fieldTrans       = "trans"
+		fieldIg          = "ig"
+		fieldLog         = "log"
+		fieldRw          = "rw"
+		fieldAttr        = "attr"
+		fieldIcluster    = "icluster"
+		fieldVnodes      = "vnodes"
+		fieldBuf         = "buf"
+		fieldXpc         = "xpc"
+
+		// Unimplemented at this time due to lack of documentation.
+		fieldPushAil = "push_ail"
+		fieldXstrat  = "xstrat"
+		fieldAbtb2   = "abtb2"
+		fieldAbtc2   = "abtc2"
+		fieldBmbt2   = "bmbt2"
+		fieldIbt2    = "ibt2"
+		fieldFibt2   = "fibt2"
+		fieldQm      = "qm"
+		fieldDebug   = "debug"
+	)
+
+	var xfss Stats
+
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		// Expect at least a string label and a single integer value, ex:
+		//   - abt 0
+		//   - rw 1 2
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) < 2 {
+			continue
+		}
+		label := ss[0]
+
+		// Extended precision counters are uint64 values.
+		if label == fieldXpc {
+			us, err := parseUint64s(ss[1:])
+			if err != nil {
+				return nil, err
+			}
+
+			xfss.ExtendedPrecision, err = extendedPrecisionStats(us)
+			if err != nil {
+				return nil, err
+			}
+
+			continue
+		}
+
+		// All other counters are uint32 values.
+		us, err := parseUint32s(ss[1:])
+		if err != nil {
+			return nil, err
+		}
+
+		switch label {
+		case fieldExtentAlloc:
+			xfss.ExtentAllocation, err = extentAllocationStats(us)
+		case fieldAbt:
+			xfss.AllocationBTree, err = btreeStats(us)
+		case fieldBlkMap:
+			xfss.BlockMapping, err = blockMappingStats(us)
+		case fieldBmbt:
+			xfss.BlockMapBTree, err = btreeStats(us)
+		case fieldDir:
+			xfss.DirectoryOperation, err = directoryOperationStats(us)
+		case fieldTrans:
+			xfss.Transaction, err = transactionStats(us)
+		case fieldIg:
+			xfss.InodeOperation, err = inodeOperationStats(us)
+		case fieldLog:
+			xfss.LogOperation, err = logOperationStats(us)
+		case fieldRw:
+			xfss.ReadWrite, err = readWriteStats(us)
+		case fieldAttr:
+			xfss.AttributeOperation, err = attributeOperationStats(us)
+		case fieldIcluster:
+			xfss.InodeClustering, err = inodeClusteringStats(us)
+		case fieldVnodes:
+			xfss.Vnode, err = vnodeStats(us)
+		case fieldBuf:
+			xfss.Buffer, err = bufferStats(us)
+		}
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &xfss, s.Err()
+}
+
+// extentAllocationStats builds an ExtentAllocationStats from a slice of uint32s.
+func extentAllocationStats(us []uint32) (ExtentAllocationStats, error) {
+	if l := len(us); l != 4 {
+		return ExtentAllocationStats{}, fmt.Errorf("incorrect number of values for XFS extent allocation stats: %d", l)
+	}
+
+	return ExtentAllocationStats{
+		ExtentsAllocated: us[0],
+		BlocksAllocated:  us[1],
+		ExtentsFreed:     us[2],
+		BlocksFreed:      us[3],
+	}, nil
+}
+
+// btreeStats builds a BTreeStats from a slice of uint32s.
+func btreeStats(us []uint32) (BTreeStats, error) {
+	if l := len(us); l != 4 {
+		return BTreeStats{}, fmt.Errorf("incorrect number of values for XFS btree stats: %d", l)
+	}
+
+	return BTreeStats{
+		Lookups:         us[0],
+		Compares:        us[1],
+		RecordsInserted: us[2],
+		RecordsDeleted:  us[3],
+	}, nil
+}
+
+// BlockMappingStat builds a BlockMappingStats from a slice of uint32s.
+func blockMappingStats(us []uint32) (BlockMappingStats, error) {
+	if l := len(us); l != 7 {
+		return BlockMappingStats{}, fmt.Errorf("incorrect number of values for XFS block mapping stats: %d", l)
+	}
+
+	return BlockMappingStats{
+		Reads:                us[0],
+		Writes:               us[1],
+		Unmaps:               us[2],
+		ExtentListInsertions: us[3],
+		ExtentListDeletions:  us[4],
+		ExtentListLookups:    us[5],
+		ExtentListCompares:   us[6],
+	}, nil
+}
+
+// DirectoryOperationStats builds a DirectoryOperationStats from a slice of uint32s.
+func directoryOperationStats(us []uint32) (DirectoryOperationStats, error) {
+	if l := len(us); l != 4 {
+		return DirectoryOperationStats{}, fmt.Errorf("incorrect number of values for XFS directory operation stats: %d", l)
+	}
+
+	return DirectoryOperationStats{
+		Lookups:  us[0],
+		Creates:  us[1],
+		Removes:  us[2],
+		Getdents: us[3],
+	}, nil
+}
+
+// TransactionStats builds a TransactionStats from a slice of uint32s.
+func transactionStats(us []uint32) (TransactionStats, error) {
+	if l := len(us); l != 3 {
+		return TransactionStats{}, fmt.Errorf("incorrect number of values for XFS transaction stats: %d", l)
+	}
+
+	return TransactionStats{
+		Sync:  us[0],
+		Async: us[1],
+		Empty: us[2],
+	}, nil
+}
+
+// InodeOperationStats builds an InodeOperationStats from a slice of uint32s.
+func inodeOperationStats(us []uint32) (InodeOperationStats, error) {
+	if l := len(us); l != 7 {
+		return InodeOperationStats{}, fmt.Errorf("incorrect number of values for XFS inode operation stats: %d", l)
+	}
+
+	return InodeOperationStats{
+		Attempts:        us[0],
+		Found:           us[1],
+		Recycle:         us[2],
+		Missed:          us[3],
+		Duplicate:       us[4],
+		Reclaims:        us[5],
+		AttributeChange: us[6],
+	}, nil
+}
+
+// LogOperationStats builds a LogOperationStats from a slice of uint32s.
+func logOperationStats(us []uint32) (LogOperationStats, error) {
+	if l := len(us); l != 5 {
+		return LogOperationStats{}, fmt.Errorf("incorrect number of values for XFS log operation stats: %d", l)
+	}
+
+	return LogOperationStats{
+		Writes:            us[0],
+		Blocks:            us[1],
+		NoInternalBuffers: us[2],
+		Force:             us[3],
+		ForceSleep:        us[4],
+	}, nil
+}
+
+// ReadWriteStats builds a ReadWriteStats from a slice of uint32s.
+func readWriteStats(us []uint32) (ReadWriteStats, error) {
+	if l := len(us); l != 2 {
+		return ReadWriteStats{}, fmt.Errorf("incorrect number of values for XFS read write stats: %d", l)
+	}
+
+	return ReadWriteStats{
+		Read:  us[0],
+		Write: us[1],
+	}, nil
+}
+
+// AttributeOperationStats builds an AttributeOperationStats from a slice of uint32s.
+func attributeOperationStats(us []uint32) (AttributeOperationStats, error) {
+	if l := len(us); l != 4 {
+		return AttributeOperationStats{}, fmt.Errorf("incorrect number of values for XFS attribute operation stats: %d", l)
+	}
+
+	return AttributeOperationStats{
+		Get:    us[0],
+		Set:    us[1],
+		Remove: us[2],
+		List:   us[3],
+	}, nil
+}
+
+// InodeClusteringStats builds an InodeClusteringStats from a slice of uint32s.
+func inodeClusteringStats(us []uint32) (InodeClusteringStats, error) {
+	if l := len(us); l != 3 {
+		return InodeClusteringStats{}, fmt.Errorf("incorrect number of values for XFS inode clustering stats: %d", l)
+	}
+
+	return InodeClusteringStats{
+		Iflush:     us[0],
+		Flush:      us[1],
+		FlushInode: us[2],
+	}, nil
+}
+
+// VnodeStats builds a VnodeStats from a slice of uint32s.
+func vnodeStats(us []uint32) (VnodeStats, error) {
+	// The attribute "Free" appears to not be available on older XFS
+	// stats versions.  Therefore, 7 or 8 elements may appear in
+	// this slice.
+	l := len(us)
+	log.Println(l)
+	if l != 7 && l != 8 {
+		return VnodeStats{}, fmt.Errorf("incorrect number of values for XFS vnode stats: %d", l)
+	}
+
+	s := VnodeStats{
+		Active:   us[0],
+		Allocate: us[1],
+		Get:      us[2],
+		Hold:     us[3],
+		Release:  us[4],
+		Reclaim:  us[5],
+		Remove:   us[6],
+	}
+
+	// Skip adding free, unless it is present. The zero value will
+	// be used in place of an actual count.
+	if l == 7 {
+		return s, nil
+	}
+
+	s.Free = us[7]
+	return s, nil
+}
+
+// BufferStats builds a BufferStats from a slice of uint32s.
+func bufferStats(us []uint32) (BufferStats, error) {
+	if l := len(us); l != 9 {
+		return BufferStats{}, fmt.Errorf("incorrect number of values for XFS buffer stats: %d", l)
+	}
+
+	return BufferStats{
+		Get:             us[0],
+		Create:          us[1],
+		GetLocked:       us[2],
+		GetLockedWaited: us[3],
+		BusyLocked:      us[4],
+		MissLocked:      us[5],
+		PageRetries:     us[6],
+		PageFound:       us[7],
+		GetRead:         us[8],
+	}, nil
+}
+
+// ExtendedPrecisionStats builds an ExtendedPrecisionStats from a slice of uint32s.
+func extendedPrecisionStats(us []uint64) (ExtendedPrecisionStats, error) {
+	if l := len(us); l != 3 {
+		return ExtendedPrecisionStats{}, fmt.Errorf("incorrect number of values for XFS extended precision stats: %d", l)
+	}
+
+	return ExtendedPrecisionStats{
+		FlushBytes: us[0],
+		WriteBytes: us[1],
+		ReadBytes:  us[2],
+	}, nil
+}
+
+// parseUint32s parses a slice of strings into a slice of uint32s.
+func parseUint32s(ss []string) ([]uint32, error) {
+	us := make([]uint32, 0, len(ss))
+	for _, s := range ss {
+		u, err := strconv.ParseUint(s, 10, 32)
+		if err != nil {
+			return nil, err
+		}
+
+		us = append(us, uint32(u))
+	}
+
+	return us, nil
+}
+
+// parseUint64s parses a slice of strings into a slice of uint64s.
+func parseUint64s(ss []string) ([]uint64, error) {
+	us := make([]uint64, 0, len(ss))
+	for _, s := range ss {
+		u, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		us = append(us, u)
+	}
+
+	return us, nil
+}
diff --git a/vendor/github.com/prometheus/procfs/xfs/xfs.go b/vendor/github.com/prometheus/procfs/xfs/xfs.go
new file mode 100644
index 00000000..ed77d907
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/xfs/xfs.go
@@ -0,0 +1,158 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package xfs provides access to statistics exposed by the XFS filesystem.
+package xfs
+
+// Stats contains XFS filesystem runtime statistics, parsed from
+// /proc/fs/xfs/stat.
+//
+// The names and meanings of each statistic were taken from
+// http://xfs.org/index.php/Runtime_Stats and xfs_stats.h in the Linux
+// kernel source. Most counters are uint32s (same data types used in
+// xfs_stats.h), but some of the "extended precision stats" are uint64s.
+type Stats struct {
+	ExtentAllocation   ExtentAllocationStats
+	AllocationBTree    BTreeStats
+	BlockMapping       BlockMappingStats
+	BlockMapBTree      BTreeStats
+	DirectoryOperation DirectoryOperationStats
+	Transaction        TransactionStats
+	InodeOperation     InodeOperationStats
+	LogOperation       LogOperationStats
+	ReadWrite          ReadWriteStats
+	AttributeOperation AttributeOperationStats
+	InodeClustering    InodeClusteringStats
+	Vnode              VnodeStats
+	Buffer             BufferStats
+	ExtendedPrecision  ExtendedPrecisionStats
+}
+
+// ExtentAllocationStats contains statistics regarding XFS extent allocations.
+type ExtentAllocationStats struct {
+	ExtentsAllocated uint32
+	BlocksAllocated  uint32
+	ExtentsFreed     uint32
+	BlocksFreed      uint32
+}
+
+// BTreeStats contains statistics regarding an XFS internal B-tree.
+type BTreeStats struct {
+	Lookups         uint32
+	Compares        uint32
+	RecordsInserted uint32
+	RecordsDeleted  uint32
+}
+
+// BlockMappingStats contains statistics regarding XFS block maps.
+type BlockMappingStats struct {
+	Reads                uint32
+	Writes               uint32
+	Unmaps               uint32
+	ExtentListInsertions uint32
+	ExtentListDeletions  uint32
+	ExtentListLookups    uint32
+	ExtentListCompares   uint32
+}
+
+// DirectoryOperationStats contains statistics regarding XFS directory entries.
+type DirectoryOperationStats struct {
+	Lookups  uint32
+	Creates  uint32
+	Removes  uint32
+	Getdents uint32
+}
+
+// TransactionStats contains statistics regarding XFS metadata transactions.
+type TransactionStats struct {
+	Sync  uint32
+	Async uint32
+	Empty uint32
+}
+
+// InodeOperationStats contains statistics regarding XFS inode operations.
+type InodeOperationStats struct {
+	Attempts        uint32
+	Found           uint32
+	Recycle         uint32
+	Missed          uint32
+	Duplicate       uint32
+	Reclaims        uint32
+	AttributeChange uint32
+}
+
+// LogOperationStats contains statistics regarding the XFS log buffer.
+type LogOperationStats struct {
+	Writes            uint32
+	Blocks            uint32
+	NoInternalBuffers uint32
+	Force             uint32
+	ForceSleep        uint32
+}
+
+// ReadWriteStats contains statistics regarding the number of read and write
+// system calls for XFS filesystems.
+type ReadWriteStats struct {
+	Read  uint32
+	Write uint32
+}
+
+// AttributeOperationStats contains statistics regarding manipulation of
+// XFS extended file attributes.
+type AttributeOperationStats struct {
+	Get    uint32
+	Set    uint32
+	Remove uint32
+	List   uint32
+}
+
+// InodeClusteringStats contains statistics regarding XFS inode clustering
+// operations.
+type InodeClusteringStats struct {
+	Iflush     uint32
+	Flush      uint32
+	FlushInode uint32
+}
+
+// VnodeStats contains statistics regarding XFS vnode operations.
+type VnodeStats struct {
+	Active   uint32
+	Allocate uint32
+	Get      uint32
+	Hold     uint32
+	Release  uint32
+	Reclaim  uint32
+	Remove   uint32
+	Free     uint32
+}
+
+// BufferStats contains statistics regarding XFS read/write I/O buffers.
+type BufferStats struct {
+	Get             uint32
+	Create          uint32
+	GetLocked       uint32
+	GetLockedWaited uint32
+	BusyLocked      uint32
+	MissLocked      uint32
+	PageRetries     uint32
+	PageFound       uint32
+	GetRead         uint32
+}
+
+// ExtendedPrecisionStats contains high precision counters used to track the
+// total number of bytes read, written, or flushed, during XFS operations.
+type ExtendedPrecisionStats struct {
+	FlushBytes uint64
+	WriteBytes uint64
+	ReadBytes  uint64
+}