Ignore NaN values in collection.

We'll re-enable it when we have a better way in UI to handle these.

collector/prometheus_collector.go

@@ -17,6 +17,7 @@ package collector
 import (
 	"encoding/json"
 	"io/ioutil"
+	"math"
 	"net/http"
 	"strconv"
 	"strings"
@@ -153,6 +154,9 @@ func (collector *PrometheusCollector) Collect(metrics map[string][]v1.MetricVal)
 			if err != nil {
 				errorSlice = append(errorSlice, err)
 			}
+			if math.IsNaN(metVal) {
+				metVal = 0
+			}
 
 			metric := v1.MetricVal{
 				Label:      metLabel,