updated net-test and grafana dashboard to work under ping failure, ma…

…x ping timeout 30s only 1 ping

grafana/dashboards/net-test.json

@@ -94,6 +94,7 @@
       "dashLength": 10,
       "dashes": false,
       "datasource": null,
+      "description": "Count of failed ICMP ping measurements.",
       "fieldConfig": {
         "defaults": {},
         "overrides": []
@@ -135,17 +136,17 @@
       "targets": [
         {
           "exemplar": true,
-          "expr": "ping_failures_total",
+          "expr": "rate(ping_failures_total[1m])",
           "interval": "",
-          "legendFormat": "",
+          "legendFormat": "{{target_host}}",
           "refId": "A"
         }
       ],
       "thresholds": [],
       "timeFrom": null,
       "timeRegions": [],
       "timeShift": null,
-      "title": "Failures",
+      "title": "Ping Failures",
       "tooltip": {
         "shared": true,
         "sort": 0,
@@ -211,6 +212,8 @@
         "alignAsTable": false,
         "avg": false,
         "current": false,
+        "hideEmpty": true,
+        "hideZero": true,
         "max": false,
         "min": false,
         "rightSide": false,
@@ -227,7 +230,7 @@
       "percentage": false,
       "pluginVersion": "7.5.3",
       "pointradius": 2,
-      "points": false,
+      "points": true,
       "renderer": "flot",
       "seriesOverrides": [],
       "spaceLength": 10,
@@ -320,12 +323,12 @@
     "list": []
   },
   "time": {
-    "from": "now-5m",
+    "from": "now-15m",
     "to": "now"
   },
   "timepicker": {},
   "timezone": "",
   "title": "Net Test",
   "uid": "WM-nr_lMk",
-  "version": 7
+  "version": 9
 }

main.go

@@ -13,8 +13,13 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
-const PING_COUNT int = 3
+// PING_COUNT is the number of ping packets sent to determine the average round trip time.
+const PING_COUNT int = 1
 
+// PING_TIMEOUT_MS is the number of milliseconds before a ping attempt will timeout. 30 seconds.
+const PING_TIMEOUT_MS int = 30000
+
+// log is the application logger.
 var log golog.Logger = golog.NewLogger("net-test")
 
 // die will print an error then exit the process with code 1
@@ -133,8 +138,7 @@ func main() {
 				Buckets: []float64{
 					0, 20, 40, 60, 80, 100,
 					150, 200, 500,
-					1000, 1500, 2000, 3000, 5000,
-					10000, 30000, 60000, 120000,
+					1000, 1500, 2000, 3000,
 				},
 			},
 			[]string{"target_host"},
@@ -156,10 +160,15 @@ func main() {
 				pingers := []*ping.Pinger{}
 				for _, host := range targetHosts.Get() {
 					pinger, err := ping.NewPinger(host)
-					check(fmt.Sprintf("failed to create pinger for \"%s\"", host), err)
+					if err != nil {
+						log.Warnf("failed to create pinger for \"%s\": %s", host, err.Error())
+						pingFailures.With(prom.Labels{
+							"target_host": pinger.Addr(),
+						}).Inc()
+					}
 					pinger.Count = PING_COUNT
 					pinger.SetPrivileged(true)
-					pinger.Timeout = time.Duration(120) * time.Second // 2 minute timeout
+					pinger.Timeout = time.Duration(PING_TIMEOUT_MS) * time.Millisecond
 
 					pingers = append(pingers, pinger)
 				}