Merge pull request #195 from martinlindhe/totals-as-gauges-help-string

Fix wrong metric types in system collector, improve help-strings

README.md

@@ -13,6 +13,7 @@ ad | [Win32_PerfRawData_DirectoryServices_DirectoryServices](https://msdn.micros
 cpu | [Win32_PerfRawData_PerfOS_Processor](https://msdn.microsoft.com/en-us/library/aa394317(v=vs.90).aspx) metrics (cpu usage) | ✓
 cs | [Win32_ComputerSystem](https://msdn.microsoft.com/en-us/library/aa394102) metrics (system properties, num cpus/total memory) | ✓
 dns | [Win32_PerfRawData_DNS_DNS](https://technet.microsoft.com/en-us/library/cc977686.aspx) metrics (DNS Server) |
+hyperv | Performance counters for Hyper-V hosts | 
 iis | [Win32_PerfRawData_W3SVC_WebService](https://msdn.microsoft.com/en-us/library/aa394345) IIS metrics |
 logical_disk | [Win32_PerfRawData_PerfDisk_LogicalDisk](https://msdn.microsoft.com/en-us/windows/hardware/aa394307(v=vs.71)) metrics (disk I/O) | ✓
 net | [Win32_PerfRawData_Tcpip_NetworkInterface](https://technet.microsoft.com/en-us/security/aa394340(v=vs.80)) metrics (network interface I/O) | ✓

collector/system.go

@@ -30,37 +30,37 @@ func NewSystemCollector() (Collector, error) {
 	return &SystemCollector{
 		ContextSwitchesTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "context_switches_total"),
-			"PerfOS_System.ContextSwitchesPersec",
+			"Total number of context switches (WMI source: PerfOS_System.ContextSwitchesPersec)",
 			nil,
 			nil,
 		),
 		ExceptionDispatchesTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "exception_dispatches_total"),
-			"PerfOS_System.ExceptionDispatchesPersec",
+			"Total number of exceptions dispatched (WMI source: PerfOS_System.ExceptionDispatchesPersec)",
 			nil,
 			nil,
 		),
 		ProcessorQueueLength: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "processor_queue_length"),
-			"PerfOS_System.ProcessorQueueLength",
+			"Length of processor queue (WMI source: PerfOS_System.ProcessorQueueLength)",
 			nil,
 			nil,
 		),
 		SystemCallsTotal: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "system_calls_total"),
-			"PerfOS_System.SystemCallsPersec",
+			"Total number of system calls (WMI source: PerfOS_System.SystemCallsPersec)",
 			nil,
 			nil,
 		),
 		SystemUpTime: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "system_up_time"),
-			"SystemUpTime/Frequency_Object",
+			"System boot time (WMI source: PerfOS_System.SystemUpTime)",
 			nil,
 			nil,
 		),
 		Threads: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "threads"),
-			"PerfOS_System.Threads",
+			"Current number of threads (WMI source: PerfOS_System.Threads)",
 			nil,
 			nil,
 		),
@@ -96,12 +96,12 @@ func (c *SystemCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc
 
 	ch <- prometheus.MustNewConstMetric(
 		c.ContextSwitchesTotal,
-		prometheus.GaugeValue,
+		prometheus.CounterValue,
 		float64(dst[0].ContextSwitchesPersec),
 	)
 	ch <- prometheus.MustNewConstMetric(
 		c.ExceptionDispatchesTotal,
-		prometheus.GaugeValue,
+		prometheus.CounterValue,
 		float64(dst[0].ExceptionDispatchesPersec),
 	)
 	ch <- prometheus.MustNewConstMetric(
@@ -111,7 +111,7 @@ func (c *SystemCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc
 	)
 	ch <- prometheus.MustNewConstMetric(
 		c.SystemCallsTotal,
-		prometheus.GaugeValue,
+		prometheus.CounterValue,
 		float64(dst[0].SystemCallsPersec),
 	)
 	ch <- prometheus.MustNewConstMetric(

exporter.go

@@ -44,6 +44,16 @@ var (
 		[]string{"collector"},
 		nil,
 	)
+
+	// This can be removed when client_golang exposes this on Windows
+	// (See https://github.com/prometheus/client_golang/issues/376)
+	startTime = float64(time.Now().Unix())
+	startTimeDesc = prometheus.NewDesc(
+		"process_start_time_seconds",
+		"Start time of the process since unix epoch in seconds.",
+		nil,
+		nil,
+	)
 )
 
 // Describe sends all the descriptors of the collectors included to
@@ -65,6 +75,12 @@ func (coll WmiCollector) Collect(ch chan<- prometheus.Metric) {
 			wg.Done()
 		}(name, c)
 	}
+
+	ch <- prometheus.MustNewConstMetric(
+		startTimeDesc,
+		prometheus.CounterValue,
+		startTime,
+	)
 	wg.Wait()
 }