Merge pull request #394 from martinlindhe/fix-cgo-build-tag

Remove cgo build tag from container collector

README.md

@@ -17,6 +17,7 @@ Name     | Description | Enabled by default
 [hyperv](docs/collector.hyperv.md) | Hyper-V hosts |
 [iis](docs/collector.iis.md) | IIS sites and applications |
 [logical_disk](docs/collector.logical_disk.md) | Logical disks, disk I/O | ✓
+[logon](docs/collector.logon.md) | User logon sessions |
 [memory](docs/collector.memory.md) | Memory usage metrics |
 [msmq](docs/collector.msmq.md) | MSMQ queues |
 [mssql](docs/collector.mssql.md) | [SQL Server Performance Objects](https://docs.microsoft.com/en-us/sql/relational-databases/performance-monitor/use-sql-server-objects#SQLServerPOs) metrics  |

collector/container.go

@@ -1,4 +1,4 @@
-// +build windows,cgo
+// +build windows
 
 package collector
 

collector/logical_disk.go

@@ -29,17 +29,20 @@ var (
 
 // A LogicalDiskCollector is a Prometheus collector for WMI Win32_PerfRawData_PerfDisk_LogicalDisk metrics
 type LogicalDiskCollector struct {
-	RequestsQueued  *prometheus.Desc
+	RequestsQueued   *prometheus.Desc
-	ReadBytesTotal  *prometheus.Desc
+	ReadBytesTotal   *prometheus.Desc
-	ReadsTotal      *prometheus.Desc
+	ReadsTotal       *prometheus.Desc
-	WriteBytesTotal *prometheus.Desc
+	WriteBytesTotal  *prometheus.Desc
-	WritesTotal     *prometheus.Desc
+	WritesTotal      *prometheus.Desc
-	ReadTime        *prometheus.Desc
+	ReadTime         *prometheus.Desc
-	WriteTime       *prometheus.Desc
+	WriteTime        *prometheus.Desc
-	TotalSpace      *prometheus.Desc
+	TotalSpace       *prometheus.Desc
-	FreeSpace       *prometheus.Desc
+	FreeSpace        *prometheus.Desc
-	IdleTime        *prometheus.Desc
+	IdleTime         *prometheus.Desc
-	SplitIOs        *prometheus.Desc
+	SplitIOs         *prometheus.Desc
+	ReadLatency      *prometheus.Desc
+	WriteLatency     *prometheus.Desc
+	ReadWriteLatency *prometheus.Desc
 
 	volumeWhitelistPattern *regexp.Regexp
 	volumeBlacklistPattern *regexp.Regexp
@@ -127,6 +130,27 @@ func NewLogicalDiskCollector() (Collector, error) {
 			nil,
 		),
 
+		ReadLatency: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "read_latency_seconds_total"),
+			"Shows the average time, in seconds, of a read operation from the disk (LogicalDisk.AvgDiskSecPerRead)",
+			[]string{"volume"},
+			nil,
+		),
+
+		WriteLatency: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "write_latency_seconds_total"),
+			"Shows the average time, in seconds, of a write operation to the disk (LogicalDisk.AvgDiskSecPerWrite)",
+			[]string{"volume"},
+			nil,
+		),
+
+		ReadWriteLatency: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "read_write_latency_seconds_total"),
+			"Shows the time, in seconds, of the average disk transfer (LogicalDisk.AvgDiskSecPerTransfer)",
+			[]string{"volume"},
+			nil,
+		),
+
 		volumeWhitelistPattern: regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *volumeWhitelist)),
 		volumeBlacklistPattern: regexp.MustCompile(fmt.Sprintf("^(?:%s)$", *volumeBlacklist)),
 	}, nil
@@ -158,6 +182,9 @@ type Win32_PerfRawData_PerfDisk_LogicalDisk struct {
 	PercentFreeSpace_Base  uint32
 	PercentIdleTime        uint64
 	SplitIOPerSec          uint32
+	AvgDiskSecPerRead      uint64
+	AvgDiskSecPerWrite     uint64
+	AvgDiskSecPerTransfer  uint64
 }
 
 func (c *LogicalDiskCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
@@ -250,6 +277,27 @@ func (c *LogicalDiskCollector) collect(ch chan<- prometheus.Metric) (*prometheus
 			float64(volume.SplitIOPerSec),
 			volume.Name,
 		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.ReadLatency,
+			prometheus.CounterValue,
+			float64(volume.AvgDiskSecPerRead),
+			volume.Name,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.WriteLatency,
+			prometheus.CounterValue,
+			float64(volume.AvgDiskSecPerWrite),
+			volume.Name,
+		)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.ReadWriteLatency,
+			prometheus.CounterValue,
+			float64(volume.AvgDiskSecPerTransfer),
+			volume.Name,
+		)
 	}
 
 	return nil, nil

collector/logon.go

@@ -0,0 +1,199 @@
+// +build windows
+
+package collector
+
+import (
+	"errors"
+
+	"github.com/StackExchange/wmi"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
+)
+
+func init() {
+	Factories["logon"] = NewLogonCollector
+}
+
+// A LogonCollector is a Prometheus collector for WMI metrics
+type LogonCollector struct {
+	LogonType *prometheus.Desc
+}
+
+// NewLogonCollector ...
+func NewLogonCollector() (Collector, error) {
+	const subsystem = "logon"
+
+	return &LogonCollector{
+		LogonType: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "logon_type"),
+			"Number of active logon sessions (LogonSession.LogonType)",
+			[]string{"status"},
+			nil,
+		),
+	}, nil
+}
+
+// Collect sends the metric values for each metric
+// to the provided prometheus Metric channel.
+func (c *LogonCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) error {
+	if desc, err := c.collect(ch); err != nil {
+		log.Error("failed collecting user metrics:", desc, err)
+		return err
+	}
+	return nil
+}
+
+// Win32_LogonSession docs:
+// - https://docs.microsoft.com/en-us/windows/win32/cimwin32prov/win32-logonsession
+type Win32_LogonSession struct {
+	LogonType uint32
+}
+
+func (c *LogonCollector) collect(ch chan<- prometheus.Metric) (*prometheus.Desc, error) {
+	var dst []Win32_LogonSession
+	q := queryAll(&dst)
+	if err := wmi.Query(q, &dst); err != nil {
+		return nil, err
+	}
+	if len(dst) == 0 {
+		return nil, errors.New("WMI query returned empty result set")
+	}
+
+	// Init counters
+	system := 0
+	interactive := 0
+	network := 0
+	batch := 0
+	service := 0
+	proxy := 0
+	unlock := 0
+	networkcleartext := 0
+	newcredentials := 0
+	remoteinteractive := 0
+	cachedinteractive := 0
+	cachedremoteinteractive := 0
+	cachedunlock := 0
+
+	for _, entry := range dst {
+		switch entry.LogonType {
+		case 0:
+			system++
+		case 2:
+			interactive++
+		case 3:
+			network++
+		case 4:
+			batch++
+		case 5:
+			service++
+		case 6:
+			proxy++
+		case 7:
+			unlock++
+		case 8:
+			networkcleartext++
+		case 9:
+			newcredentials++
+		case 10:
+			remoteinteractive++
+		case 11:
+			cachedinteractive++
+		case 12:
+			cachedremoteinteractive++
+		case 13:
+			cachedunlock++
+		}
+	}
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(system),
+		"system",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(interactive),
+		"interactive",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(network),
+		"network",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(batch),
+		"batch",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(service),
+		"service",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(proxy),
+		"proxy",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(unlock),
+		"unlock",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(networkcleartext),
+		"network_clear_text",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(newcredentials),
+		"new_credentials",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(remoteinteractive),
+		"remote_interactive",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(cachedinteractive),
+		"cached_interactive",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(remoteinteractive),
+		"cached_remote_interactive",
+	)
+
+	ch <- prometheus.MustNewConstMetric(
+		c.LogonType,
+		prometheus.GaugeValue,
+		float64(cachedunlock),
+		"cached_unlock",
+	)
+	return nil, nil
+}

docs/README.md

@@ -9,6 +9,7 @@ This directory contains documentation of the collectors in the WMI exporter, wit
 - [`hyperv`](collector.hyperv.md)
 - [`iis`](collector.iis.md)
 - [`logical_disk`](collector.logical_disk.md)
+- [`logon`](collector.logon.md)
 - [`memory`](collector.memory.md)
 - [`msmq`](collector.msmq.md)
 - [`mssql`](collector.mssql.md)

docs/collector.cpu.md

@@ -34,10 +34,27 @@ Name | Description | Type | Labels
 `wmi_cpu_processor_performance` | Processor Performance is the average performance of the processor while it is executing instructions, as a percentage of the nominal performance of the processor. On some processors, Processor Performance may exceed 100% | `gauge`
 
 ### Example metric
-_This collector does not yet have explained examples, we would appreciate your help adding them!_
+Show frequency of host CPU cores
+```
+wmi_cpu_core_frequency_mhz{instance="localhost"}
+```
 
 ## Useful queries
-_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+Show cpu usage by mode.
+```
+sum by (mode) (irate(wmi_cpu_time_total{instance="localhost"}[5m]))
+```
 
 ## Alerting examples
-_This collector does not yet have alerting examples, we would appreciate your help adding them!_
+**prometheus.rules**
+```
+# Alert on hosts with more than 80% CPU usage over a 10 minute period
+- alert: CpuUsage
+  expr: 100 - (avg by (instance) (irate(wmi_cpu_time_total{mode="idle"}[2m])) * 100) > 80
+  for: 10m
+  labels:
+    severity: warning
+  annotations:
+    summary: "CPU Usage (instance {{ $labels.instance }})"
+    description: "CPU Usage is more than 80%\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"
+```

docs/collector.logical_disk.md

@@ -22,23 +22,54 @@ If given, a disk needs to *not* match the blacklist regexp in order for the corr
 
 Name | Description | Type | Labels
 -----|-------------|------|-------
-`requests_queued` | _Not yet documented_ | gauge | `volume`
+`requests_queued` | Number of requests outstanding on the disk at the time the performance data is collected | gauge | `volume`
-`read_bytes_total` | _Not yet documented_ | counter | `volume`
+`read_bytes_total` | Rate at which bytes are transferred from the disk during read operations | counter | `volume`
-`reads_total` | _Not yet documented_ | counter | `volume`
+`reads_total` | Rate of read operations on the disk | counter | `volume`
-`write_bytes_total` | _Not yet documented_ | counter | `volume`
+`write_bytes_total` | Rate at which bytes are transferred to the disk during write operations  | counter | `volume`
-`writes_total` | _Not yet documented_ | counter | `volume`
+`writes_total` | Rate of write operations on the disk  | counter | `volume`
-`read_seconds_total` | _Not yet documented_ | counter | `volume`
+`read_seconds_total` | Seconds the disk was busy servicing read requests | counter | `volume`
-`write_seconds_total` | _Not yet documented_ | counter | `volume`
+`write_seconds_total` | Seconds the disk was busy servicing write requests | counter | `volume`
-`free_bytes` | _Not yet documented_ | gauge | `volume`
+`free_bytes` | Unused space of the disk in bytes | gauge | `volume`
-`size_bytes` | _Not yet documented_ | gauge | `volume`
+`size_bytes` | Total size of the disk in bytes | gauge | `volume`
-`idle_seconds_total` | _Not yet documented_ | counter | `volume`
+`idle_seconds_total` | Seconds the disk was idle (not servicing read/write requests) | counter | `volume`
-`split_ios_total` | _Not yet documented_ | counter | `volume`
+`split_ios_total` | Number of I/Os to the disk split into multiple I/Os | counter | `volume`
 
 ### Example metric
-_This collector does not yet have explained examples, we would appreciate your help adding them!_
+Query the rate of write operations to a disk
+```
+rate(wmi_logical_disk_read_bytes_total{instance="localhost", volume=~"C:"}[2m])
+```
 
 ## Useful queries
-_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+Calculate rate of total IOPS for disk
+```
+rate(wmi_logical_disk_reads_total{instance="localhost", volume="C:"}[2m]) + rate(wmi_logical_disk_writes_total{instance="localhost", volume="C:"}[2m])
+```
 
 ## Alerting examples
-_This collector does not yet have alerting examples, we would appreciate your help adding them!_
+**prometheus.rules**
+```
+groups:
+- name: Windows Disk Alerts
+  rules:
+
+  # Sends an alert when disk space usage is above 95%
+  - alert: DiskSpaceUsage
+    expr: 100.0 - 100 * (wmi_logical_disk_free_bytes / wmi_logical_disk_size_bytes) > 95
+    for: 10m
+    labels:
+      severity: high
+    annotations:
+      summary: "Disk Space Usage (instance {{ $labels.instance }})"
+      description: "Disk Space on Drive is used more than 95%\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"
+
+  # Alerts on disks with over 85% space usage predicted to fill within the next four days
+  - alert: DiskFilling
+    expr: 100 * (wmi_logical_disk_free_bytes / wmi_logical_disk_size_bytes) < 15 and predict_linear(wmi_logical_disk_free_bytes[6h], 4 * 24 * 3600) < 0
+    for: 10m
+    labels:
+      severity: warning
+    annotations:
+      summary: "Disk full in four days (instance {{ $labels.instance }})"
+      description: "{{ $labels.volume }} is expected to fill up within four days. Currently {{ $value | humanize }}% is available.\n VALUE = {{ $value }}\n LABELS: {{ $labels }}"
+```

docs/collector.logon.md

@@ -0,0 +1,34 @@
+# logon collector
+
+The logon collector exposes metrics detailing the active user logon sessions.
+
+|||
+-|-
+Metric name prefix  | `logon`
+Classes             | [`Win32_LogonSession`](https://docs.microsoft.com/en-us/windows/win32/cimwin32prov/win32-logonsession)
+Enabled by default? | No
+
+## Flags
+
+None
+
+## Metrics
+
+Name | Description | Type | Labels
+-----|-------------|------|-------
+`wmi_logon_logon_type` | Number of active user logon sessions | gauge | status
+
+### Example metric
+Query the total number of interactive logon sessions
+```
+wmi_logon_logon_type{status="interactive"}
+```
+
+## Useful queries
+Query the total number of local and remote (I.E. Terminal Services) interactive sessions.
+```
+wmi_logon_logon_type{status=~"interactive|remoteinteractive"}
+```
+
+## Alerting examples
+_This collector does not yet have alerting examples, we would appreciate your help adding them!_

docs/collector.memory.md

@@ -19,25 +19,25 @@ Name | Description | Type | Labels
 `wmi_cs_logical_processors` | Number of installed logical processors | gauge | None
 `wmi_cs_physical_memory_bytes` | Total installed physical memory | gauge | None
 `wmi_memory_available_bytes` | The amount of physical memory immediately available for allocation to a process or for system use. It is equal to the sum of memory assigned to the standby (cached), free and zero page lists | gauge | None
-`wmi_memory_cache_bytes` | _Not yet documented_ | gauge | None
+`wmi_memory_cache_bytes` | Number of bytes currently being used by the file system cache | gauge | None
-`wmi_memory_cache_bytes_peak` | _Not yet documented_ | gauge | None
+`wmi_memory_cache_bytes_peak` | Maximum number of CacheBytes after the system was last restarted | gauge | None
-`wmi_memory_cache_faults_total` | _Not yet documented_ | gauge | None
+`wmi_memory_cache_faults_total` | Number of faults which occur when a page sought in the file system cache is not found there and must be retrieved from elsewhere in memory (soft fault) or from disk (hard fault) | gauge | None
-`wmi_memory_commit_limit` | _Not yet documented_ | gauge | None
+`wmi_memory_commit_limit` | Amount of virtual memory, in bytes, that can be committed without having to extend the paging file(s) | gauge | None
-`wmi_memory_committed_bytes` | _Not yet documented_ | gauge | None
+`wmi_memory_committed_bytes` | Amount of committed virtual memory, in bytes | gauge | None
 `wmi_memory_demand_zero_faults_total` | The number of zeroed pages required to satisfy faults. Zeroed pages, pages emptied of previously stored data and filled with zeros, are a security feature of Windows that prevent processes from seeing data stored by earlier processes that used the memory space | gauge | None
 `wmi_memory_free_and_zero_page_list_bytes` | _Not yet documented_ | gauge | None
-`wmi_memory_free_system_page_table_entries` | _Not yet documented_ | gauge | None
+`wmi_memory_free_system_page_table_entries` | Number of page table entries not being used by the system | gauge | None
 `wmi_memory_modified_page_list_bytes` | _Not yet documented_ | gauge | None
-`wmi_memory_page_faults_total` | _Not yet documented_ | gauge | None
+`wmi_memory_page_faults_total` | Overall rate at which faulted pages are handled by the processor | gauge | None
 `wmi_memory_swap_page_reads_total` | Number of disk page reads (a single read operation reading several pages is still only counted once) | gauge | None
 `wmi_memory_swap_pages_read_total` | Number of pages read across all page reads (ie counting all pages read even if they are read in a single operation) | gauge | None
 `wmi_memory_swap_pages_written_total` | Number of pages written across all page writes (ie counting all pages written even if they are written in a single operation) | gauge | None
 `wmi_memory_swap_page_operations_total` | Total number of swap page read and writes (PagesPersec) | gauge | None
 `wmi_memory_swap_page_writes_total` | Number of disk page writes (a single write operation writing several pages is still only counted once) | gauge | None
 `wmi_memory_pool_nonpaged_allocs_total` | The number of calls to allocate space in the nonpaged pool. The nonpaged pool is an area of system memory area for objects that cannot be written to disk, and must remain in physical memory as long as they are allocated | gauge | None
-`wmi_memory_pool_nonpaged_bytes_total` | _Not yet documented_ | gauge | None
+`wmi_memory_pool_nonpaged_bytes_total` | Number of bytes in the non-paged pool | gauge | None
-`wmi_memory_pool_paged_allocs_total` | _Not yet documented_ | gauge | None
+`wmi_memory_pool_paged_allocs_total` | Number of calls to allocate space in the paged pool, regardless of the amount of space allocated in each call | gauge | None
-`wmi_memory_pool_paged_bytes` | _Not yet documented_ | gauge | None
+`wmi_memory_pool_paged_bytes` | Number of bytes in the paged pool | gauge | None
 `wmi_memory_pool_paged_resident_bytes` | _Not yet documented_ | gauge | None
 `wmi_memory_standby_cache_core_bytes` | _Not yet documented_ | gauge | None
 `wmi_memory_standby_cache_normal_priority_bytes` | _Not yet documented_ | gauge | None

docs/collector.net.md

@@ -22,24 +22,40 @@ If given, an interface name needs to *not* match the blacklist regexp in order f
 
 Name | Description | Type | Labels
 -----|-------------|------|-------
-`wmi_net_bytes_received_total` | _Not yet documented_ | counter | `nic`
+`wmi_net_bytes_received_total` | Total bytes received by interface | counter | `nic`
-`wmi_net_bytes_sent_total` | _Not yet documented_ | counter | `nic`
+`wmi_net_bytes_sent_total` | Total bytes transmitted by interface | counter | `nic`
-`wmi_net_bytes_total` | _Not yet documented_ | counter | `nic`
+`wmi_net_bytes_total` | Total bytes received and transmitted by interface | counter | `nic`
-`wmi_net_packets_outbound_discarded` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_outbound_discarded` | Total outbound packets that were chosen to be discarded even though no errors had been detected to prevent transmission | counter | `nic`
-`wmi_net_packets_outbound_errors` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_outbound_errors` | Total packets that could not be transmitted due to errors | counter | `nic`
-`wmi_net_packets_received_discarded` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_received_discarded` | Total inbound packets that were chosen to be discarded even though no errors had been detected to prevent delivery | counter | `nic`
-`wmi_net_packets_received_errors` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_received_errors` | Total packets that could not be received due to errors  | counter | `nic`
-`wmi_net_packets_received_total` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_received_total` | Total packets received by interface | counter | `nic`
-`wmi_net_packets_received_unknown` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_received_unknown` | Total packets received by interface that were discarded because of an unknown or unsupported protocol | counter | `nic`
-`wmi_net_packets_total` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_total` | Total packets received and transmitted by interface | counter | `nic`
-`wmi_net_packets_sent_total` | _Not yet documented_ | counter | `nic`
+`wmi_net_packets_sent_total` | Total packets transmitted by interface | counter | `nic`
-`wmi_net_current_bandwidth` | _Not yet documented_ | counter | `nic`
+`wmi_net_current_bandwidth` | Estimate of the interface's current bandwidth in bits per second (bps) | counter | `nic`
 
 ### Example metric
-_This collector does not yet have explained examples, we would appreciate your help adding them!_
+Query the rate of transmitted network traffic
+```
+rate(wmi_net_bytes_sent_total{instance="localhost"}[2m])
+```
 
 ## Useful queries
-_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+Get total utilisation of network interface as a percentage
+```
+rate(wmi_net_bytes_total{instance="localhost", nic="Microsoft_Hyper_V_Network_Adapter__1"}[2m]) * 8 / wmi_net_current_bandwidth{instance="locahost", nic="Microsoft_Hyper_V_Network_Adapter__1"} * 100
+```
 
 ## Alerting examples
-_This collector does not yet have alerting examples, we would appreciate your help adding them!_
+**prometheus.rules**
+```
+- alert: NetInterfaceUsage
+  expr: rate(wmi_net_bytes_total[2m]) * 8 / wmi_net_current_bandwidth * 100 > 90
+  for: 10m
+  labels:
+    severity: high
+  annotations:
+    summary: "Network Interface Usage (instance {{ $labels.instance }})"
+    description: "Network traffic usage is greater than 95% for interface {{ $labels.nic }}\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"
+```

docs/collector.system.md

@@ -16,18 +16,24 @@ None
 
 Name | Description | Type | Labels
 -----|-------------|------|-------
-`wmi_system_context_switches_total` | _Not yet documented_ | counter | None
+`wmi_system_context_switches_total` | Total number of [context switches](https://en.wikipedia.org/wiki/Context_switch) | counter | None
-`wmi_system_exception_dispatches_total` | _Not yet documented_ | counter | None
+`wmi_system_exception_dispatches_total` | Total exceptions dispatched by the system | counter | None
-`wmi_system_processor_queue_length` | _Not yet documented_ | gauge | None
+`wmi_system_processor_queue_length` | Number of threads in the processor queue. There is a single queue for processor time even on computers with multiple processors. | gauge | None
-`wmi_system_system_calls_total` | _Not yet documented_ | counter | None
+`wmi_system_system_calls_total` | Total combined calls to Windows NT system service routines by all processes running on the computer | counter | None
-`wmi_system_system_up_time` | _Not yet documented_ | gauge | None
+`wmi_system_system_up_time` | Time of last boot of system | gauge | None
-`wmi_system_threads` | _Not yet documented_ | gauge | None
+`wmi_system_threads` | Number of Windows system [threads](https://en.wikipedia.org/wiki/Thread_(computing)) | gauge | None
 
 ### Example metric
-_This collector does not yet have explained examples, we would appreciate your help adding them!_
+Show current number of system threads
+```
+wmi_system_threads{instance="localhost"}
+```
 
 ## Useful queries
-_This collector does not yet have any useful queries added, we would appreciate your help adding them!_
+Find hosts that have rebooted in the last 24 hours
+```
+time() - wmi_system_system_up_time < 86400
+```
 
 ## Alerting examples
 _This collector does not yet have alerting examples, we would appreciate your help adding them!_

exporter.go

@@ -5,6 +5,7 @@ package main
 import (
 	"fmt"
 	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"sort"
 	"strconv"
@@ -144,6 +145,7 @@ func (coll WmiCollector) Collect(ch chan<- prometheus.Metric) {
 	go func() {
 		wg.Wait()
 		close(allDone)
+		close(metricsBuffer)
 	}()
 
 	// Wait until either all collectors finish, or timeout expires