Improve procstat

closes #799

CHANGELOG.md

@@ -12,6 +12,7 @@
 - [#788](https://github.com/influxdata/telegraf/pull/788): -input-list and -output-list command-line options. Thanks @ebookbug!
 - [#778](https://github.com/influxdata/telegraf/pull/778): Adding a TCP input listener.
 - [#797](https://github.com/influxdata/telegraf/issues/797): Provide option for persistent MQTT consumer client sessions.
+- [#799](https://github.com/influxdata/telegraf/pull/799): Add number of threads for procstat input plugin. Thanks @titilambert!
 
 ### Bugfixes
 - [#748](https://github.com/influxdata/telegraf/issues/748): Fix sensor plugin split on ":"

plugins/inputs/procstat/README.md

@@ -35,6 +35,10 @@ The above configuration would result in output like:
 # Measurements
 Note: prefix can be set by the user, per process.
 
+
+Threads related measurement names:
+- procstat_[prefix_]num_threads value=5
+
 File descriptor related measurement names:
 - procstat_[prefix_]num_fds value=4
 

plugins/inputs/procstat/spec_processor.go

@@ -52,6 +52,7 @@ func NewSpecProcessor(
 }
 
 func (p *SpecProcessor) pushMetrics() {
+	p.pushNThreadsStats()
 	p.pushFDStats()
 	p.pushCtxStats()
 	p.pushIOStats()
@@ -60,6 +61,15 @@ func (p *SpecProcessor) pushMetrics() {
 	p.flush()
 }
 
+func (p *SpecProcessor) pushNThreadsStats() error {
+	numThreads, err := p.proc.NumThreads()
+	if err != nil {
+		return fmt.Errorf("NumThreads error: %s\n", err)
+	}
+	p.add("num_threads", numThreads)
+	return nil
+}
+
 func (p *SpecProcessor) pushFDStats() error {
 	fds, err := p.proc.NumFDs()
 	if err != nil {