procstat plugin: store PID as a field

closes #1460

CHANGELOG.md

@@ -49,6 +49,7 @@ should now look like:
 - [#1334](https://github.com/influxdata/telegraf/issues/1334): Prometheus output, metric refresh and caching fixes.
 - [#1432](https://github.com/influxdata/telegraf/issues/1432): Panic fix for multiple graphite outputs under very high load.
 - [#1412](https://github.com/influxdata/telegraf/pull/1412): Instrumental output has better reconnect behavior
+- [#1460](https://github.com/influxdata/telegraf/issues/1460): Remove PID from procstat plugin to fix cardinality issues.
 
 ## v1.0 beta 2 [2016-06-21]
 

plugins/inputs/procstat/procstat.go

@@ -70,7 +70,7 @@ func (p *Procstat) Gather(acc telegraf.Accumulator) error {
 			p.Exe, p.PidFile, p.Pattern, p.User, err.Error())
 	} else {
 		for pid, proc := range p.pidmap {
-			p := NewSpecProcessor(p.ProcessName, p.Prefix, acc, proc, p.tagmap[pid])
+			p := NewSpecProcessor(p.ProcessName, p.Prefix, pid, acc, proc, p.tagmap[pid])
 			p.pushMetrics()
 		}
 	}
@@ -140,7 +140,6 @@ func (p *Procstat) pidsFromFile() ([]int32, error) {
 			out = append(out, int32(pid))
 			p.tagmap[int32(pid)] = map[string]string{
 				"pidfile": p.PidFile,
-				"pid":     strings.TrimSpace(string(pidString)),
 			}
 		}
 	}
@@ -165,7 +164,6 @@ func (p *Procstat) pidsFromExe() ([]int32, error) {
 				out = append(out, int32(ipid))
 				p.tagmap[int32(ipid)] = map[string]string{
 					"exe": p.Exe,
-					"pid": pid,
 				}
 			} else {
 				outerr = err
@@ -193,7 +191,6 @@ func (p *Procstat) pidsFromPattern() ([]int32, error) {
 				out = append(out, int32(ipid))
 				p.tagmap[int32(ipid)] = map[string]string{
 					"pattern": p.Pattern,
-					"pid":     pid,
 				}
 			} else {
 				outerr = err
@@ -221,7 +218,6 @@ func (p *Procstat) pidsFromUser() ([]int32, error) {
 				out = append(out, int32(ipid))
 				p.tagmap[int32(ipid)] = map[string]string{
 					"user": p.User,
-					"pid":  pid,
 				}
 			} else {
 				outerr = err

plugins/inputs/procstat/spec_processor.go

@@ -10,6 +10,7 @@ import (
 
 type SpecProcessor struct {
 	Prefix string
+	pid    int32
 	tags   map[string]string
 	fields map[string]interface{}
 	acc    telegraf.Accumulator
@@ -19,6 +20,7 @@ type SpecProcessor struct {
 func NewSpecProcessor(
 	processName string,
 	prefix string,
+	pid int32,
 	acc telegraf.Accumulator,
 	p *process.Process,
 	tags map[string]string,
@@ -33,6 +35,7 @@ func NewSpecProcessor(
 	}
 	return &SpecProcessor{
 		Prefix: prefix,
+		pid:    pid,
 		tags:   tags,
 		fields: make(map[string]interface{}),
 		acc:    acc,
@@ -45,7 +48,7 @@ func (p *SpecProcessor) pushMetrics() {
 	if p.Prefix != "" {
 		prefix = p.Prefix + "_"
 	}
-	fields := map[string]interface{}{}
+	fields := map[string]interface{}{"pid": p.pid}
 
 	numThreads, err := p.proc.NumThreads()
 	if err == nil {