Add garbage collection stats

This commit is contained in:
Oliver 2015-04-30 00:27:14 -04:00
parent 6efaf95d98
commit ff586eaac1
2 changed files with 68 additions and 3 deletions

View File

@ -2,10 +2,12 @@ package prometheus
import (
"runtime"
"runtime/debug"
)
type goCollector struct {
goroutines Gauge
gcDesc *Desc
}
// NewGoCollector returns a collector which exports metrics about the current
@ -16,16 +18,26 @@ func NewGoCollector() *goCollector {
Name: "process_goroutines",
Help: "Number of goroutines that currently exist.",
}),
gcDesc: NewDesc(
"go_gc_duration_seconds",
"A summary of the GC invocation durations.",
nil, nil),
}
}
// Describe returns all descriptions of the collector.
func (c *goCollector) Describe(ch chan<- *Desc) {
ch <- c.goroutines.Desc()
ch <- c.gcDesc
}
// Collect returns the current state of all metrics of the collector.
func (c *goCollector) Collect(ch chan<- Metric) {
c.goroutines.Set(float64(runtime.NumGoroutine()))
ch <- c.goroutines
var stats debug.GCStats
debug.ReadGCStats(&stats)
ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), nil)
}

View File

@ -1,7 +1,7 @@
package prometheus
import (
"reflect"
"runtime/debug"
"testing"
"time"
@ -35,6 +35,9 @@ func TestGoCollector(t *testing.T) {
case Gauge:
pb := &dto.Metric{}
m.Write(pb)
if pb.GetGauge() == nil {
continue
}
if old == -1 {
old = int(pb.GetGauge().GetValue())
@ -48,8 +51,58 @@ func TestGoCollector(t *testing.T) {
}
return
default:
t.Errorf("want type Gauge, got %s", reflect.TypeOf(metric))
}
case <-time.After(1 * time.Second):
t.Fatalf("expected collect timed out")
}
}
}
func TestGCCollector(t *testing.T) {
var (
c = NewGoCollector()
ch = make(chan Metric)
waitc = make(chan struct{})
closec = make(chan struct{})
oldGC uint64
oldPause float64
)
defer close(closec)
go func() {
c.Collect(ch)
// force GC
debug.FreeOSMemory()
<-waitc
c.Collect(ch)
}()
first := true
for {
select {
case metric := <-ch:
switch m := metric.(type) {
case *constSummary, *value:
pb := &dto.Metric{}
m.Write(pb)
if pb.GetSummary() == nil {
continue
}
if first {
first = false
oldGC = *pb.GetSummary().SampleCount
oldPause = *pb.GetSummary().SampleSum
close(waitc)
continue
}
if diff := *pb.GetSummary().SampleCount - oldGC; diff != 1 {
t.Errorf("want 1 new garbage collection run, got %d", diff)
}
if diff := *pb.GetSummary().SampleSum - oldPause; diff <= 0 {
t.Errorf("want moar pause, got %f", diff)
}
return
}
case <-time.After(1 * time.Second):
t.Fatalf("expected collect timed out")