Merge pull request #146 from KevinPike/memstats

memstats collection

prometheus/go_collector.go

@@ -1,6 +1,7 @@
 package prometheus
 
 import (
+	"fmt"
 	"runtime"
 	"runtime/debug"
 	"time"
@@ -9,6 +10,9 @@ import (
 type goCollector struct {
 	goroutines Gauge
 	gcDesc     *Desc
+
+	// metrics to describe and collect
+	metrics memStatsMetrics
 }
 
 // NewGoCollector returns a collector which exports metrics about the current
@@ -16,20 +20,216 @@ type goCollector struct {
 func NewGoCollector() *goCollector {
 	return &goCollector{
 		goroutines: NewGauge(GaugeOpts{
-			Name: "go_goroutines",
+			Namespace: "go",
+			Name:      "goroutines",
 			Help:      "Number of goroutines that currently exist.",
 		}),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
 			"A summary of the GC invocation durations.",
 			nil, nil),
+		metrics: memStatsMetrics{
+			{
+				desc: NewDesc(
+					memstatNamespace("alloc_bytes"),
+					"Number of bytes allocated and still in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("alloc_bytes_total"),
+					"Total number of bytes allocated, even if freed.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("sys_bytes"),
+					"Number of bytes obtained by system. Sum of all system allocations.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("lookups_total"),
+					"Total number of pointer lookups.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mallocs_total"),
+					"Total number of mallocs.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("frees_total"),
+					"Total number of frees.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_alloc_bytes"),
+					"Number of heap bytes allocated and still in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_sys_bytes"),
+					"Number of heap bytes obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_idle_bytes"),
+					"Number of heap bytes waiting to be used.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_inuse_bytes"),
+					"Number of heap bytes that are in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_released_bytes_total"),
+					"Total number of heap bytes released to OS.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_objects"),
+					"Number of allocated objects.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("stack_inuse_bytes"),
+					"Number of bytes in use by the stack allocator.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("stack_sys_bytes"),
+					"Number of bytes obtained from system for stack allocator.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mspan_inuse_bytes"),
+					"Number of bytes in use by mspan structures.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mspan_sys_bytes"),
+					"Number of bytes used for mspan structures obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mcache_inuse_bytes"),
+					"Number of bytes in use by mcache structures.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mcache_sys_bytes"),
+					"Number of bytes used for mcache structures obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("buck_hash_sys_bytes"),
+					"Number of bytes used by the profiling bucket hash table.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("gc_sys_bytes"),
+					"Number of bytes used for garbage collection system metadata.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("other_sys_bytes"),
+					"Number of bytes used for other system allocations.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("next_gc_bytes"),
+					"Number of heap bytes when next garbage collection will take place.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("last_gc_time_seconds"),
+					"Number of seconds since 1970 of last garbage collection.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.LastGC*10 ^ 9) },
+				valType: GaugeValue,
+			},
+		},
 	}
 }
 
+func memstatNamespace(s string) string {
+	return fmt.Sprintf("go_memstats_%s", s)
+}
+
 // Describe returns all descriptions of the collector.
 func (c *goCollector) Describe(ch chan<- *Desc) {
 	ch <- c.goroutines.Desc()
 	ch <- c.gcDesc
+
+	for _, i := range c.metrics {
+		ch <- i.desc
+	}
 }
 
 // Collect returns the current state of all metrics of the collector.
@@ -47,4 +247,17 @@ func (c *goCollector) Collect(ch chan<- Metric) {
 	}
 	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
 	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles)
+
+	ms := &runtime.MemStats{}
+	runtime.ReadMemStats(ms)
+	for _, i := range c.metrics {
+		ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
+	}
+}
+
+// memStatsMetrics provide description, value, and value type for memstat metrics.
+type memStatsMetrics []struct {
+	desc    *Desc
+	eval    func(*runtime.MemStats) float64
+	valType ValueType
 }