use counters where applicable, improve descriptions

prometheus/go_collector.go

@@ -9,9 +9,20 @@ import (
 )
 
 type goCollector struct {
-	*memStatsCollector
 	goroutines   Gauge
 	gcDesc       *Desc
+	alloc        prometheus.Gauge
+	totalAlloc   prometheus.Gauge
+	sys          prometheus.Gauge
+	lookups      prometheus.Gauge
+	mallocs      prometheus.Gauge
+	frees        prometheus.Gauge
+	heapAlloc    prometheus.Gauge
+	heapSys      prometheus.Gauge
+	heapIdle     prometheus.Gauge
+	heapInuse    prometheus.Gauge
+	heapReleased prometheus.Gauge
+	heapObjects  prometheus.Gauge
 }
 
 // NewGoCollector returns a collector which exports metrics about the current
@@ -26,7 +37,78 @@ func NewGoCollector() *goCollector {
 			"go_gc_duration_seconds",
 			"A summary of the GC invocation durations.",
 			nil, nil),
-		memStatsCollector: newMemStatsCollector(),
+		alloc: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "alloc_bytes",
+			Help:      "Number of bytes allocated and still in use.",
+		}),
+		totalAlloc: prometheus.NewCounter(prometheus.CounterOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "alloc_bytes_total",
+			Help:      "Total number of bytes allocated, even if freed.",
+		}),
+		sys: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "sys_bytes",
+			Help:      "Number of bytes obtained from system",
+		}),
+		lookups: prometheus.NewCounter(prometheus.CounterOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "lookups_total",
+			Help:      "Total number of pointer lookups.",
+		}),
+		mallocs: prometheus.NewCounter(prometheus.CounterOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "mallocs_total",
+			Help:      "Total number of mallocs.",
+		}),
+		frees: prometheus.NewCounter(prometheus.CounterOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "frees_total",
+			Help:      "Total number of frees.",
+		}),
+		heapAlloc: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "heap_alloc_bytes",
+			Help:      "Number heap bytes allocated and still in use.",
+		}),
+		heapSys: prometheus.NewCounter(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "heap_sys_bytes",
+			Help:      "Total bytes in heap obtained from system.",
+		}),
+		heapIdle: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "heap_idle_bytes",
+			Help:      "Number bytes in heap waiting to be used.",
+		}),
+		heapInuse: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "heap_inuse_bytes",
+			Help:      "Number of bytes in heap that are in use.",
+		}),
+		heapReleased: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "heap_released_bytes",
+			Help:      "Number of bytes in heap released to OS.",
+		}),
+		heapObjects: prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "go",
+			Subsystem: "memstats",
+			Name:      "heap_objects",
+			Help:      "Number of allocated objects.",
+		}),
 	}
 }
 
@@ -34,6 +116,18 @@ func NewGoCollector() *goCollector {
 func (c *goCollector) Describe(ch chan<- *Desc) {
 	ch <- c.goroutines.Desc()
 	ch <- c.gcDesc
+	ch <- m.alloc.Desc()
+	ch <- m.totalAlloc.Desc()
+	ch <- m.sys.Desc()
+	ch <- m.lookups.Desc()
+	ch <- m.mallocs.Desc()
+	ch <- m.frees.Desc()
+	ch <- m.heapAlloc.Desc()
+	ch <- m.heapSys.Desc()
+	ch <- m.heapIdle.Desc()
+	ch <- m.heapInuse.Desc()
+	ch <- m.heapReleased.Desc()
+	ch <- m.heapObjects.Desc()
 }
 
 // Collect returns the current state of all metrics of the collector.
@@ -51,128 +145,6 @@ 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)
-}
-
-// memStatsCollector collects runtime.MemStats
-type memStatsCollector struct {
-	alloc        prometheus.Gauge
-	totalAlloc   prometheus.Gauge
-	sys          prometheus.Gauge
-	lookups      prometheus.Gauge
-	mallocs      prometheus.Gauge
-	frees        prometheus.Gauge
-	heapAlloc    prometheus.Gauge
-	heapSys      prometheus.Gauge
-	heapIdle     prometheus.Gauge
-	heapInuse    prometheus.Gauge
-	heapReleased prometheus.Gauge
-	heapObjects  prometheus.Gauge
-}
-
-// newMemStatsCollector creates a new runtime.MemStats collector
-func newMemStatsCollector() *memStatsCollector {
-	return &MemStatsCollector{
-		alloc: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "alloc_bytes",
-			Help:      "bytes allocated and still in use",
-		}),
-		totalAlloc: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "alloc_bytes_total",
-			Help:      "bytes allocated (even if freed)",
-		}),
-		sys: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "sys",
-			Help:      "bytes obtained from system",
-		}),
-		lookups: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "lookups",
-			Help:      "number of pointer lookups",
-		}),
-		mallocs: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "mallocs",
-			Help:      "number of mallocs",
-		}),
-		frees: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "frees",
-			Help:      "number of frees",
-		}),
-		heapAlloc: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "heap_alloc",
-			Help:      "bytes allocated and still in use",
-		}),
-		heapSys: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "heap_sys",
-			Help:      "bytes obtained from system",
-		}),
-		heapIdle: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "heap_idle",
-			Help:      "bytes in idle spans",
-		}),
-		heapInuse: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "heap_inuse",
-			Help:      "bytes in non-idle span",
-		}),
-		heapReleased: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "heap_released",
-			Help:      "bytes released to the OS",
-		}),
-		heapObjects: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: "go",
-			Subsystem: "memstats",
-			Name:      "heap_objects",
-			Help:      "total number of allocated objects",
-		}),
-	}
-}
-
-// Describe sends Desc objects for each memstat we intend to collect.
-func (m *MemStatsCollector) Describe(ch chan<- *prometheus.Desc) {
-	if m == nil {
-		m = NewMemStatsCollector()
-	}
-
-	ch <- m.alloc.Desc()
-	ch <- m.totalAlloc.Desc()
-	ch <- m.sys.Desc()
-	ch <- m.lookups.Desc()
-	ch <- m.mallocs.Desc()
-	ch <- m.frees.Desc()
-	ch <- m.heapAlloc.Desc()
-	ch <- m.heapSys.Desc()
-	ch <- m.heapIdle.Desc()
-	ch <- m.heapInuse.Desc()
-	ch <- m.heapReleased.Desc()
-	ch <- m.heapObjects.Desc()
-}
-
-// Collect does the trick by calling ReadMemStats once and then constructing
-// three different Metrics on the fly.
-func (m *MemStatsCollector) Collect(ch chan<- prometheus.Metric) {
-	if m == nil {
-		m = NewMemStatsCollector()
-	}
 
 	var ms runtime.MemStats
 	runtime.ReadMemStats(&ms)