Added memory sytem metrics

metric.go

@@ -36,6 +36,12 @@ const (
 	MetricGoRoutines = "GoRoutines"
 	// MetricGoVersion holds the go version as Major*10000+Minor*100+Patch
 	MetricGoVersion = "GoVersion"
+	// MetricMemoryAllocated holds the currently active memory in bytes
+	MetricMemoryAllocated = "GoMemoryAllocated"
+	// MetricMemoryNumObjects holds the total number of allocated heap objects
+	MetricMemoryNumObjects = "GoMemoryNumObjects"
+	// MetricMemoryGCEnabled holds 1 or 0 depending on the state of garbage collection
+	MetricMemoryGCEnabled = "GoMemoryGCEnabled"
 )
 
 // ProcessStartTime stores the time this process has started.
@@ -47,6 +53,9 @@ func init() {
 	Metric.New(MetricProcessStart)
 	Metric.New(MetricGoRoutines)
 	Metric.New(MetricGoVersion)
+	Metric.New(MetricMemoryAllocated)
+	Metric.New(MetricMemoryNumObjects)
+	Metric.New(MetricMemoryGCEnabled)
 	Metric.Set(MetricProcessStart, ProcessStartTime.Unix())
 
 	version := runtime.Version()
@@ -101,6 +110,17 @@ func (met *metrics) SetF(name string, value float64) {
 	atomic.StoreInt64(met.store[name], int64(rounded))
 }
 
+// SetB is Set for boolean values (conversion to 0/1)
+func (met *metrics) SetB(name string, value bool) {
+	ivalue := 0
+	if value {
+		ivalue = 1
+	}
+	met.mutex.RLock()
+	defer met.mutex.RUnlock()
+	atomic.StoreInt64(met.store[name], int64(ivalue))
+}
+
 // Inc adds 1 to a given metric. This operation is atomic.
 func (met *metrics) Inc(name string) {
 	met.mutex.RLock()
@@ -175,7 +195,14 @@ func (met *metrics) Get(name string) (int64, error) {
 func (met *metrics) UpdateSystemMetrics() {
 	met.mutex.RLock()
 	defer met.mutex.RUnlock()
+
+	stats := new(runtime.MemStats)
+	runtime.ReadMemStats(stats)
+
 	met.SetI(MetricGoRoutines, runtime.NumGoroutine())
+	met.Set(MetricMemoryAllocated, int64(stats.Alloc))
+	met.SetB(MetricMemoryGCEnabled, stats.EnableGC)
+	met.Set(MetricMemoryNumObjects, int64(stats.HeapObjects))
 }
 
 // Dump creates a JSON string from all stored metrics.

metric_test.go

@@ -54,6 +54,17 @@ func TestMetricsSet(t *testing.T) {
 	count, err = mockMetric.Get("MockMetric")
 	expect.Nil(err)
 	expect.Equal(int64(4), count)
+
+	// test for setting a particular boolean value
+	mockMetric.SetB("MockMetric", true)
+	count, err = mockMetric.Get("MockMetric")
+	expect.Nil(err)
+	expect.Equal(int64(1), count)
+
+	mockMetric.SetB("MockMetric", false)
+	count, err = mockMetric.Get("MockMetric")
+	expect.Nil(err)
+	expect.Equal(int64(0), count)
 }
 
 func TestMetricsAddSub(t *testing.T) {