func (s *summary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.objectives))
s.bufMtx.Lock()
s.mtx.Lock()
if len(s.hotBuf) != 0 {
s.swapBufs(time.Now())
}
s.bufMtx.Unlock()
s.flushColdBuf()
sum.SampleCount = proto.Uint64(s.cnt)
sum.SampleSum = proto.Float64(s.sum)
for _, rank := range s.sortedObjectives {
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(s.headStream.Query(rank)),
})
}
s.mtx.Unlock()
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
func testMetric(t *testing.T, v expvar.Var, load func(), desc string, vals ...string) {
coll := NewCollector(prometheus.Opts{
Name: "test_name",
Help: "test_help",
}, v)
if load != nil {
load()
}
ch := make(chan prometheus.Metric, 1)
go func() {
coll.Collect(ch)
close(ch)
}()
for _, val := range vals {
met, ok := <-ch
if !ok {
t.Error("coll.Collect(ch): too few metrics returned")
}
if got := met.Desc().String(); got != desc {
t.Errorf("met.Desc().String(): %q, want %q", got, desc)
}
m := pb.Metric{}
if err := met.Write(&m); err != nil {
t.Fatalf("met.Write(): err=%s, want nil", err)
}
if got := m.String(); got != val {
t.Errorf("met.Write(&m); m.String(): %q, want %q", got, val)
}
}
_, ok := <-ch
if ok {
t.Error("coll.Collect(ch): too many metrics returned")
}
}
func makeQuantiles(m *dto.Metric) map[string]string {
result := map[string]string{}
for _, q := range m.GetSummary().Quantile {
result[fmt.Sprint(q.GetQuantile())] = fmt.Sprint(q.GetValue())
}
return result
}
func makeBuckets(m *dto.Metric) map[string]string {
result := map[string]string{}
for _, b := range m.GetHistogram().Bucket {
result[fmt.Sprint(b.GetUpperBound())] = fmt.Sprint(b.GetCumulativeCount())
}
return result
}
// Get Buckets from histogram metric
func makeBuckets(m *dto.Metric) map[string]interface{} {
fields := make(map[string]interface{})
for _, b := range m.GetHistogram().Bucket {
fields[fmt.Sprint(b.GetUpperBound())] = float64(b.GetCumulativeCount())
}
return fields
}
func (r *registry) giveMetric(m *dto.Metric) {
m.Reset()
select {
case r.metricPool <- m:
default:
}
}
// Get Quantiles from summary metric
func makeQuantiles(m *dto.Metric) map[string]interface{} {
fields := make(map[string]interface{})
for _, q := range m.GetSummary().Quantile {
if !math.IsNaN(q.GetValue()) {
fields[fmt.Sprint(q.GetQuantile())] = float64(q.GetValue())
}
}
return fields
}
func populateMetric(
t ValueType,
v float64,
labelPairs []*dto.LabelPair,
m *dto.Metric,
) {
m.Label = labelPairs
switch t {
case CounterValue:
m.Counter = &dto.Counter{Value: proto.Float64(v)}
case GaugeValue:
m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
case UntypedValue:
m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
default:
panic(fmt.Errorf("encountered unknown type %v", t))
}
}
func (h *histogram) Write(out *dto.Metric) error {
his := &dto.Histogram{}
buckets := make([]*dto.Bucket, len(h.upperBounds))
his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&h.sumBits)))
his.SampleCount = proto.Uint64(atomic.LoadUint64(&h.count))
var count uint64
for i, upperBound := range h.upperBounds {
count += atomic.LoadUint64(&h.counts[i])
buckets[i] = &dto.Bucket{
CumulativeCount: proto.Uint64(count),
UpperBound: proto.Float64(upperBound),
}
}
his.Bucket = buckets
out.Histogram = his
out.Label = h.labelPairs
return nil
}
func (t *UptimeSuite) TestUptimeReporting(c *gc.C) {
now := time.Now()
u, err := monitoring.NewUptimeCollector("test", "test", "test", time.Now)
c.Assert(err, jc.ErrorIsNil)
ch := make(chan prometheus.Metric, 1000)
u.Collect(ch)
var m prometheus.Metric
select {
case m = <-ch:
default:
c.Error("metric not provided by collector")
}
var raw prometheusinternal.Metric
err = m.Write(&raw)
c.Assert(err, jc.ErrorIsNil)
cnt := raw.GetCounter()
val := cnt.GetValue()
c.Assert(val, gc.Equals, float64(now.Unix()))
}
func (s *summary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.objectives))
s.bufMtx.Lock()
s.mtx.Lock()
// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
s.swapBufs(time.Now())
s.bufMtx.Unlock()
s.flushColdBuf()
sum.SampleCount = proto.Uint64(s.cnt)
sum.SampleSum = proto.Float64(s.sum)
for _, rank := range s.sortedObjectives {
var q float64
if s.headStream.Count() == 0 {
q = math.NaN()
} else {
q = s.headStream.Query(rank)
}
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
s.mtx.Unlock()
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
func (s *constSummary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.quantiles))
sum.SampleCount = proto.Uint64(s.count)
sum.SampleSum = proto.Float64(s.sum)
for rank, q := range s.quantiles {
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
func (h *constHistogram) Write(out *dto.Metric) error {
his := &dto.Histogram{}
buckets := make([]*dto.Bucket, 0, len(h.buckets))
his.SampleCount = proto.Uint64(h.count)
his.SampleSum = proto.Float64(h.sum)
for upperBound, count := range h.buckets {
buckets = append(buckets, &dto.Bucket{
CumulativeCount: proto.Uint64(count),
UpperBound: proto.Float64(upperBound),
})
}
if len(buckets) > 0 {
sort.Sort(buckSort(buckets))
}
his.Bucket = buckets
out.Histogram = his
out.Label = h.labelPairs
return nil
}
func getValue(m *dto.Metric) float64 {
if m.Gauge != nil {
return m.GetGauge().GetValue()
}
if m.Counter != nil {
return m.GetCounter().GetValue()
}
if m.Untyped != nil {
return m.GetUntyped().GetValue()
}
return 0.
}
func (cm *CallbackMetric) Write(m *dto.Metric) {
m.Untyped = &dto.Untyped{Value: proto.Float64(cm.callback())}
}
func ExampleExpvarCollector() {
expvarCollector := prometheus.NewExpvarCollector(map[string]*prometheus.Desc{
"memstats": prometheus.NewDesc(
"expvar_memstats",
"All numeric memstats as one metric family. Not a good role-model, actually... ;-)",
[]string{"type"}, nil,
),
"lone-int": prometheus.NewDesc(
"expvar_lone_int",
"Just an expvar int as an example.",
nil, nil,
),
"http-request-map": prometheus.NewDesc(
"expvar_http_request_total",
"How many http requests processed, partitioned by status code and http method.",
[]string{"code", "method"}, nil,
),
})
prometheus.MustRegister(expvarCollector)
// The Prometheus part is done here. But to show that this example is
// doing anything, we have to manually export something via expvar. In
// real-life use-cases, some library would already have exported via
// expvar what we want to re-export as Prometheus metrics.
expvar.NewInt("lone-int").Set(42)
expvarMap := expvar.NewMap("http-request-map")
var (
expvarMap1, expvarMap2 expvar.Map
expvarInt11, expvarInt12, expvarInt21, expvarInt22 expvar.Int
)
expvarMap1.Init()
expvarMap2.Init()
expvarInt11.Set(3)
expvarInt12.Set(13)
expvarInt21.Set(11)
expvarInt22.Set(212)
expvarMap1.Set("POST", &expvarInt11)
expvarMap1.Set("GET", &expvarInt12)
expvarMap2.Set("POST", &expvarInt21)
expvarMap2.Set("GET", &expvarInt22)
expvarMap.Set("404", &expvarMap1)
expvarMap.Set("200", &expvarMap2)
// Results in the following expvar map:
// "http-request-count": {"200": {"POST": 11, "GET": 212}, "404": {"POST": 3, "GET": 13}}
// Let's see what the scrape would yield, but exclude the memstats metrics.
metricStrings := []string{}
metric := dto.Metric{}
metricChan := make(chan prometheus.Metric)
go func() {
expvarCollector.Collect(metricChan)
close(metricChan)
}()
for m := range metricChan {
if strings.Index(m.Desc().String(), "expvar_memstats") == -1 {
metric.Reset()
m.Write(&metric)
metricStrings = append(metricStrings, metric.String())
}
}
sort.Strings(metricStrings)
for _, s := range metricStrings {
fmt.Println(strings.TrimRight(s, " "))
}
// Output:
// label:<name:"code" value:"200" > label:<name:"method" value:"GET" > untyped:<value:212 >
// label:<name:"code" value:"200" > label:<name:"method" value:"POST" > untyped:<value:11 >
// label:<name:"code" value:"404" > label:<name:"method" value:"GET" > untyped:<value:13 >
// label:<name:"code" value:"404" > label:<name:"method" value:"POST" > untyped:<value:3 >
// untyped:<value:42 >
}
func (cm *CallbackMetric) Write(m *dto.Metric) error {
m.Untyped = &dto.Untyped{Value: proto.Float64(cm.callback())}
return nil
}
// Get name and value from metric
func getNameAndValue(m *dto.Metric) map[string]interface{} {
fields := make(map[string]interface{})
if m.Gauge != nil {
if !math.IsNaN(m.GetGauge().GetValue()) {
fields["gauge"] = float64(m.GetGauge().GetValue())
}
} else if m.Counter != nil {
if !math.IsNaN(m.GetGauge().GetValue()) {
fields["counter"] = float64(m.GetCounter().GetValue())
}
} else if m.Untyped != nil {
if !math.IsNaN(m.GetGauge().GetValue()) {
fields["value"] = float64(m.GetUntyped().GetValue())
}
}
return fields
}
func (s *collectionSizeSuite) TestCollectionSizeReporting(c *gc.C) {
collection := s.Session.DB("test").C("test_collection")
u := monitoring.NewCollectionSizeCollector("test", "test", "test", collection)
defer u.Close()
err := collection.Insert(bson.M{"test": true})
c.Assert(err, jc.ErrorIsNil)
ch := make(chan prometheus.Metric, 2)
u.Collect(ch)
var m prometheus.Metric
// read the size
select {
case m = <-ch:
default:
c.Error("metric not provided by collector")
}
var raw prometheusinternal.Metric
err = m.Write(&raw)
c.Assert(err, jc.ErrorIsNil)
cnt := raw.GetGauge()
valueOne := cnt.GetValue()
// read the count
select {
case m = <-ch:
default:
c.Error("metric not provided by collector")
}
err = m.Write(&raw)
c.Assert(err, jc.ErrorIsNil)
cnt = raw.GetGauge()
val := cnt.GetValue()
c.Assert(val, gc.Equals, float64(1.0))
err = collection.Insert(bson.M{"test": true})
c.Assert(err, jc.ErrorIsNil)
u.Collect(ch)
// read the size
select {
case m = <-ch:
default:
c.Error("metric not provided by collector")
}
err = m.Write(&raw)
c.Assert(err, jc.ErrorIsNil)
cnt = raw.GetGauge()
valueTwo := cnt.GetValue()
c.Assert(2*valueOne, gc.Equals, valueTwo)
// read the count
select {
case m = <-ch:
default:
c.Error("metric not provided by collector")
}
err = m.Write(&raw)
c.Assert(err, jc.ErrorIsNil)
cnt = raw.GetGauge()
val = cnt.GetValue()
c.Assert(val, gc.Equals, float64(2.0))
}