Merge pull request #429 from brian-brazil/scrape-time

Have scrape time as a pseudovariable, not a prometheus variable.

retrieval/target.go

@@ -36,30 +36,19 @@ const (
 	InstanceLabel clientmodel.LabelName = "instance"
 	// ScrapeHealthMetricName is the metric name for the synthetic health
 	// variable.
-	ScrapeHealthMetricName clientmodel.LabelValue = "up"
+	scrapeHealthMetricName clientmodel.LabelValue = "up"
+	// ScrapeTimeMetricName is the metric name for the synthetic scrape duration
+	// variable.
+	scrapeDurationMetricName clientmodel.LabelValue = "scrape_duration_seconds"
 
 	// Constants for instrumentation.
 	namespace = "prometheus"
-	job       = "target_job"
-	instance  = "target_instance"
-	failure   = "failure"
-	outcome   = "outcome"
-	success   = "success"
 	interval  = "interval"
 )
 
 var (
 	localhostRepresentations = []string{"http://127.0.0.1", "http://localhost"}
 
-	targetOperationLatencies = prometheus.NewSummaryVec(
-		prometheus.SummaryOpts{
-			Namespace:  namespace,
-			Name:       "target_operation_latency_milliseconds",
-			Help:       "The latencies for target operations.",
-			Objectives: []float64{0.01, 0.05, 0.5, 0.90, 0.99},
-		},
-		[]string{job, instance, outcome},
-	)
 	targetIntervalLength = prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
 			Namespace:  namespace,
@@ -72,7 +61,6 @@ var (
 )
 
 func init() {
-	prometheus.MustRegister(targetOperationLatencies)
 	prometheus.MustRegister(targetIntervalLength)
 }
 
@@ -189,28 +177,37 @@ func NewTarget(url string, deadline time.Duration, baseLabels clientmodel.LabelS
 	return target
 }
 
-func (t *target) recordScrapeHealth(ingester extraction.Ingester, timestamp clientmodel.Timestamp, healthy bool) {
-	metric := clientmodel.Metric{}
+func (t *target) recordScrapeHealth(ingester extraction.Ingester, timestamp clientmodel.Timestamp, healthy bool, scrapeDuration time.Duration) {
+	healthMetric := clientmodel.Metric{}
+	durationMetric := clientmodel.Metric{}
 	for label, value := range t.baseLabels {
-		metric[label] = value
+		healthMetric[label] = value
+		durationMetric[label] = value
 	}
-	metric[clientmodel.MetricNameLabel] = clientmodel.LabelValue(ScrapeHealthMetricName)
-	metric[InstanceLabel] = clientmodel.LabelValue(t.URL())
+	healthMetric[clientmodel.MetricNameLabel] = clientmodel.LabelValue(scrapeHealthMetricName)
+	durationMetric[clientmodel.MetricNameLabel] = clientmodel.LabelValue(scrapeDurationMetricName)
+	healthMetric[InstanceLabel] = clientmodel.LabelValue(t.URL())
+	durationMetric[InstanceLabel] = clientmodel.LabelValue(t.URL())
 
 	healthValue := clientmodel.SampleValue(0)
 	if healthy {
 		healthValue = clientmodel.SampleValue(1)
 	}
 
-	sample := &clientmodel.Sample{
-		Metric:    metric,
+	healthSample := &clientmodel.Sample{
+		Metric:    healthMetric,
 		Timestamp: timestamp,
 		Value:     healthValue,
 	}
+	durationSample := &clientmodel.Sample{
+		Metric:    durationMetric,
+		Timestamp: timestamp,
+		Value:     clientmodel.SampleValue(float64(scrapeDuration) / float64(time.Second)),
+	}
 
 	ingester.Ingest(&extraction.Result{
 		Err:     nil,
-		Samples: clientmodel.Samples{sample},
+		Samples: clientmodel.Samples{healthSample, durationSample},
 	})
 }
 
@@ -292,23 +289,15 @@ const acceptHeader = `application/vnd.google.protobuf;proto=io.prometheus.client
 func (t *target) scrape(ingester extraction.Ingester) (err error) {
 	timestamp := clientmodel.Now()
 	defer func(start time.Time) {
-		ms := float64(time.Since(start)) / float64(time.Millisecond)
-		labels := prometheus.Labels{
-			job:      string(t.baseLabels[clientmodel.JobLabel]),
-			instance: t.URL(),
-			outcome:  success,
-		}
 		t.Lock() // Writing t.state and t.lastError requires the lock.
 		if err == nil {
 			t.state = Alive
-			labels[outcome] = failure
 		} else {
 			t.state = Unreachable
 		}
 		t.lastError = err
 		t.Unlock()
-		targetOperationLatencies.With(labels).Observe(ms)
-		t.recordScrapeHealth(ingester, timestamp, err == nil)
+		t.recordScrapeHealth(ingester, timestamp, err == nil, time.Since(start))
 	}(time.Now())
 
 	req, err := http.NewRequest("GET", t.URL(), nil)

retrieval/target_provider.go

@@ -33,17 +33,22 @@ import (
 const resolvConf = "/etc/resolv.conf"
 
 var (
-	dnsSDLookupsCount = prometheus.NewCounterVec(
+	dnsSDLookupsCount = prometheus.NewCounter(
 		prometheus.CounterOpts{
 			Namespace: namespace,
 			Name:      "dns_sd_lookups_total",
-			Help:      "The number of DNS-SD lookup successes/failures per pool.",
-		},
-		[]string{outcome},
-	)
+			Help:      "The number of DNS-SD lookups.",
+		})
+	dnsSDLookupFailuresCount = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: namespace,
+			Name:      "dns_sd_lookup_failures_total",
+			Help:      "The number of DNS-SD lookup failures.",
+		})
 )
 
 func init() {
+	prometheus.MustRegister(dnsSDLookupFailuresCount)
 	prometheus.MustRegister(dnsSDLookupsCount)
 }
 
@@ -77,11 +82,10 @@ func NewSdTargetProvider(job config.JobConfig) *sdTargetProvider {
 func (p *sdTargetProvider) Targets() ([]Target, error) {
 	var err error
 	defer func() {
-		message := success
+		dnsSDLookupsCount.Inc()
 		if err != nil {
-			message = failure
+			dnsSDLookupFailuresCount.Inc()
 		}
-		dnsSDLookupsCount.WithLabelValues(message).Inc()
 	}()
 
 	if time.Since(p.lastRefresh) < p.refreshInterval {

retrieval/target_test.go

@@ -39,7 +39,7 @@ func (i *collectResultIngester) Ingest(r *extraction.Result) error {
 func TestTargetScrapeUpdatesState(t *testing.T) {
 	testTarget := target{
 		state:      Unknown,
-		url:    "bad schema",
+		url:        "bad schema",
 		httpClient: utility.NewDeadlineClient(0),
 	}
 	testTarget.scrape(nopIngester{})
@@ -50,25 +50,25 @@ func TestTargetScrapeUpdatesState(t *testing.T) {
 
 func TestTargetRecordScrapeHealth(t *testing.T) {
 	testTarget := target{
-		url:    "http://example.url",
+		url:        "http://example.url",
 		baseLabels: clientmodel.LabelSet{clientmodel.JobLabel: "testjob"},
 		httpClient: utility.NewDeadlineClient(0),
 	}
 
 	now := clientmodel.Now()
 	ingester := &collectResultIngester{}
-	testTarget.recordScrapeHealth(ingester, now, true)
+	testTarget.recordScrapeHealth(ingester, now, true, 2 * time.Second)
 
 	result := ingester.result
 
-	if len(result.Samples) != 1 {
-		t.Fatalf("Expected one sample, got %d", len(result.Samples))
+	if len(result.Samples) != 2 {
+		t.Fatalf("Expected two samples, got %d", len(result.Samples))
 	}
 
 	actual := result.Samples[0]
 	expected := &clientmodel.Sample{
 		Metric: clientmodel.Metric{
-			clientmodel.MetricNameLabel: ScrapeHealthMetricName,
+			clientmodel.MetricNameLabel: scrapeHealthMetricName,
 			InstanceLabel:               "http://example.url",
 			clientmodel.JobLabel:        "testjob",
 		},
@@ -83,6 +83,25 @@ func TestTargetRecordScrapeHealth(t *testing.T) {
 	if !actual.Equal(expected) {
 		t.Fatalf("Expected and actual samples not equal. Expected: %v, actual: %v", expected, actual)
 	}
+
+	actual = result.Samples[1]
+	expected = &clientmodel.Sample{
+		Metric: clientmodel.Metric{
+			clientmodel.MetricNameLabel: scrapeDurationMetricName,
+			InstanceLabel:               "http://example.url",
+			clientmodel.JobLabel:        "testjob",
+		},
+		Timestamp: now,
+		Value:     2.0,
+	}
+
+	if result.Err != nil {
+		t.Fatalf("Got unexpected error: %v", result.Err)
+	}
+
+	if !actual.Equal(expected) {
+		t.Fatalf("Expected and actual samples not equal. Expected: %v, actual: %v", expected, actual)
+	}
 }
 
 func TestTargetScrapeTimeout(t *testing.T) {
@@ -147,7 +166,7 @@ func TestTargetScrape404(t *testing.T) {
 func TestTargetRunScraperScrapes(t *testing.T) {
 	testTarget := target{
 		state:           Unknown,
-		url:         "bad schema",
+		url:             "bad schema",
 		httpClient:      utility.NewDeadlineClient(0),
 		scraperStopping: make(chan struct{}),
 		scraperStopped:  make(chan struct{}),

retrieval/targetmanager.go

@@ -15,6 +15,7 @@ package retrieval
 
 import (
 	"sync"
+
 	"github.com/golang/glog"
 	"github.com/prometheus/client_golang/extraction"
 

retrieval/targetpool_test.go

@@ -27,7 +27,7 @@ func testTargetPool(t testing.TB) {
 	}
 
 	type input struct {
-		url      string
+		url          string
 		scheduledFor time.Time
 	}
 
@@ -84,7 +84,7 @@ func testTargetPool(t testing.TB) {
 
 		for _, input := range scenario.inputs {
 			target := target{
-				url:       input.url,
+				url:           input.url,
 				newBaseLabels: make(chan clientmodel.LabelSet, 1),
 				httpClient:    &http.Client{},
 			}
@@ -114,7 +114,7 @@ func TestTargetPool(t *testing.T) {
 func TestTargetPoolReplaceTargets(t *testing.T) {
 	pool := NewTargetPool(nil, nil, nopIngester{}, time.Duration(1))
 	oldTarget1 := &target{
-		url:         "example1",
+		url:             "example1",
 		state:           Unreachable,
 		scraperStopping: make(chan struct{}),
 		scraperStopped:  make(chan struct{}),
@@ -122,7 +122,7 @@ func TestTargetPoolReplaceTargets(t *testing.T) {
 		httpClient:      &http.Client{},
 	}
 	oldTarget2 := &target{
-		url:         "example2",
+		url:             "example2",
 		state:           Unreachable,
 		scraperStopping: make(chan struct{}),
 		scraperStopped:  make(chan struct{}),
@@ -130,7 +130,7 @@ func TestTargetPoolReplaceTargets(t *testing.T) {
 		httpClient:      &http.Client{},
 	}
 	newTarget1 := &target{
-		url:         "example1",
+		url:             "example1",
 		state:           Alive,
 		scraperStopping: make(chan struct{}),
 		scraperStopped:  make(chan struct{}),
@@ -138,7 +138,7 @@ func TestTargetPoolReplaceTargets(t *testing.T) {
 		httpClient:      &http.Client{},
 	}
 	newTarget2 := &target{
-		url:         "example3",
+		url:             "example3",
 		state:           Alive,
 		scraperStopping: make(chan struct{}),
 		scraperStopped:  make(chan struct{}),

storage/local/persistence.go

@@ -869,7 +869,7 @@ func (p *persistence) checkpointSeriesMapAndHeads(fingerprintToSeries *seriesMap
 	iter := fingerprintToSeries.iter()
 	defer func() {
 		// Consume the iterator in any case to not leak goroutines.
-		for _ = range iter {
+		for range iter {
 		}
 	}()
 

storage/local/storage.go

@@ -567,7 +567,7 @@ func (s *memorySeriesStorage) cycleThroughMemoryFingerprints() chan clientmodel.
 
 		defer func() {
 			if fpIter != nil {
-				for _ = range fpIter {
+				for range fpIter {
 					// Consume the iterator.
 				}
 			}
@@ -661,9 +661,9 @@ loop:
 		}
 	}
 	// Wait until both channels are closed.
-	for _ = range memoryFingerprints {
+	for range memoryFingerprints {
 	}
-	for _ = range archivedFingerprints {
+	for range archivedFingerprints {
 	}
 }