Add benchmark for warnIfTargetsRelabelledToSameLabels

Signed-off-by: darshanime <deathbullet@gmail.com>

scrape/manager.go

@@ -169,6 +169,7 @@ func (m *Manager) reloader() {
 func (m *Manager) reload() {
 	m.mtxScrape.Lock()
 	var wg sync.WaitGroup
+
 	for setName, groups := range m.targetSets {
 		if _, ok := m.scrapePools[setName]; !ok {
 			scrapeConfig, ok := m.scrapeConfigs[setName]
@@ -214,9 +215,10 @@ func (m *Manager) warnIfTargetsRelabelledToSameLabels() {
 	activeTargets := make(map[uint64]*Target)
 	for _, scrapePool := range m.scrapePools {
 		for _, target := range scrapePool.activeTargets {
-			t, ok := activeTargets[target.labels.Hash()]
+			lHash := target.labels.Hash()
+			t, ok := activeTargets[lHash]
 			if !ok {
-				activeTargets[target.labels.Hash()] = target
+				activeTargets[lHash] = target
 				continue
 			}
 			level.Warn(m.logger).Log(

scrape/manager_test.go

@@ -622,6 +622,31 @@ func TestManagerTargetsUpdates(t *testing.T) {
 	}
 }
 
+func BenchmarkManagerReload(b *testing.B) {
+	opts := Options{}
+	testRegistry := prometheus.NewRegistry()
+	m, err := NewManager(&opts, nil, nil, testRegistry)
+	require.NoError(b, err)
+
+	m.scrapePools = map[string]*scrapePool{}
+	sp := &scrapePool{
+		activeTargets: map[uint64]*Target{},
+	}
+
+	for i := 0; i < b.N; i++ {
+		sp.activeTargets[uint64(i)] = &Target{
+			discoveredLabels: labels.FromStrings("__address__", fmt.Sprintf("foo-%d", i)),
+			labels:           labels.FromStrings("label_key", fmt.Sprintf("foo-%d", i)),
+		}
+	}
+
+	m.scrapePools["default"] = sp
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		m.reload()
+	}
+}
+
 func TestManagerDuplicateAfterRelabellingWarning(t *testing.T) {
 	var output []interface{}
 	logger := log.Logger(log.LoggerFunc(func(keyvals ...interface{}) error {