vendor files

vendor/k8s.io/kubernetes/pkg/util/metrics/util.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package metrics
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/util/flowcontrol"
+
+	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	updatePeriod = 5 * time.Second
+)
+
+var (
+	metricsLock        sync.Mutex
+	rateLimiterMetrics = make(map[string]rateLimiterMetric)
+)
+
+type rateLimiterMetric struct {
+	metric prometheus.Gauge
+	stopCh chan struct{}
+}
+
+func registerRateLimiterMetric(ownerName string) error {
+	metricsLock.Lock()
+	defer metricsLock.Unlock()
+
+	if _, ok := rateLimiterMetrics[ownerName]; ok {
+		return fmt.Errorf("Rate Limiter Metric for %v already registered", ownerName)
+	}
+	metric := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name:      "rate_limiter_use",
+		Subsystem: ownerName,
+		Help:      fmt.Sprintf("A metric measuring the saturation of the rate limiter for %v", ownerName),
+	})
+	if err := prometheus.Register(metric); err != nil {
+		return fmt.Errorf("error registering rate limiter usage metric: %v", err)
+	}
+	stopCh := make(chan struct{})
+	rateLimiterMetrics[ownerName] = rateLimiterMetric{
+		metric: metric,
+		stopCh: stopCh,
+	}
+	return nil
+}
+
+// RegisterMetricAndTrackRateLimiterUsage registers a metric ownerName_rate_limiter_use in prometheus to track
+// how much used rateLimiter is and starts a goroutine that updates this metric every updatePeriod
+func RegisterMetricAndTrackRateLimiterUsage(ownerName string, rateLimiter flowcontrol.RateLimiter) error {
+	if err := registerRateLimiterMetric(ownerName); err != nil {
+		return err
+	}
+	go wait.Until(func() {
+		metricsLock.Lock()
+		defer metricsLock.Unlock()
+		rateLimiterMetrics[ownerName].metric.Set(rateLimiter.Saturation())
+	}, updatePeriod, rateLimiterMetrics[ownerName].stopCh)
+	return nil
+}
+
+// UnregisterMetricAndUntrackRateLimiterUsage unregisters a metric ownerName_rate_limiter_use from prometheus and
+// stops the goroutine that updates this metric
+func UnregisterMetricAndUntrackRateLimiterUsage(ownerName string) bool {
+	metricsLock.Lock()
+	defer metricsLock.Unlock()
+
+	rlm, ok := rateLimiterMetrics[ownerName]
+	if !ok {
+		glog.Warningf("Rate Limiter Metric for %v not registered", ownerName)
+		return false
+	}
+
+	close(rlm.stopCh)
+	prometheus.Unregister(rlm.metric)
+	delete(rateLimiterMetrics, ownerName)
+
+	return true
+}