ceph-csi/vendor/k8s.io/kubernetes/pkg/util/metrics/util.go
Serguei Bezverkhi e9033989a0 vendor updates
2018-03-07 11:43:06 -05:00

101 lines
2.9 KiB
Go

/*
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/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
}
// TODO: determine how to track rate limiter saturation
// See discussion at https://go-review.googlesource.com/c/time/+/29958#message-4caffc11669cadd90e2da4c05122cfec50ea6a22
// go wait.Until(func() {
// metricsLock.Lock()
// defer metricsLock.Unlock()
// rateLimiterMetrics[ownerName].metric.Set()
// }, 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
}