Merge pull request #30296 from deads2k/wq-metrics

Automatic merge from submit-queue

add metrics for workqueues

Adds prometheus metrics to work queues and enables them for the resourcequota controller.  It would be easy to add this to all other workqueue based controllers and gather basic responsiveness metrics.

@kubernetes/rh-cluster-infra helps debug quota controller responsiveness problems.

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pkg/controller/resourcequota/resource_quota_controller.go

@@ -79,8 +79,8 @@ func NewResourceQuotaController(options *ResourceQuotaControllerOptions) *Resour
 	// build the resource quota controller
 	rq := &ResourceQuotaController{
 		kubeClient:               options.KubeClient,
-		queue:                    workqueue.NewRateLimitingQueue(workqueue.DefaultControllerRateLimiter()),
-		missingUsageQueue:        workqueue.NewRateLimitingQueue(workqueue.DefaultControllerRateLimiter()),
+		queue:                    workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "controller_resourcequota_primary"),
+		missingUsageQueue:        workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "controller_resourcequota_priority"),
 		resyncPeriod:             options.ResyncPeriod,
 		registry:                 options.Registry,
 		replenishmentControllers: []framework.ControllerInterface{},

pkg/util/workqueue/delaying_queue.go

@@ -34,17 +34,22 @@ type DelayingInterface interface {
 
 // NewDelayingQueue constructs a new workqueue with delayed queuing ability
 func NewDelayingQueue() DelayingInterface {
-	return newDelayingQueue(clock.RealClock{})
+	return newDelayingQueue(clock.RealClock{}, "")
 }
 
-func newDelayingQueue(clock clock.Clock) DelayingInterface {
+func NewNamedDelayingQueue(name string) DelayingInterface {
+	return newDelayingQueue(clock.RealClock{}, name)
+}
+
+func newDelayingQueue(clock clock.Clock, name string) DelayingInterface {
 	ret := &delayingType{
-		Interface:          New(),
+		Interface:          NewNamed(name),
 		clock:              clock,
 		heartbeat:          clock.Tick(maxWait),
 		stopCh:             make(chan struct{}),
 		waitingTimeByEntry: map[t]time.Time{},
 		waitingForAddCh:    make(chan waitFor, 1000),
+		metrics:            newRetryMetrics(name),
 	}
 
 	go ret.waitingLoop()
@@ -71,6 +76,9 @@ type delayingType struct {
 	waitingTimeByEntry map[t]time.Time
 	// waitingForAddCh is a buffered channel that feeds waitingForAdd
 	waitingForAddCh chan waitFor
+
+	// metrics counts the number of retries
+	metrics retryMetrics
 }
 
 // waitFor holds the data to add and the time it should be added
@@ -92,6 +100,8 @@ func (q *delayingType) AddAfter(item interface{}, duration time.Duration) {
 		return
 	}
 
+	q.metrics.retry()
+
 	// immediately add things with no delay
 	if duration <= 0 {
 		q.Add(item)

pkg/util/workqueue/delaying_queue_test.go

@@ -28,7 +28,7 @@ import (
 
 func TestSimpleQueue(t *testing.T) {
 	fakeClock := clock.NewFakeClock(time.Now())
-	q := newDelayingQueue(fakeClock)
+	q := newDelayingQueue(fakeClock, "")
 
 	first := "foo"
 
@@ -70,7 +70,7 @@ func TestSimpleQueue(t *testing.T) {
 
 func TestDeduping(t *testing.T) {
 	fakeClock := clock.NewFakeClock(time.Now())
-	q := newDelayingQueue(fakeClock)
+	q := newDelayingQueue(fakeClock, "")
 
 	first := "foo"
 
@@ -129,7 +129,7 @@ func TestDeduping(t *testing.T) {
 
 func TestAddTwoFireEarly(t *testing.T) {
 	fakeClock := clock.NewFakeClock(time.Now())
-	q := newDelayingQueue(fakeClock)
+	q := newDelayingQueue(fakeClock, "")
 
 	first := "foo"
 	second := "bar"
@@ -179,7 +179,7 @@ func TestAddTwoFireEarly(t *testing.T) {
 
 func TestCopyShifting(t *testing.T) {
 	fakeClock := clock.NewFakeClock(time.Now())
-	q := newDelayingQueue(fakeClock)
+	q := newDelayingQueue(fakeClock, "")
 
 	first := "foo"
 	second := "bar"

pkg/util/workqueue/metrics.go

@@ -0,0 +1,153 @@
+/*
+Copyright 2016 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 workqueue
+
+import (
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type queueMetrics interface {
+	add(item t)
+	get(item t)
+	done(item t)
+}
+
+type defaultQueueMetrics struct {
+	depth                prometheus.Gauge
+	adds                 prometheus.Counter
+	latency              prometheus.Summary
+	workDuration         prometheus.Summary
+	addTimes             map[t]time.Time
+	processingStartTimes map[t]time.Time
+}
+
+func newQueueMetrics(name string) queueMetrics {
+	var ret *defaultQueueMetrics
+	if len(name) == 0 {
+		return ret
+	}
+
+	ret = &defaultQueueMetrics{
+		depth: prometheus.NewGauge(prometheus.GaugeOpts{
+			Subsystem: name,
+			Name:      "depth",
+			Help:      "Current depth of workqueue: " + name,
+		}),
+		adds: prometheus.NewCounter(prometheus.CounterOpts{
+			Subsystem: name,
+			Name:      "adds",
+			Help:      "Total number of adds handled by workqueue: " + name,
+		}),
+		latency: prometheus.NewSummary(prometheus.SummaryOpts{
+			Subsystem: name,
+			Name:      "queue_latency",
+			Help:      "How long an item stays in workqueue" + name + " before being requested.",
+		}),
+		workDuration: prometheus.NewSummary(prometheus.SummaryOpts{
+			Subsystem: name,
+			Name:      "work_duration",
+			Help:      "How long processing an item from workqueue" + name + " takes.",
+		}),
+		addTimes:             map[t]time.Time{},
+		processingStartTimes: map[t]time.Time{},
+	}
+
+	prometheus.Register(ret.depth)
+	prometheus.Register(ret.adds)
+	prometheus.Register(ret.latency)
+	prometheus.Register(ret.workDuration)
+
+	return ret
+}
+
+func (m *defaultQueueMetrics) add(item t) {
+	if m == nil {
+		return
+	}
+
+	m.adds.Inc()
+	m.depth.Inc()
+	if _, exists := m.addTimes[item]; !exists {
+		m.addTimes[item] = time.Now()
+	}
+}
+
+func (m *defaultQueueMetrics) get(item t) {
+	if m == nil {
+		return
+	}
+
+	m.depth.Dec()
+	m.processingStartTimes[item] = time.Now()
+	if startTime, exists := m.addTimes[item]; exists {
+		m.latency.Observe(sinceInMicroseconds(startTime))
+		delete(m.addTimes, item)
+	}
+}
+
+func (m *defaultQueueMetrics) done(item t) {
+	if m == nil {
+		return
+	}
+
+	if startTime, exists := m.processingStartTimes[item]; exists {
+		m.workDuration.Observe(sinceInMicroseconds(startTime))
+		delete(m.processingStartTimes, item)
+	}
+}
+
+// Gets the time since the specified start in microseconds.
+func sinceInMicroseconds(start time.Time) float64 {
+	return float64(time.Since(start).Nanoseconds() / time.Microsecond.Nanoseconds())
+}
+
+type retryMetrics interface {
+	retry()
+}
+
+type defaultRetryMetrics struct {
+	retries prometheus.Counter
+}
+
+func newRetryMetrics(name string) retryMetrics {
+	var ret *defaultRetryMetrics
+	if len(name) == 0 {
+		return ret
+	}
+
+	ret = &defaultRetryMetrics{
+		retries: prometheus.NewCounter(prometheus.CounterOpts{
+			Subsystem: name,
+			Name:      "retries",
+			Help:      "Total number of retries handled by workqueue: " + name,
+		}),
+	}
+
+	prometheus.Register(ret.retries)
+
+	return ret
+}
+
+func (m *defaultRetryMetrics) retry() {
+	if m == nil {
+		return
+	}
+
+	m.retries.Inc()
+}

pkg/util/workqueue/queue.go

@@ -31,10 +31,15 @@ type Interface interface {
 
 // New constructs a new workqueue (see the package comment).
 func New() *Type {
+	return NewNamed("")
+}
+
+func NewNamed(name string) *Type {
 	return &Type{
 		dirty:      set{},
 		processing: set{},
 		cond:       sync.NewCond(&sync.Mutex{}),
+		metrics:    newQueueMetrics(name),
 	}
 }
 
@@ -57,6 +62,8 @@ type Type struct {
 	cond *sync.Cond
 
 	shuttingDown bool
+
+	metrics queueMetrics
 }
 
 type empty struct{}
@@ -86,10 +93,14 @@ func (q *Type) Add(item interface{}) {
 	if q.dirty.has(item) {
 		return
 	}
+
+	q.metrics.add(item)
+
 	q.dirty.insert(item)
 	if q.processing.has(item) {
 		return
 	}
+
 	q.queue = append(q.queue, item)
 	q.cond.Signal()
 }
@@ -116,9 +127,14 @@ func (q *Type) Get() (item interface{}, shutdown bool) {
 		// We must be shutting down.
 		return nil, true
 	}
+
 	item, q.queue = q.queue[0], q.queue[1:]
+
+	q.metrics.get(item)
+
 	q.processing.insert(item)
 	q.dirty.delete(item)
+
 	return item, false
 }
 
@@ -128,6 +144,9 @@ func (q *Type) Get() (item interface{}, shutdown bool) {
 func (q *Type) Done(item interface{}) {
 	q.cond.L.Lock()
 	defer q.cond.L.Unlock()
+
+	q.metrics.done(item)
+
 	q.processing.delete(item)
 	if q.dirty.has(item) {
 		q.queue = append(q.queue, item)

pkg/util/workqueue/rate_limitting_queue.go

@@ -40,6 +40,13 @@ func NewRateLimitingQueue(rateLimiter RateLimiter) RateLimitingInterface {
 	}
 }
 
+func NewNamedRateLimitingQueue(rateLimiter RateLimiter, name string) RateLimitingInterface {
+	return &rateLimitingType{
+		DelayingInterface: NewNamedDelayingQueue(name),
+		rateLimiter:       rateLimiter,
+	}
+}
+
 // rateLimitingType wraps an Interface and provides rateLimited re-enquing
 type rateLimitingType struct {
 	DelayingInterface

pkg/util/workqueue/rate_limitting_queue_test.go

@@ -33,6 +33,7 @@ func TestRateLimitingQueue(t *testing.T) {
 		heartbeat:       fakeClock.Tick(maxWait),
 		stopCh:          make(chan struct{}),
 		waitingForAddCh: make(chan waitFor, 1000),
+		metrics:         newRetryMetrics(""),
 	}
 	queue.DelayingInterface = delayingQueue