Enable concurrent workers for tagging controller

pkg/controllers/options/tagging_controller.go

@@ -21,10 +21,11 @@ import (
 // TaggingControllerOptions contains the inputs that can
 // be used in the tagging controller
 type TaggingControllerOptions struct {
-	Tags       map[string]string
-	Resources  []string
-	RateLimit  float64
-	BurstLimit int
+	Tags        map[string]string
+	Resources   []string
+	RateLimit   float64
+	BurstLimit  int
+	WorkerCount int
 }
 
 // AddFlags add the additional flags for the controller
@@ -35,6 +36,8 @@ func (o *TaggingControllerOptions) AddFlags(fs *pflag.FlagSet) {
 		"Steady-state rate limit (per sec) at which the controller processes items in its queue. A value of zero (default) disables rate limiting.")
 	fs.IntVar(&o.BurstLimit, "tagging-controller-burst-limit", o.BurstLimit,
 		"Burst limit at which the controller processes items in its queue. A value of zero (default) disables rate limiting.")
+	fs.IntVar(&o.WorkerCount, "tagging-controller-concurrent-node-syncs", 1,
+		"The number of workers concurrently synchronizing nodes")
 }
 
 // Validate checks for errors from user input
@@ -55,6 +58,10 @@ func (o *TaggingControllerOptions) Validate() error {
 		return fmt.Errorf("--tagging-controller-burst-limit should not be less than zero")
 	}
 
+	if o.WorkerCount <= 0 {
+		return fmt.Errorf("--tagging-controller-concurrent-node-syncs must be a positive number")
+	}
+
 	for _, r := range o.Resources {
 		for _, resource := range SupportedResources {
 			if r != resource {

pkg/controllers/tagging/tagging_controller.go

@@ -101,6 +101,7 @@ type Controller struct {
 	resources []string
 
 	rateLimitEnabled bool
+	workerCount      int
 }
 
 // NewTaggingController creates a NewTaggingController object
@@ -112,7 +113,8 @@ func NewTaggingController(
 	tags map[string]string,
 	resources []string,
 	rateLimit float64,
-	burstLimit int) (*Controller, error) {
+	burstLimit int,
+	workerCount int) (*Controller, error) {
 
 	awsCloud, ok := cloud.(*awsv1.Cloud)
 	if !ok {
@@ -149,6 +151,7 @@ func NewTaggingController(
 		nodesSynced:       nodeInformer.Informer().HasSynced,
 		nodeMonitorPeriod: nodeMonitorPeriod,
 		rateLimitEnabled:  rateLimitEnabled,
+		workerCount:       workerCount,
 	}
 
 	// Use shared informer to listen to add/update/delete of nodes. Note that any nodes
@@ -194,7 +197,9 @@ func (tc *Controller) Run(stopCh <-chan struct{}) {
 	}
 
 	klog.Infof("Starting the tagging controller")
-	go wait.Until(tc.work, tc.nodeMonitorPeriod, stopCh)
+	for i := 0; i < tc.workerCount; i++ {
+		go wait.Until(tc.work, tc.nodeMonitorPeriod, stopCh)
+	}
 
 	<-stopCh
 }

pkg/controllers/tagging/tagging_controller_test.go

@@ -301,7 +301,7 @@ func TestMultipleEnqueues(t *testing.T) {
 		t.Errorf("unexpected error: %v", err)
 	}
 
-	tc, err := NewTaggingController(nodeInformer, clientset, fakeAws, time.Second, nil, []string{}, 0, 0)
+	tc, err := NewTaggingController(nodeInformer, clientset, fakeAws, time.Second, nil, []string{}, 0, 0, 10)
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}

pkg/controllers/tagging/tagging_controller_wrapper.go

@@ -48,7 +48,8 @@ func (tc *ControllerWrapper) startTaggingController(ctx context.Context, initCon
 		tc.Options.Tags,
 		tc.Options.Resources,
 		tc.Options.RateLimit,
-		tc.Options.BurstLimit)
+		tc.Options.BurstLimit,
+		tc.Options.WorkerCount)
 
 	if err != nil {
 		klog.Warningf("failed to start tagging controller: %s", err)