feat(controller): Add --qps and --burst flags to controller (#3180)

cmd/workflow-controller/main.go

@@ -40,6 +40,8 @@ func NewRootCommand() *cobra.Command {
 		glogLevel                int    // --gloglevel
 		workflowWorkers          int    // --workflow-workers
 		podWorkers               int    // --pod-workers
+		burst                    int
+		qps                      float32
 		namespaced               bool   // --namespaced
 		managedNamespace         string // --managed-namespace
 	)
@@ -57,8 +59,8 @@ func NewRootCommand() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			config.Burst = 30
-			config.QPS = 20.0
+			config.Burst = burst
+			config.QPS = qps
 
 			namespace, _, err := clientConfig.Namespace()
 			if err != nil {
@@ -98,6 +100,8 @@ func NewRootCommand() *cobra.Command {
 	command.Flags().IntVar(&glogLevel, "gloglevel", 0, "Set the glog logging level")
 	command.Flags().IntVar(&workflowWorkers, "workflow-workers", 32, "Number of workflow workers")
 	command.Flags().IntVar(&podWorkers, "pod-workers", 32, "Number of pod workers")
+	command.Flags().IntVar(&burst, "burst", 30, "Maximum burst for throttle.")
+	command.Flags().Float32Var(&qps, "qps", 20.0, "Queries per second")
 	command.Flags().BoolVar(&namespaced, "namespaced", false, "run workflow-controller as namespaced mode")
 	command.Flags().StringVar(&managedNamespace, "managed-namespace", "", "namespace that workflow-controller watches, default to the installation namespace")
 	return &command

docs/scaling.md

@@ -12,6 +12,7 @@ You can scale the controller vertically:
 
 - If you have workflows with many steps, increase `--pod-workers`.
 - If you have many workflows, increase `--workflow-workers`. 
+- Increase both `--qps` and `--burst`.
 
 You will need to increase the controller's memory and CPU.