15050: Limit number of containers that crunch-dispatch-local runs at a time

[arvados.git] / services / crunch-dispatch-local / crunch-dispatch-local.go

diff --git a/services/crunch-dispatch-local/crunch-dispatch-local.go b/services/crunch-dispatch-local/crunch-dispatch-local.go
index dcd54e8968e930f1cdb390aa9b0e5c40182c3bdb..36d149272ff5de2989a0defe7dcd6ec5a9b92eab 100644 (file)
--- a/services/crunch-dispatch-local/crunch-dispatch-local.go
+++ b/services/crunch-dispatch-local/crunch-dispatch-local.go
@@ -85,14 +85,15 @@ func doMain() error {
        }
        arv.Retries = 25
 
+       ctx, cancel := context.WithCancel(context.Background())
+
        dispatcher := dispatch.Dispatcher{
                Logger:       logger,
                Arv:          arv,
-               RunContainer: run,
+               RunContainer: (&LocalRun{startFunc, make(chan bool, 8), ctx}).run,
                PollPeriod:   time.Duration(*pollInterval) * time.Second,
        }
 
-       ctx, cancel := context.WithCancel(context.Background())
        err = dispatcher.Run(ctx)
        if err != nil {
                return err
@@ -123,7 +124,11 @@ func startFunc(container arvados.Container, cmd *exec.Cmd) error {
        return cmd.Start()
 }
 
-var startCmd = startFunc
+type LocalRun struct {
+       startCmd         func(container arvados.Container, cmd *exec.Cmd) error
+       concurrencyLimit chan bool
+       ctx              context.Context
+}
 
 // Run a container.
 //
@@ -133,13 +138,21 @@ var startCmd = startFunc
 //
 // If the container is in any other state, or is not Complete/Cancelled after
 // crunch-run terminates, mark the container as Cancelled.
-func run(dispatcher *dispatch.Dispatcher,
+func (lr *LocalRun) run(dispatcher *dispatch.Dispatcher,
        container arvados.Container,
        status <-chan arvados.Container) {
 
        uuid := container.UUID
 
        if container.State == dispatch.Locked {
+
+               select {
+               case lr.concurrencyLimit <- true:
+                       break
+               case <-lr.ctx.Done():
+                       return
+               }
+
                waitGroup.Add(1)
 
                cmd := exec.Command(*crunchRunCommand, uuid)
@@ -153,7 +166,7 @@ func run(dispatcher *dispatch.Dispatcher,
                // succeed in starting crunch-run.
 
                runningCmdsMutex.Lock()
-               if err := startCmd(container, cmd); err != nil {
+               if err := lr.startCmd(container, cmd); err != nil {
                        runningCmdsMutex.Unlock()
                        dispatcher.Logger.Warnf("error starting %q for %s: %s", *crunchRunCommand, uuid, err)
                        dispatcher.UpdateState(uuid, dispatch.Cancelled)