X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/7c2aa951ed9e7d0010fd58d59dc1e98c9d5e2800..654560f15c684635f2331363f04ad4cb3e9663d6:/lib/controller/fed_collections.go

diff --git a/lib/controller/fed_collections.go b/lib/controller/fed_collections.go
index ab49e39d12..07daf2f90e 100644
--- a/lib/controller/fed_collections.go
+++ b/lib/controller/fed_collections.go
@@ -217,17 +217,15 @@ func fetchRemoteCollectionByPDH(
 	// returned to the client.  When that happens, all
 	// other outstanding requests are cancelled
 	sharedContext, cancelFunc := context.WithCancel(req.Context())
+	defer cancelFunc()
+
 	req = req.WithContext(sharedContext)
 	wg := sync.WaitGroup{}
 	pdh := m[1]
 	success := make(chan *http.Response)
 	errorChan := make(chan error, len(h.handler.Cluster.RemoteClusters))
 
-	// use channel as a semaphore to limit the number of concurrent
-	// requests at a time
-	sem := make(chan bool, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
-
-	defer cancelFunc()
+	acquire, release := semaphore(h.handler.Cluster.API.MaxRequestAmplification)
 
 	for remoteID := range h.handler.Cluster.RemoteClusters {
 		if remoteID == h.handler.Cluster.ClusterID {
@@ -238,9 +236,8 @@ func fetchRemoteCollectionByPDH(
 		wg.Add(1)
 		go func(remote string) {
 			defer wg.Done()
-			// blocks until it can put a value into the
-			// channel (which has a max queue capacity)
-			sem <- true
+			acquire()
+			defer release()
 			select {
 			case <-sharedContext.Done():
 				return
@@ -278,7 +275,6 @@ func fetchRemoteCollectionByPDH(
 			case success <- newResponse:
 				wasSuccess = true
 			}
-			<-sem
 		}(remoteID)
 	}
 	go func() {