Set timeout for master and volume non-streaming rpc

weed/server/master_server_handlers_admin.go

@@ -7,6 +7,7 @@ import (
 	"math/rand"
 	"net/http"
 	"strconv"
+	"time"
 
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/operation"
@@ -24,7 +25,10 @@ func (ms *MasterServer) collectionDeleteHandler(w http.ResponseWriter, r *http.R
 	}
 	for _, server := range collection.ListVolumeServers() {
 		err := operation.WithVolumeServerClient(server.Url(), func(client volume_server_pb.VolumeServerClient) error {
-			_, deleteErr := client.DeleteCollection(context.Background(), &volume_server_pb.DeleteCollectionRequest{
+			ctx, cancel := context.WithTimeout(context.Background(), time.Duration(5*time.Second))
+			defer cancel()
+
+			_, deleteErr := client.DeleteCollection(ctx, &volume_server_pb.DeleteCollectionRequest{
 				Collection: collection.Name,
 			})
 			return deleteErr