diff --git a/src/crane/crane_master.go b/src/crane/crane_master.go
index 10805938af776d00ab797e18242e385eaf19d77b..6c701bb2af5fe5e24a4e4e8de9aa39eb4ffd0e55 100644
--- a/src/crane/crane_master.go
+++ b/src/crane/crane_master.go
@@ -297,7 +297,7 @@ func startNewJob() {
 			}
 		}
 	}
-	tempData = make([]interface{})
+	tempData = make([]interface{}, 0)
 	//wg.Wait()
 	// start spout goroutine
 	go runSpout()