HADOOP-14166. Reset the DecayRpcScheduler AvgResponseTime metric to zero when queue is not used. Contributed by Surendra Singh Lilhore.

(cherry picked from commit dcf4559ebdb5bb11d03b264a9875bff316b89eef)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/DecayRpcScheduler.java

@@ -618,6 +618,8 @@ public class DecayRpcScheduler implements RpcScheduler,
         } else {
           responseTimeAvgInLastWindow.set(i, averageResponseTime);
         }
+      } else {
+        responseTimeAvgInLastWindow.set(i, 0);
       }
       responseTimeCountInLastWindow.set(i, responseTimeCount);
       if (LOG.isDebugEnabled()) {