HDFS-12578. TestDeadDatanode#testNonDFSUsedONDeadNodeReReg failing in branch-2.7. Contributed by Ajay Kumar.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManagerTestUtil.java

@@ -233,7 +233,9 @@ public class BlockManagerTestUtil {
    * @param bm the BlockManager to manipulate
    */
   public static void checkHeartbeat(BlockManager bm) {
-    bm.getDatanodeManager().getHeartbeatManager().heartbeatCheck();
+    HeartbeatManager hbm = bm.getDatanodeManager().getHeartbeatManager();
+    hbm.restartHeartbeatStopWatch();
+    hbm.heartbeatCheck();
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java

@@ -137,7 +137,8 @@ public class TestDeadDatanode {
   public void testNonDFSUsedONDeadNodeReReg() throws Exception {
     Configuration conf = new HdfsConfiguration();
     conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
-    conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1);
+    conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY,
+        3000);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_STALE_DATANODE_INTERVAL_KEY,
             6 * 1000);
     try {