HDFS-12659. Update TestDeadDatanode#testNonDFSUsedONDeadNodeReReg to increase heartbeat recheck interval. Contributed by Ajay Kumar.

(cherry picked from commit 11a7729c1474aa379a62c0440c8c1a11be261a75)

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

@@ -186,7 +186,8 @@ 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);
     long CAPACITY = 5000L;