[HDFS-6731] Run "hdfs zkfc-formatZK" on a server in a non-namenode will cause a null pointer exception.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.4-alpha, 2.4.0
• Fix Version/s: 2.6.0
• Component/s: auto-failover, ha
• Hadoop Flags: Reviewed
• Assignee: Masatake Iwasaki
• Reporter: WenJin Ma
• Created: 28/May/13 06:31
• Updated: 01/Dec/14 03:10
• Resolved: 23/Jul/14 02:15

Description

Run "hdfs zkfc-formatZK" on a server in a non-namenode will cause a null pointer exception.

[hadoop@test bin]$ ./hdfs zkfc -formatZK
Exception in thread "main" java.lang.NullPointerException
at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:187)
at org.apache.hadoop.hdfs.tools.NNHAServiceTarget.<init>(NNHAServiceTarget.java:57)
at org.apache.hadoop.hdfs.tools.DFSZKFailoverController.create(DFSZKFailoverController.java:128)
at org.apache.hadoop.hdfs.tools.DFSZKFailoverController.main(DFSZKFailoverController.java:172)

I look at the code, found in the org.apache.hadoop.hdfs.DFSUtil.getSuffixIDs () method does not make judgments on this issue.

static String[] getSuffixIDs(final Configuration conf, final String addressKey,
      String knownNsId, String knownNNId,
      final AddressMatcher matcher) {
    String nameserviceId = null;
    String namenodeId = null;
    int found = 0;
   //......do something

   if (found > 1) { // Only one address must match the local address
      String msg = "Configuration has multiple addresses that match "
          + "local node's address. Please configure the system with "
          + DFS_NAMESERVICE_ID + " and "
          + DFS_HA_NAMENODE_ID_KEY;
      throw new HadoopIllegalArgumentException(msg);
    }

    // If the IP is not a local address, found to be less than 1.
    // There should be throw an exception with clear message rather than cause a null pointer exception.       
    return new String[] { nameserviceId, namenodeId };

Issue Links

• is duplicated by: HADOOP-10545 hdfs zkfc NullPointerException