Managing High Availability
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Modify HDFS configurations

You may need to modify your hdfs-site configuration and/or your core-site configuration.

Check whether you need to modify your hdfs-site configuration, by executing the following command on the Ambari Server host:

/var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] get localhost [CLUSTER_NAME] hdfs-site

If you see any of the following properties, you must delete them from your configuration.

  • dfs.nameservices
  • dfs.client.failover.proxy.provider.[NAMESERVICE_ID]
  • dfs.ha.namenodes.[NAMESERVICE_ID]
  • dfs.ha.fencing.methods
  • dfs.ha.automatic-failover.enabled
  • dfs.namenode.http-address.[NAMESERVICE_ID].nn1
  • dfs.namenode.http-address.[NAMESERVICE_ID].nn2
  • dfs.namenode.rpc-address.[NAMESERVICE_ID].nn1
  • dfs.namenode.rpc-address.[NAMESERVICE_ID].nn2
  • dfs.namenode.shared.edits.dir
  • dfs.journalnode.edits.dir
  • dfs.journalnode.http-address
  • dfs.journalnode.kerberos.internal.spnego.principal
  • dfs.journalnode.kerberos.principal
  • dfs.journalnode.keytab.file
Where [NAMESERVICE_ID] is the NameService ID you created when you ran the Enable NameNode HA wizard.
  1. Note - For Ambari 2.6.0 and higher, is not supported and will fail. Use instead.
  2. On the Ambari Server host, execute the following for each property you found:
    /var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] delete localhost [CLUSTER_NAME] hdfs-site [PROPERTY_NAME]
    Replace [PROPERTY_NAME] with the name of each of the properties to be deleted.
  3. Verify that all of the properties have been deleted:
    /var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] get localhost [CLUSTER_NAME] hdfs-site
    None of the properties listed above should be present.
  4. Determine whether you must modify your core-site configuration:
    /var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] get localhost [CLUSTER_NAME] core-site
  5. If you see the property ha.zookeeper.quorum, delete it:
    /var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] delete localhost [CLUSTER_NAME] core-site ha.zookeeper.quorum
  6. If the property fs.defaultFS is set to the NameService ID, revert it to its non-HA value:
    "fs.defaultFS":"hdfs://[name-service-id]" The property fs.defaultFS needs to be modified as it points to a NameService ID "fs.defaultFS":"hdfs://[]"
    You need not change the property fs.defaultFS, because it points to a specific NameNode, not to a NameService ID.
  7. Revert the property fs.defaultFS to the NameNode host value:
    /var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] set localhost [CLUSTER_NAME] core-site fs.defaultFS hdfs://[NAMENODE_HOSTNAME]
  8. Verify that the core-site properties are now properly set:
    /var/lib/ambari-server/resources/scripts/ -u [AMBARI_USER] -p [AMBARI_PW] -port [AMBARI_PORT] get localhost [CLUSTER_NAME] core-site
    The property fs.defaultFS should be the NameNode host and the property ha.zookeeper.quorum should not appear.
Re-create the standby NameNode.