Manually failing over to the standby NameNode

If you are running a HDFS service with HA enabled, you can manually cause the active NameNode to failover to the standby NameNode. This is useful for planned downtime—for hardware changes, configuration changes, or software upgrades of your primary host.

  1. Go to the HDFS service.
  2. Click the Instances tab.
  3. Click Federation and High Availability.
  4. Locate the row for the Nameservice where you want to fail over the NameNode.
    Multiple rows display only when using HDFS federation.
  5. Select Actions > Manual Failover.
  6. From the pop-up, select the NameNode that should be made active, then click Manual Failover.
  7. Click Finish.
Cloudera Manager transitions the NameNode you selected to be the active NameNode, and the other NameNode to be the standby NameNode. HDFS should never have two active NameNodes.