Adding a NameNode HA to an existing cluster with federated NameNodes requires updating
the cluster configuration, propagating the update to all the nodes in the cluster, starting
the new NameNodes, and refreshing the DataNodes to identify the new NameNodes.
-
Add
dfs.nameservices to hdfs-site.xml of the
NameNodes that you want to include in the federation.
-
For the active NameNode and its corresponding standby node, update the
configuration with the NameService ID suffix.
-
Add the configuration for the new NameNodes to the cluster configuration
file.
For more information about steps 1, 2, and 3; see .
-
Propagate the configuration file updates to all the nodes in the cluster.
-
Start the new active NameNode and its standby node.
-
Refresh the DataNodes in the cluster to identify the new NameNodes.
hdfs dfsadmin -refreshNamenodes <datanode_host_name>:<datanode_rpc_port>
