Manually remove a NameNode from existing HDFS HA cluster

This topic lists the steps to manually remove a NameNode from existing HDFS HA cluster.

1. Stop the existing HDFS Transparency NameNodes.

   mmces service stop hdfs -N c16f1n07,c16f1n08

   or

   mmces service stop hdfs -a

2. Disable the CES HDFS services on the NameNode that you want to remove.

   mmchnode --ces-disable -N c16f1n08

3. Remove the NameNode related property from the hdfs-site.xml.

   For example, the existing HDFS HA cluster NameNode is c16f1n07(nn1) and c16f1n08(nn2). The NameNode that will be removed is c16f1n08.

   mmhdfs config del hdfs-site.xml -k 
   dfs.namenode.shared.edits.dir -k 
   dfs.namenode.rpc-address.cluster.nn2 -k 
   dfs.namenode.http-address.cluster.nn2

   mmhdfs config set hdfs-site.xml -k dfs.ha.namenodes.cluster=nn1

4. Upload the configuration into CCR.

   mmhdfs config upload

5. Start the existing HDFS Transparency NameNode.

   mmces service start hdfs

6. Check the HDFS NameNode status in the existing HDFS cluster.

   mmces service list -a

7. Restart DataNodes to take effective.

   mmhdfs hdfs-dn restart

8. Check DataNodes status.

   mmhdfs hdfs-dn status