This is documentation for MapR Version 5.0. You can also refer to MapR documentation for the latest release.

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The procedure for removing a role from a node depends on the type of role you want to remove:

Removing a Role other than Fileserver, CLDB, or ZooKeeper 

To remove a role other than Fileserver, CLDB, or ZooKeeper, follow the procedure in this section. 

  1. To remove the NFS role, unmount any existing client mounts before proceeding to step 2, which stops the service (MapR NFS in this case). Removing the NFS role from a node affects any Virtual IP (VIP) pools that include this node.

  2. Stop the service for the role you want to remove from the MapR Control System (MCS) or with a maprcli command. The following example stops the HBase master service:

    % maprcli node services -hbmaster stop -nodes mapr-node1 
     

  3. Purge the role packages with the apt-getyum, or zypper commands, depending on your operating system.
  4. Run the configure.sh script with the -R option on the node where you removed the role.
    Warden picks up the new configuration automatically. 

  5. Restart Warden on the node where you removed the role.

    % service mapr-warden restart 

Removing a CLDB Role

To remove the CLDB role from a node, perform the following steps:

  1. If you have only one CLDB node in the cluster, add the CLDB role to another node.
    When failover occurs after removal of the CLDB node, the new CLDB node becomes the master CLDB.
  2. Stop the CLDB service on the node.

     % maprcli node services -cldb stop -nodes mapr-node1
     
  3. Purge the CLDB package mapr-cldb with the apt-getyum, or zypper commands, depending on your operating system.
  4. Run configure.sh on the node where you removed the role. Use the -C option and provide the list of CLDB nodes that excludes the node where you removed the role.
  5. Run  configure.sh on all other nodes in the cluster. Use the -C option and provide the list of CLDB nodes that excludes the node where you removed the role.
  6. Start or restart Warden on the node where you removed the CLDB role.
  7. Perform a rolling restart of Warden on all other nodes. 

Removing a ZooKeeper Role

To remove a ZooKeeper role from a node, perform the following steps:

  1. Stop ZooKeeper on the node.

    % service mapr-zookeeper stop 
     
  2. Purge the ZooKeeper package mapr-zookeeper.
  3. Run configure.sh. Use the -Z option and provide the list of ZooKeeper nodes that excludes the node where you removed the role.  
  4. Perform a rolling restart of ZooKeeper on all other ZooKeeper nodes. 
    A rolling restart of ZooKeeper means restart ZooKeeper on each node, one at a time, pausing until the last restart finishes before beginning the next. Restart the ZooKeeper leader last.
  5. Verify that ZooKeeper is healthy and that the expected nodes adopted the ZooKeeper node.

    % service mapr-zookeeper qstatus
     
  6. Perform a rolling restart of Warden on all other nodes.
    Warden picks up the revised quorum.
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