Oracle Cloud Infrastructure Documentation

Removing a Node from a Cluster

Remove a node from a Big Data Service cluster.

Note

When you remove a node, Big Data Service decommissions the node before deleting it. However, if the decommissioning process doesn't finish in the 40-minute time limit, the request fails. Time taken to decommission a node depends on the number of blocks in the node that need to be moved. Therefore, we recommend that you decommission a node before removing it from the cluster.

To decommission and remove a node in Ambari, do the following:

  1. Access Apache Ambari.
  2. From the side toolbar, under Hosts, select the worker node to be decommissioned.
  3. From the list of components installed on that host, select Data Node.
  4. Select the Action icon, and then select Decommission.
  5. If the host has Node Manager Region Server or HttpFS installed, then decommission them.
  6. From the side toolbar, under Services select HDFS. Before moving to the next step, ensure the following:
    • In the Components section, DATANODES STATUS > Decommissioning is 0.
    • In the Service Metrics section, BLOCKS > Under Replicated is 0.
    Verify node decommission in Ambari
  7. Stop all components on the node from Ambari .
  8. Run the following command from the node to stop ambari-agent.
    ambari-agent stop
  9. Remove the node from Ambari: From HOST ACTIONS, select Delete Host.
    Delete Host option in Ambari
  10. Follow the Console instructions on this page to delete the node using Force delete even when decommissioning fails.
  • To remove a node from a cluster from the OCI Console, complete the following:
    1. On the Clusters list page, select the cluster that you want to work with. If you need help finding the list page or the cluster, see Listing Clusters in a Compartment.
    2. On the details page, select Nodes, then select the name of a node you want to work with.
    3. From the Actions menu (three dots) for the node, select Delete node.
    4. In the Delete node panel, enter the cluster admin password.
    5. Select Force delete even when decommissioning fails to delete the node after it's gracefully decommissioned and deleted from Ambari.
    6. Select Delete.

  • Use the oci bds instance remove command and required parameters to remove a single node from a cluster.

    oci bds instance remove --bds-instance-id <bds_instance_id> --cluster-admin-password <cluster_admin_password> --node-id <node_id> [OPTIONS]

    For a complete list of parameters and values for CLI commands, see the CLI Command Reference.

  • Use the RemoveNode operation to remove a single node from a cluster.