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 a node in Ambari, do the following:

  1. Access Apache Ambari.
  2. From the side toolbar, under Hosts, and then select the worker node to be decommissioned.
  3. From the list of components installed on that host, select Data Node.
  4. Click 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 click 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
  • To remove a node from a cluster from the OCI Console, complete the following:
    1. Open the navigation menu and click Analytics & AI. Under Data Lake, click Big Data Service.
    2. Under Compartment, select the compartment that contains the cluster.
    3. In the list of clusters, click the name of the cluster.
    4. On the Cluster details page, click the Actions menu (Actions Menu) for the node you want to delete, and then select Delete node.
    5. In the Delete node panel, enter the name of the node to delete.
    6. Select Force delete even when decommissioning fails to delete the node even when decommissioning of the node fails.
    7. Click 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 flags and variable options for CLI commands, see the Command Line Reference for Big Data.

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