Remove nodes from an AWS cluster

Use the following procedures to remove instances/nodes from an AWS cluster.

Use the following procedures to remove instances/nodes from an AWS cluster.

To avoid data loss, Vertica strongly recommends that you back up your database before removing a node. For details, see Backing up and restoring the database.

Remove hosts from the database

Before you remove hosts from the database, verify that you have:

  • Backed up the database.

  • Lowered the K-safety of the database.

To remove a host from the database:

  1. While logged on as dbadmin, launch Administration Tools.

    $ /opt/vertica/bin/admintools

  2. From the Main Menu, select Advanced Menu.

  3. From Advanced Menu, select Cluster Management. ClickOK.

  4. From Cluster Management, select Remove Host(s). Click OK.

  5. From Select Database, choose the database from which you plan to remove hosts. Click OK.

  6. Select the host(s) to remove. Click OK.

  7. Click Yes to confirm removal of the hosts.

  8. Click OK. The system displays a message telling you that the hosts have been removed. Automatic rebalancing also occurs.

  9. Click OK to confirm. Administration Tools brings you back to the Cluster Management menu.

Remove nodes from the cluster

To remove nodes from a cluster, run the update_vertica script and specify:

  • The option --remove-hosts, followed by the IP addresses of the nodes you are removing.

  • The option --ssh-identity, followed by the location and name of your *pem file.

  • The option --dba-user-password-disabled.

The following example removes one node from the cluster:

$ sudo /opt/vertica/sbin/update_vertica  --remove-hosts  --point-to-point  \
  --ssh-identity ~/name-of-pem.pem --dba-user-password-disabled

Stop the AWS instances

After you have removed one or more nodes from your cluster, to save costs associated with running instances, you can choose to stop the AWS instances that were previously part of your cluster.

To stop an instance in AWS:

  1. On AWS, navigate to your Instances page.

  2. Right-click the instance, and choose Stop.

This step is optional because, after you have removed the node from your Vertica cluster, Vertica no longer sees the node as part of the cluster, even though it is still running within AWS.