Removing Hosts From a Cluster

If a host that you removed from the database is not used by any other database, you can remove it from the cluster using the update_vertica script. You can leave the database running (UP) during this operation.

You can remove hosts from a database on the MC interface, but you cannot remove those hosts from a cluster.

Prerequisites

The host must not be used by any database.

Procedure to Remove Hosts

From one of the hosts in the cluster, run update_vertica with the –-remove-hosts switch. Provide a comma-separated list of hosts to remove from an existing Vertica cluster. You can specify a host by the host name or IP address of the system.

This example removes host01, host02, and host03 from the cluster:

# /opt/vertica/sbin/update_vertica --remove-hosts host01,host02,host03

The update_vertica script uses all the same options as install_vertica and:

• Modifies the spread to match the smaller cluster.
• Configures the Administration Tools to work with the smaller cluster.

Important Tips

• Do not include spaces in the hostname list provided with --remove-hosts if you specified more than one host.
• If a new RPM is specified with --rpm, then Vertica will first install it on the existing cluster hosts before proceeding.
• Use the same command line parameters as those used when you installed the original cluster. Specifically if you used non-default values for the database administrator username, password, or directory path, provide the same when you remove hosts; otherwise; the procedure fails. Consider creating a properties file in which you save the parameters during the installation, which you can reuse on subsequent install and update operations. See Installing Vertica Silently.