Adding Hosts to a Cluster

After you have backed up the database and configured the hosts you want to add to the cluster, you can now add hosts to the cluster using the update_vertica script.

You can use MC to add standby nodes to a database, but you cannot add hosts to a cluster using MC.

Prerequisites and Restrictions

If you installed Vertica on a single node without specifying the IP address or hostname (you used localhost), it is not possible to expand the cluster. You must reinstall Vertica and specify an IP address or hostname.

Procedure to Add Hosts

From one of the existing cluster hosts, run the update_vertica script with a minimum of the --add-hosts host(s) parameter (where host(s) is the hostname or IP address of the system(s) that you are adding to the cluster) and the --rpm or --deb parameter:

# /opt/vertica/sbin/update_vertica --add-hosts host(s) --rpm package

See Installing Vertica with the Installation Script for the full list of parameters. You must also provide the same options you used when originally installing the cluster.

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

  • Installs the Vertica RPM on the new host.
  • Performs post-installation checks, including RPM version and N-way network connectivity checks.
  • Modifies spread to encompass the larger cluster.
  • Configures the Administration Tools to work with the larger cluster.

Important Tips:

  • Consider using --large-cluster with more than 50 nodes.
  • A host can be specified by the hostname or IP address of the system you are adding to the cluster. However, internally Vertica stores all host addresses as IP addresses.
  • Do not use include spaces in the hostname/IP address list provided with --add-hosts if you specified more than one host.
  • If a package is specified with --rpm/--deb, and that package is newer than the one currently installed on the existing cluster, then, Vertica first installs the new package on the existing cluster hosts before the newly-added hosts.
  • Use the same command line parameters for the database administrator username, password, and directory path you used when you installed the cluster originally. Alternatively, you can create a properties file to save the parameters during install and then re-using it on subsequent install and update operations. See Installing Vertica Silently.
  • If you are installing using sudo, the database administrator user (dbadmin) must already exist on the hosts you are adding and must be configured with passwords and home directory paths identical to the existing hosts. Vertica sets up passwordless ssh from existing hosts to the new hosts, if needed.

  • If you initially used the --point-to-point option to configure spread to use direct, point-to-point communication between nodes on the subnet, then use the --point-to-point option whenever you run install_vertica or update_vertica. Otherwise, your cluster's configuration is reverted to the default (broadcast), which may impact future databases.

  • The maximum number of spread daemons supported in point-to-point communication and broadcast traffic is 80. It is possible to have more than 80 nodes by using large cluster mode, which does not install a spread daemon on each node.

Examples: 

--add-hosts host01 --rpm
--add-hosts 192.168.233.101
--add-hosts host02,host03