Creating an Active Standby Node

You can create active standby nodes at the same time that you create your database or at a later time.

Note: When you create an active standby node, be sure to add any necessary storage locations. For more information, refer to Adding Storage Locations.

Creating an Active Standby Node with a New Database

  1. Create a database, including the nodes that you intend to use as active standby nodes.
  2. Using vsql, connect to a node other than the node that you want to use as an active standby node.
  3. Use the ALTER NODE SQL statement to convert the node from a permanent node to an active standby node. The following example shows a typical alter node command.
    => ALTER NODE v_mart_node5 STANDBY;
    Once you issue the ALTER NODE statement, the affected node goes down and restarts as an active standby node.

Creating an Active Standby Node with an Existing Database

When you are creating a new node with the intent of making it into an active standby node, shift the new node to ephemeral status as quickly as possible to prevent the cluster from moving data to the new node.

  1. Add a new node to your database. Do not rebalance the database.
  2. Using vsql, connect to a node other than the node that you want to use as an active standby node.
  3. Use the ALTER NODE SQL statement to convert the node from a permanent node to an ephemeral node. For example, the following command would set v_mart_node5 to a node type of ephemeral.
    => ALTER NODE v_mart_node5 EPHEMERAL;
  4. Rebalance the cluster to move any data from the ephemeral node.
  5. Use the ALTER NODE SQL statement to convert the node from an ephemeral node to an active standby node. The following example shows v_mart_node5 moving from ephemeral status to standby status.
    => ALTER NODE v_mart_node5 STANDBY;