SET_LOAD_BALANCE_POLICY

Sets how native connection load balancing chooses a host to handle a client connection.

This is a meta-function. You must call meta-functions in a top-level SELECT statement.

Behavior type

Syntax

SET_LOAD_BALANCE_POLICY('policy')

Parameters

policy

The name of the load balancing policy to use, one of the following:

• NONE (default): Disables native connection load balancing.

• ROUNDROBIN: Chooses the next host from a circular list of hosts in the cluster that are up—for example, in a three-node cluster, iterates over node1, node2, and node3, then wraps back to node1. Each host in the cluster maintains its own pointer to the next host in the circular list, rather than there being a single cluster-wide state.

• RANDOM: Randomly chooses a host from among all hosts in the cluster that are up.

Note

Even if the load balancing policy is set on the server to something other than NONE, clients must indicate they want their connections to be load balanced by setting a connection property.

Privileges

Superuser

Examples

The following example demonstrates enabling native connection load balancing on the server by setting the load balancing scheme to ROUNDROBIN:

=> SELECT SET_LOAD_BALANCE_POLICY('ROUNDROBIN');
                  SET_LOAD_BALANCE_POLICY
--------------------------------------------------------------------------------
Successfully changed the client initiator load balancing policy to: roundrobin
(1 row)

See also