PostgreSQL (Patroni, HAProxy, or external load balancer) configuration

Scenario

A cluster of PostgreSQL nodes is managed by Patroni, and is typically accessed through a load balancer (LB) or a virtual IP (VIP).

Best practice

Use a validation query to ensure that the connection has not been silently interrupted by the load balancer. The following example shows the XML configuration:

<dataSource id="twsdb" jndiName="jdbc/twsdb">
                <connectionManager 
                minPoolSize="5" 
                maxPoolSize="50" 
                preTestConnection="true"/>
                <properties.postgresql 
                serverName="pg-load-balancer.example.com" 
                portNumber="5432" 
                databaseName="TWS"/>
                </dataSource>