The multi data source has two strategy options for highly available connections for an Oracle RAC database. The strategy is defined by the Algorithm Type parameter.

Carry out the following steps to configure the high availability strategy for the multi data source:
  1. Access the Administration Console with your web browser at http://adminhost.domain.local:7001/console.
  2. Click on the Lock & Edit button to start a new edit session.
  3. Expand the Services tree on the left, and then click on Data Sources.
  4. Click on the ds-XA multi data source.
  5. Change Algorithm Type to Load Balance. Then click on the Save button.
  6. Finally, click on the Activate Changes button.

How it works...

With the Load Balance algorithm, the multi data source is responsible for load balancing the application requests to reserve a database connection in a round-robin fashion. If one Oracle RAC node goes down, the multi data source continues to return good connections transparently to the applications from the other RAC node.
The Failover algorithm returns a connection from the first data source of the member list. If the connection fails or all connections of the pool are in use, the other data source members will be used.

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