Configuring JDBC Resources for High Availability - Oracle WebLogic Server 12c Advanced Administration - page 83

Getting ready
This recipe will change the parameters of the ds-XA data source, so make sure the multi
data source and the individual data sources ds-XA-rac01 and ds-XA-rac02 have already
been created from the previous recipe.
How to do it...
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.
The multi data source does not provide failover for active and
in-use connections.
There's more...
The multi data source algorithm can be changed using WLST.