Configuring JDBC Resources for High Availability - Oracle WebLogic Server 12c Advanced Administration - page 79

17. Finally, click on the Activate Changes button.
How it works...
The multi data source ds-XA was created with the data sources ds-XA-rac01
and ds-XA-rac02 as members.
The multi data source manages the application requests for a database connection
and uses Algorithm Type to define the strategy for high availability.
If using the Failover algorithm, be sure to enable the Failover Request if
Busy checkbox of the multi data source.
The multi data source is responsible for managing the load and failover; so if the Oracle
database uses the SCAN address feature, it's recommended to set up a GridLink data
source instead.
It is still possible to use the SCAN address with the multi data source by
defining the instance name in the data source URL. Also, data source
members of a multi data source must always target to a unique Oracle RAC
node, so using JDBC URL parameters such as LOAD_BALANCE=ON and
FAILOVER=ON is not supported when using XA multi data sources.
The Oracle driver class name used for XA data sources is oracle.jdbc.xa.client.
OracleXADataSource .