Oracle JDBC Universal Connection Pool and Oracle WebLogic Server Active GridLink for Oracle RAC leverage the load balancing functionality provided by an Oracle RAC database. Run-time connection load balancing requires the use of an Oracle JDBC driver and an Oracle RAC database.
The Universal Connection Pool and Oracle WebLogic Server Active GridLink for Oracle RAC are integrated to take advantage of Load Balancing Advisory information. Oracle introduced the Universal Connection Pool for JDBC in Oracle Database 11g release 184.108.40.206.0. Consequently, Oracle deprecated the existing JDBC connection pool, the Implicit Connection Cache, which was introduced in Oracle Database 10g release 1 for use with Oracle RAC databases. In addition to Oracle Database 12c, you can also use the Universal Connection Pool with Oracle Database 10g or Oracle Database 11g.
Run-time connection load balancing requires that FCF is enabled and configured properly. In addition, the Oracle RAC load balancing advisory must be configured with service-level goals for each service used by the connection pool. The connection load balancing goal should be set to
SHORT, for example:
srvctl modify service -db db_unique_name -service service_name -rlbgoal SERVICE_TIME -clbgoal SHORT
Oracle Universal Connection Pool for JDBC Developer's Guide for more information about configuring run-time connection load balancing for Universal Connection Pool