WLS 12.1.2 and MultiTenant Databases
By Monica Riccelli-Oracle on Dec 16, 2013
Oracle WebLogic Server release 12.1.2 has integrated support for the Oracle Database 12c features, particularly Application Continuity, Transaction Guard, Database Resident Connection Pool, Multi Tenant Databases, and Global Data Services. WLS integration to these new 12c database features is described in this white paper WebLogic 12c integration to Oracle Database 12c features.
The integration to Multi Tenant Database or Pluggable Database increases elasticity, scalability, and enables multitenancy. Pluggable Database implementations allow multiple distinct databases in a single, larger database installation. The Container Database (CDB) feature in Oracle Database 12c minimizes the overhead of these multi-database configurations by consolidating them into a single database with multiple Pluggable Databases (PDB) in a single Container Database. For more information about using this feature in WLS, see https://blogs.oracle.com/WebLogicServer/entry/part_3_12c_database_and
In Oracle WebLogic Server, you can use a single data source to pool connections to multiple pluggable databases. The application at run time can switch between PDB's by calling ALTER SESSION SET CONTAINER. This model provides the benefits of the Multi Tenancy option at the mid tier in addition to the data tier, including scalability and elasticity.
You should be aware of some limitations of PDB switching with Oracle Database 12.1. The following WebLogic Server limitations exist when using tenant switching.
Oracle RAC Fast Application Notification (FAN) is not supported. Even though FAN is not supported, Active GridLink still provides the benefit of a single data source view of multiple RAC instances and the ability to reserve connections on new instances as they are available without reconfiguration using connection load balancing. If you want to use tenant switching with an Active GridLink data source, “FAN enabled” must be set to false see http://docs.oracle.com/middleware/1212/wls/JDBCA/gridlink_datasources.htm#CHDIAGEF . Generic data sources don’t use FAN so this restriction doesn’t apply.
Database Resident Connection Pool (DRCP) is not supported
Application Continuity is not supported.
Proxy authentication is not supported.
Recovery of XA transactions in single data source that is used for switching between multiple PDB's is not supported.
For more details about these limitations read the documentation http://docs.oracle.com.middleware/1212/wls/JDBCA/ds_oracledriver.htm#CCHBDGHC.