Connection management architecture
The connection management architecture for both relational and procedural access to enterprise information systems (EIS) is based on the JavaPlatform, Enterprise Edition (Java EE) Connector Architecture (JCA) specification.
The Connection Manager (CM), which pools and manages connections within an appserver, is capable of managing connections obtained through both resource adapters (RAs) defined by the JCA specification, and data sources defined by the JDBC 2.0 (and later) Extensions specification.
To make data source connections manageable by the CM, the WAS provides a resource adapter (the WebSphere Relational Resource Adapter) that enables JDBC data sources to be managed by the same CM that manages JCA connections. From the CM point of view, JDBC data sources and JCA connection factories look the same. Users of data sources do not experience any programmatic or behavioral differences in their applications because of the underlying JCA architecture. JDBC users still configure and use data sources according to the JDBC model.
Applications migrating from previous versions of WAS might experience some behavioral differences because of the spec changes from various Java EE requirements levels. These differences are not related to the adoption of the JCA architecture.
If we have J2EE 1.2 applications using the JDBC API that you wish to run in WAS 6.0 and later, the JDBC CM from Application Server version 4.0 is still provided as a configuration option. Using this configuration option enables J2EE 1.2 applications to run unaltered. If we migrate a V4.0 application to V6.0 or later, using the latest migration tools, the application automatically uses the V4.0 connection manager after migration. However, EJB 2.x modules in J2EE 1.3, J2EE 1.4 and Java EE applications cannot use the JDBC CM from WAS V 4.0.
Subtopics
Connection pooling
Connection life cycle
Unshareable and shareable connections
Connection handles
Transaction type and connection behavior
Application scoped resources
Related concepts
Relational resource adapters and JCA
Related tasks
Set data access for the Application Client
Migrate applications to use data sources of the current JavaEE Connector Architecture (JCA)
Passing client information to a database