Connection management architecture

The connection management architecture for both relational and procedural access to enterprise information systems (EIS) is based on the Java EE Connector Architecture (JCA) specification. The Connection Manager (CM), which pools and manages connections within an application server, 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 programming model.

Applications migrating from previous versions of WAS might experience some behavioral differences because of the specification 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 WebSphere Application Server 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 Version 4.0 application to Version 6.0 or later, using the latest migration tools, the application automatically uses the Version 4.0 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 WebSphere Application Server Version 4.0.

Subtopics

• Connection pooling
  Using connection pools helps to both alleviate connection management overhead and decrease development tasks for data access.

• Connection life cycle
  A ManagedConnection object is always in one of three states: DoesNotExist, InFreePool, or InUse.

• Unshareable and shareable connections
  The application server supports both unshareable and shareable connections. An unshareable connection is not shared with other components in the application. The component using this connection has full control of this connection.

• Connection handles
  A connection handle is a representation of a physical connection. To use a backend resource, such as a relational database in WebSphere Application Server, you must get a connection to that resource. When you call the getConnection() method, you get a connection handle returned. The handle is not the physical connection. The physical connection is managed by the connection manager.

• Transaction type and connection behavior
  All connection usage occurs within the scope of either a global transaction or a local transaction containment (LTC) boundary. Each transaction type places different requirements on connections and impacts connection settings differently.

• Application scoped resources
  Use this page to view brief descriptions of the resources that are bundled with the application. We can view individual resource settings by clicking the resource name.

Related concepts

Relational resource adapters and JCA

Related tasks

Configure data access for the Application Client

Migrate applications to use data sources of the current Java EE Connector Architecture (JCA)

Passing client information to a database