J2EE Connector Architecture migration tips

Versions of WAS previous to V5.0 provided an initial implementation of the J2EE Connector Architecture (JCA) specification, V1.0. This implementation provided basic run time support based on the final JCA 1.0 Specification, but it was not a complete implementation.

V5.0 of the product provides a complete implementation of the JCA 1.0 Specification, which supports:

  • Connection sharing (res-sharing-scope).

  • Get/use/close programming model for connection handles.

  • Get/use/cache programming model for connection handles.

  • XA, Local, and No Transaction models of resource adapters, including XA recovery.

  • Security options A and C per the specification.

  • Applications with embedded .rar files

As of v6, the product provides a complete implementation of the JCA 1.5 Specification, which supports:

  • All the features of the JCA 1.0 Specification.

  • Deferred enlistment transaction optimization.

  • Lazy connection association optimization.

  • Inbound communication from an enterprise information system (EIS) to a resource adapter.

  • Inbound transactions from an EIS to a resource adapter.

  • Work management, which enables a resource adapter to put work on separate threads and to pass execution context (such as inbound transactions) to the thread .

  • Life cycle management, which enables a resource adapter to be stopped and started.

If you move from one of the earlier implementations of the J2EE Connector Architecture to the current implementation, be aware of the following:

  • This version of the product supports the res-sharing-scope tag within the resource reference (resource-ref) element. This tag was not available in previous versions and defaulted to shareable connections. Beginning with V5.0, WAS supports both shareable and unshareable connections.

  • The current product supports the Web container. Both enterprise bean and Web components can utilize the J2EE Connector Architecture.

  • Both connection handle usage patterns (get/use/close and get/use/cache) are supported. The get/use/close pattern indicates that a connection is retrieved, used, and closed all within the same transaction or method boundary. The get/use/cache pattern indicates that one can cache a connection across transaction or method boundaries.

  • The current version supports additional authentication mechanisms. The capability to support Options A and C per the JCA specification is provided, as well as support for res-auth settings of either Application or Container. In versions before V5.0, the res-auth setting was basically ignored, therefore it was treated as if res-auth was set to Application. If your existing applications have res-auth set to Container, they might behave differently if you install them into a current environment without any changes.

  • As of v6, resource authentication for res-auth settings of Container is preferably specified on the resource-reference mapping during application deployment. Specification of container-managed authentication on a data source or connection factory is deprecated.

  • As of V5.0, one can no longer specify pool and subpool names. The pool name is based on the data source or connection factory Java Naming and Directory Interface (JNDI) name. Subpools were eliminated to provide better performance.

  • As of v6, configuration data formerly in the j2c.properties file is now supported through the wsadmin scripting tool and the administration console. A migration utility updates the resources.xml file (or files) based on the settings in a j2c.properties file. A template j2c.properties file is no longer placed in the installed directory tree, but run-time code remains in place to process the file and favor its settings over those from the real configuration.

For applications that use Web services and JCA connectors, be aware that those generated on WebSphere Studio Application Developer -- Integration Edition V4.1.1 can run unchanged on WAS v6 only if they are regenerated using WebSphere Studio Application Developer -- Integration Edition V5.0 tools, or Rational Application Developer tools. This limitation is because of the wsd14j.jar file. As delivered in WAS Enterprise V4.1, the file is not fully compliant with JSR 110 (because JSR 110 was not final at the time that Version 4.1 shipped). The wsd14j.jar file shipped with WebSphere Application Server v6, of course, is compliant. However, because most of the classes have the same package names and interfaces, BUT NOT ALL, the two wsd14j.jar files cannot co-exist in the same WAS installation.

JDBC provider templates: important general migration tip

Always handle the jdbc-resource-provider-templates.xml file as read-only . When updating this file, special consideration should be taken. Before installing a PTF, you should save your updated jdbc-resource-provider-templates.xml file. After applying the PTF, you will need to verify that the new jdbc-resource-provider-templates.xml file has your correct entries. If the entries are not valid, you will have to merge your changes into this new jdbc-resource-provider-templates.xml file manually.

 

See Also


Resource adapter
Connection factory
Data sources
Unshareable and shareable connections
Connection handles