PK72567; 6.0.2.31 6.1.0.19: Messaging engine continues running without database

PK72567 resolves the following problem:

ERROR DESCRIPTION:
When the database hosting the message store for a service integration bus messaging engine is taken down, for example for maintenance, the messaging engine continues to run and accept work.

Work which requires updates to the persisted data in the message store fails. These failures can occur in a large number of areas of the code, including when performing nonpersistent messaging as the messaging engine may need to use the message store to allocate a unique id to a message, or spill nonpersistent messages out of memory. This makes the behavior of the messaging engine unpredictable while the database is unavailable, and increases the risk of the messaging engine being in an inconsistent state when the database is restored.

USERS AFFECTED:
Users of the default messaging provider for WebSphere Application Server Version 6.0, Version 6.1 and Version 7.0.

PROBLEM DESCRIPTION:
Stopping the database while the messaging engine is running can cause problems with the messaging engine runtime.

RECOMMENDATION:
None

The APAR introduces a custom property that allows you to change the behavior of the messaging engine when it loses its connection to the database.

The messaging engine custom property name is: sib.msgstore.jdbcFailoverOnDBConnectionLoss

There are two possible behaviors: - When the property is false the messaging engine continues to accept work from applications. It periodically attempts to regain the connection to the database. If work continues to be submitted to the messaging engine while the database is unavailable, the results can be unpredictable. This is the default behavior in V6.0 and V6.1.

- When the property is true, the messaging engine informs the high availability manager to terminate the application server process when the next "is alive" check takes place. If a node agent is monitoring the server and "Automatic restart" is enabled, the server automatically restarts. The messaging engine will be started by the high availability manager when an appropriate application server is available (according to the core group policy). This is the default behavior in V7.0 and later.

The above behavior only occurs when connectivity to a database is lost by a messaging engine which is running and has established exclusive access to its data store in the database.

It does not apply when a database is unavailable (or exclusive access cannot be established) during the startup of a messaging engine on an application server.

- The "Learning about data stores" section of the WebSphere Application Server information center.

PROBLEM CONCLUSION:
This APAR introduces the custom property.

The fix for this APAR is currently targeted for inclusion in Fix Pack 6.0.2.33, 6.1.0.23 and 7.0.0.1.

Please refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

For 6.1.0.19 PK74220 is a prerequisite.
For 6.0.2.31 there are no prerequisites

Please review the readme.txt for detailed installation instructions.