Message Broker and WTX integration :Running multiple instances of maps with message flow

Running multiple instances of maps

              There are some restrictions you should note when you use a precompiled map concurrently in more than one broker message flow, or when you use a map in a broker message flow with multiple threads of execution. You allocate multiple threads by setting the message flow's Additional Instances property in the broker archive editor in the WebSphere Message Broker Toolkit.

- If you have used Map Settings to switch map audit on, and are using an AuditLocation of "File," then you must set the audit FileName to "Unique." Failure to do so causes the map to fail with error code 53, and to throw an exception.

- If you have used Map Settings to specify a WorkSpace of "File," which is the default, then you must set the WorkFilePrefix to "Unique." Failure to do so causes the map to fail with error code 36, and to throw an exception.

- If you have used Map Settings to switch map trace on, then only the first message flow thread that runs traces to the designated file. Other message flows and other threads fail to trace. Note that the map does not fail, and it does not throw an exception. It is not possible for you to specify "Unique" for the trace FileName.

- If you have used Edit Input Card or Edit Output Card to switch backup on for a card, then you must set the backup FileName to "Unique." Note that the map does not fail, and it does not throw an exception.

There are additional restrictions you should note when you use a map in a broker message flow with multiple threads of execution.

- Enable map caching by selecting the Map cache property in the Basic tab under Properties for the WTX Map node in the WebSphere Message Broker Toolkit. Failure to do so might cause the map to fail.