The message trace records all messages that are handled by JES XCF. The data is recorded at specific points in JES XCF processing from the time a JDU issues the IXZXIXSM macro through the time the receiving JDU issues the IXZXIXRM macro. Message tracing also traces acknowledgements that are returned to message senders.

This trace produces a high volume of data; therefore, you can optionally start and stop detailed message tracing.