The XAKUSER exit is invoked during the activity keypointing process. You can use this exit to record, on the system log, user data that must be restored following an emergency restart. For further information about the use of the exit, see the CICS® Recovery and Restart Guide.
For best performance, journal control requests should not specify WAIT. CICS will force the records by writing a synchronous end of keypoint record upon return from the exit program.
Your exit program should be translated with the NOEDF option. Any program it links to should also be translated with this option. It is not possible to link to programs written in PL/I.
To ensure that it is called during every keypoint, your exit program should be enabled by means of a first phase PLTPI program--see Writing initialization programs. However, if it enabled at this stage, your program should not attempt to link to any program coded in COBOL or C, as it may be invoked before these are initialized.
Your exit program forms part of a critical CICS system activity. If it fails, CICS terminates.
Only the listed EXEC CICS commands are allowed in the XAKUSER exit. The exit should link only to other programs with the same restrictions.