Configuring and Installing Optional Components › Tasks for Separately Licensed Components › Install the IMS Operations Facility › Rules to Address Complications

Rules to Address Complications

The IOF uses the following rules to address the complications:

Exit Combinations

Because IMS can have a combination of TYPE 1 and TYPE 2 exits, use the following guidelines. Remember, the TYPE 2 exit has complete control over whether the TYPE 1 exit is ever invoked.

• You have a user or OEM TYPE 1 exit but no TYPE 2 exit. The CA OPS/MVS supplied TYPE 2 exit must be installed.

  If your user or OEM TYPE 1 exit is called even when OPSMAIN is not running, the supplied OPSAOE00 assembler source code requires a minor modification. The instructions for making this modification are included in the source code. Make this modification before assembling and link editing the program into your IMS RESLIB.

• You have a user or OEM TYPE 2 exit but no TYPE 1 exit. In this case, the IOF TYPE 2 exit dynamically inserts itself into the IMS system you want the IOF to automate. It does not preclude you from using your own AOI exit, and your existing exit is still called.
• You have a user or OEM TYPE 2 exit, and you also have a user or OEM TYPE 1 exit. In this case, the IOF TYPE 2 exit monitors the reply code of your TYPE 2 exit. The reply code determines whether your TYPE 1 exit obtains control. This allows you to control your own TYPE 1 invocation of the exit. For a multisegment message, the IOF does not see the secondary segments if your TYPE 2 exit relinquishes control to your TYPE 1 segment.

To summarize, if your TM environment has neither a TYPE 1 or a TYPE 2 exit installed, the IOF requires the installation of its own TYPE 2 exit. The CA OPS/MVS supplied TYPE 2 exit, OPSAOE00 in OPS.CCLXASM, must be assembled, linked, and installed. If you have either one of the exits, IOF does not preclude you from using your own or OEM AOI exit (see the following restrictions).

Exit Restrictions

The IOF TYPE 1 exit has one restriction. The IOF uses the last 4 bytes of the UEHURSVD field in the IMS UEHB (User Exit Header Block) control block. You must, therefore, make sure that the AOI exit of your site does not also use this area. The sample AOI exit that ships with IMS does not use this area.

The IOF TYPE 2 exit has a restriction that is related to the IMS supplied AOE0WRKA AOI exit work area. The IOF uses the first 72 bytes and the last 20 bytes of this 256-byte work area. If you modify these areas in your own TYPE 2 EXIT, IOF overlays it and may cause your exit to fail. The IOF TYPE 2 exit always takes control first before any of your own or OEM TYPE 2 exit. For more information on the AOE0WRKA work area, see the IMS Customization Guide.

The CA OPS/MVS hooks for the IOF do not permit the user/OEM TYPE 1 or user/OEM TYPE 2 exits to suppress or delete IMS messages. Suppression, deletion, or both of IMS messages should be done in CA OPS/MVS message rules.

If you have your own TYPE 1 exit and need to install the CA OPS/MVS supplied TYPE 2 exit, OPSAOE00, do not install it ahead of time in your IMS RESLIB, unless CA OPS/MVS is operational and the INITIMS parameter is also turned on. Otherwise, it causes the user TYPE 1 exit to not be called.

If you have a conflict with our restrictions, contact Technical Support at http://ca.com/support.

Note: For more information, see the IMS Customization Guide and the IMS Application Programming: Transaction Manager.