Configuring the IMS Log Write user exit

The OMEGAMON® Response Time Analysis (RTA) component uses the IMS LOGWRT user exit to pass IMS log buffers from IMS to the OMEGAMON collection address space. The RTA component reads the IMS log records to compute application response time metrics, which can be viewed on the OMEGAMON for IMS Classic interface and OMEGAMON enhanced 3270 user interface.

About this task

Other products might also want to use this LOGWRT user exit, so take the proper approach for the configuration. The following different installation options are provided:
  • Stand-alone exit
  • IMS multi-user exit, which is the preferred option for IMS V13 and above environments

Procedure

Choose a proper installation option and complete the steps for the configuration:

  • Stand-alone exit.
    The rtehilev.RKANMODR data set contains member DFSFLGX0, which is the member name that IMS searches for during startup. Then, the DFSFLGX0 module loads KRILGX?0, which is responsible for transferring IMS log buffers to the OMEGAMON collection address space.
    1. Add the rtehilev.RKANMODR data set to the IMS Control Region's STEPLIB concatenation.
      Note: Ensure that the DFSFLGX0 module in this library is concatenated before any other same named module.
    2. After the IMS Control Region JCL is updated, recycle the IMS system to activate the OMEGAMON LOGWRT user exit support.
  • IMS multi-user exit.
    1. If you have another, non-OMEGAMON, exit of the same type which has a DFS* name or alias and you do not specify this exit in the DFSDFxxx member, this may cause a duplicate-name conflict with OMEGAMON. To prevent the conflict, you have two options. The first option is to concatenate the library containing the non-OMEGAMON exit before the OMEGAMON library; The other option is to delete the DFS* alias of the OMEGAMON exit prior to recycling the IMS. This can be done using the sample JCL in xKANSAM(KOIXDFSA). Note that the DFS* alias for this exit is provided for backward compatibility with installations using the stand-alone exit option. Any future maintenance applied to this exit will again contain the DFS* alias which will then also need to be deleted.
    2. Add the rtehilev.RKANMODR data set to the IMS Control Region's STEPLIB concatenation.
    3. Add the LOGWRT user exit definition to the IMS PROCLIB member DFSDFxxx: 
      EXITDEF=(TYPE=LOGWRT,EXITS=(KRIFLGX0))
      Note: The Omegamon KRIFLGX0 LOGWRT Exit supports the IMS REFRESH USEREXIT Type-2 command and therefore is dynamically refreshable.
    4. After the IMS Control Region JCL is updated, recycle the IMS system to activate the OMEGAMON LOGWRT user exit support.

Results

The following message is written to the z/OS® Console when the OMEGAMON LOGWRT user exit is successfully initialized by using any of the preceding options:
KOIR1100I OMEGAMON RTA LOGWRT EXIT ACTIVATED FOR IMSID=IC1C