Getting dumps of the MVS logger and coupling facility address spaces

For reliable diagnosis, it is important that you have dumps of the MVS logger address space and (if applicable) the coupling facility structures used by the system log.

Before you begin

This means that, before performing the diagnostic run, you will probably need to set a SLIP trap, as described in Setting a SLIP trap.

About this task

You need to set a SLIP if any of the following are true:
  • You have not applied MVS APAR OW27057.
  • MVS did not produce a dump of the logger address space.
  • MVS produced a dump of the logger address space but you have not kept the dump.
  • The CICS system log uses coupling facility log streams.
When specifying the SLIP, note the following:

Procedure

  1. Set the trap for the specific DFHLG07xx message that CICS issued when the original failure occurred.
    See the example SLIP in Figure 1.
    When the diagnostic run occurs and the failure repeats, the message will drive the SLIP.

    Occasionally, the DFHLG07xx message that was issued at the time of the original failure is not repeated during a diagnostic run. Instead, a different DFHLG07xx message is issued. Therefore the SLIP is not triggered. If this happens, perform another diagnostic run. This time, however, set the SLIP for the DFHLG07xx message that was issued during the first diagnostic run.

  2. Change the JOBLIST parameter in the example SLIP to read 
    JOBLIST=(IXGLOGR,XCFAS),
    You do not need to specify a dump of the CICS system, because one is taken automatically by the diagnostic run mechanism.
  3. Specify a dump of the MVS logger address space.
    See the example SLIP. If you have applied MVS APAR OW27057, and the original failure occurred because the MVS logger was unable to find a specific log stream block identifier, an extra dump may be produced.
  4. If the system log uses coupling facility log streams, specify a dump of the coupling facility structure.
    You can get the name of the structure from the two DFHLG0104 messages that were issued when CICS connected to DFHLOG and DFHSHUNT during the run in which the failure occurred.

    If DFHLOG and DFHSHUNT use separate coupling facility structures, dump both structures. Specify the names of both structures on the STRLIST parameter.

Example