Defining system dump data sets

CICS® produces a system dump using the z/OS SDUMP macro. An SDUMP dump of CICS is written to a z/OS system dump data set. You must define z/OS system dump data sets for recording CICS system dumps.

For information about the SDUMP macro and the associated dump data sets, see the information about SVC dump in z/OS MVS Diagnosis: Tools and Service Aids.

Procedure

  1. For the initial installation of CICS, define a system dump data set of between 5 and 10 MB.
    When normal operations begin, you can adjust this to suit your own installation's requirements.
  2. Change the SDUMP options using the z/OS CHNGDUMP command.
    You must thoroughly review your use of the CHNGDUMP command when setting up your CICS region.
    1. Use the MERGE function to ensure that the areas selected by CICS to dump are included in the system dump data set output.
    2. Use the ADD option to replace any options specified by CICS when issuing the SDUMP.
      This can result in partial dumps being taken to the system dump data set.

Results

When you start CICS for the first time, CICS uses system default values for the dump table options, and continues to use the system default values until you modify them. For more information about the default values, see What happens to a dump request if there is no dump table entry?.

What to do next

Setting dumping options
CICS has a dump table facility that enables you to control dumps. The dump table lets you:
  • Specify the type of dump, or dumps, you want CICS to record.
  • Suppress dumping entirely.
  • Specify the maximum number of dumps to be taken during a CICS run.
  • Control whether CICS is to terminate as a result of a failure that results in a dump.

See The system dump table and The dump code options you can specify.

Processing SDUMP dump data sets

You can process the SDUMP dump data set using the interactive problem control system (IPCS), either online under TSO or by submitting a batch job to print it.

IPCS is described in the z/OS MVS IPCS User's Guide. For information about the IPCS VERBEXIT parameters that you use with the CICS IPCS dump exit, see Using IPCS to format and analyze CICS dumps: Overview. See also Formatting system dumps.

Suppressing system dumps that precede ASRx abends
The system dump data sets can become full with unwanted SDUMPs that precede ASRA, ASRB, and ASRD abends (after message DFHAP0001 or DFHSR0001). Consider whether to suppress system dumps that precede ASRx abend. For details, see Suppressing system dumps that precede ASRx abends.