Troubleshooting data for terminal hang problems

CICS® MustGather for terminal hang problems

Terminals hang with x-clock or other symptoms for many reasons, for example, application problems, emulators, or failure to follow SNA protocol.

Gather the following diagnostic information before contacting the CICS support team to troubleshoot your terminal hang problems.

Required data:
  1. The CICS message log that contains DFHZCnnnn messages for the terminal. Messages are written to the console or the CSNE transient data destination. If terminals are involved in transaction routing, collect the CICS message log for both the terminal owning region (TOR) and the application owning region (AOR). For more information, see CICS messages.
  2. The MVS™ system dump that is taken after the terminal is hung so control blocks such as the RPL and TCTTE can be analyzed. If terminals are involved in transaction routing, take an MVS system dump of both the TOR and the AOR. For more information, see Using dumps for CICS problem determination on z/OS®.
  3. The CICS internal trace that is included in the MVS system dump when tracing is active. Ensure that the internal trace table size is big enough to contain sufficient data for diagnosis; for example, you can use a table size of 20480K. Also, turn on level 1 tracing for all CICS components. If the problem is re-creatable, set the level of tracing to 1-2 for the AP, IS, and TC components. For more information, see Using trace for CICS problem determination on z/OS.
Optional data:
  1. If you want to identify a transaction that causes the terminal to hang and you need to keep a record of system actions over a long period of time, take the CICS auxiliary trace or the GTF Trace. For more information, see Using trace for CICS problem determination on z/OS.
  2. If the hang occurs at bind time (you never see the CICS good morning message), take a z/OS Communications Server (VTAM®) buffer trace of the logon application identifier (applid) to see the bind flow. Also, take a z/OS Communications Server exit trace (CICS VTAM exit trace), and a ZCP trace. For more information on the trace, see Using trace for CICS problem determination on z/OS, z/OS Communications Server exit tracing, and Specifying transaction and terminal-related trace options.
  3. If a specific DFHZCxxxx message appears to be the cause of the hang, you can add the message to the CICS system dump table. The following command is an example:
    CEMT SET SYD(ZC2403) MAX(1) ADD

    This produces a system dump at the time of the DFHZCxxxx message. The dump contains the trace that leads up to the failure. Ensure that MAX is 1 greater than CUR to capture a dump. Check this by entering CEMT INQ SYD(ZCxxxx).