Collecting data about VTAM-related DC problems

IMS DC-related problems are associated mainly with VTAM® or OTMA. Use these guidelines to collect diagnostic information about VTAM when you experience a problem.

VTAM dumps are often required to help diagnose problems, but are infrequently obtained by operations personnel. IMS NODE traces, VTAM BUFFER traces, and VTAM INTERNAL traces are often required, in conjunction with the IMS region dumps and VTAM dumps, to solve DC problems.

The IMS log tapes contain much of the transaction data that flows through IMS. This transaction data includes the following IMS records:

  • TYPE01
  • TYPE03 (MSG queue entries)
  • TYPE11 through TYPE16 (SPAs, DIALs, SIGN)

To start the recreate attempt after issuing an IMS /SWITCH OLDS command to have the related data placed on a new OLDS:

Procedure

  1. Issue the following IMS command and save the IMS console output: 
     /DIS NODE nodename
  2. Turn on the IMS NODE trace by issuing the following command. 
    /TRA SET ON NODE nodename
    Data is captured in the IMS TYPE6701 log record. Save the IMS online log data set input to the IMS utility programs DFSERA10 and DFSERA30.
  3. (Optional) Turn on the VTAM Buffer Trace and VTAM Internal Trace to complement the IMS NODE trace by issuing this series of commands: 
    F NET,TRACE,TYPE=BUF,ID=nodename
F NET,TRACE,TYPE=VTAM,MODE=EXT,
 OPT=(API,PIU,MSG)
    To capture these trace entries, GTF must be active with the USR option specified.
  4. Obtain a z/OS® dump of the IMS regions by issuing this series of commands: 
    DUMP COMM=(dump title)
R id JOBNAME=(j1,j2,j3,j4,j5,j6),
SDATA=(CSA,PSA,RGN,SQA,SUM,TRT),END
    j1
    IMS CTL or DBCTL region job name
    j2
    IMS DL/I region job name
    j3
    Suspicious IMS dependent region job name, if any
    j4
    Suspicious CCTL (CICS®) region name, if any
    j5
    IRLM region job name (if IRLM DB locking is used)
    j6
    DBRC region job name
    In the previous example,
  5. Obtain a dump of the VTAM address space by issuing this series of commands: 
    DUMP COMM=(dump title)
R id JOBNAME=(vtam jobname),
SDATA=(CSA,PSA,RGN,SQA,SUM,TRT),END
  6. Save the IMS log tapes created during the error period.