In TPX proc replace SYSUDUMP DD with SYSMDUMP DD to capture a TPX SVC Dump in machine readable format

Products

• TPX - Session Management

Issue/Introduction

Broadcom Support recommends that TPXPROC started task JCL be updated in hlq.CB0VJCL to replace the SYSUDUMP DD 
statement with a SYSMDUMP DD statement. If a TPX internal failure occurs, SYSMDUMP writes a machine-readable dump 
of the system areas and the product address space to a data set, which Broadcom Support can use to troubleshoot 
the problem. 

Environment

Release : 5.4
Component : TPX for z/OS

Resolution

In the TPXPROC, replace the SYSUDUMP DD statement with the following SYSMDUMP DD statement:

//SYSMDUMP DD DISP=(NEW,DELETE,CATLG),                    
//           DSN=&TPREFIX..D&LYYMMDD..T&LHHMMSS..SYSMDUMP,
//           UNIT=SYSDA,SPACE=(CYL,(3000,200),RLSE),      
//           DCB=(RECFM=FB,LRECL=4160,BLKSIZE=0)          

Consider the following items when using this DD statement:

• The DISP parameter specifies (NEW,DELETE,CATLG) to allocate a new dump file 
   during the startup of a TPX region. This disposition automatically deletes unneeded
   dump files from normal runs and ensures that large amounts of space are not held for
   an empty file. 

• The file name must be unique. We recommend using dynamic system symbols
  or in-house-defined JCL symbols in the DSN parameter. The sample DD statement 
  above uses &LYYMMDD and &LHHMMSS to insert the time and date. Alternatively, 
  generate unique file names by specifying the file name as a generation data set (GDS).
  If the job produces multiple abends, use the special SYS1.SYSMDPxx file to capture
  only the first dump.

• If a DASD device is used, use the UNIT parameter to specify a group of esoteric devices.

• SYSMDUMP dump files can use striping and compression. Striping writes the dump more quickly. 
  Compression reduces the file size (and therefore uses less I/O resources). Extended format definitions can also be used
  or DSNTYPE=LARGE to accommodate large dump files.

 

Note: The size of the dump file depends on how much storage has been allocated to the MUF at the time of the dump.
          Because TPX dynamically allocates and releases storage as needed, an absolute value can not be calculated.
          We have recently received dumps from 4,000 to 60,000 tracks (250 to 4,000 cylinders), with one file 
          using 81,000 tracks (5,400 cylinders). 

After adding the SYSMDUMP DD statement, test that it works:

1. Edit the TPXPROC to change the REGION size to 2048K.
2. Start TPX.
   An abend occurs, most likely a U0001.
3. Verify that the abend created the SYSMDUMP file.
4. Edit the TPXPROC to restore the REGION size to 0M.