Collect troubleshooting data for a Dead Letter Queue problem in IBM MQ for z/OS

• Collecting general data for all problems
• Collecting troubleshooting data for this problem
• Troubleshooting hints and tips
• Exchanging data with IBM Support

Collecting general data for all problems

A complete description of the problem, including the following:

• IBM MQ version, release, and maintenance level
• Operating system version, release, and maintenance level
• Related products version, and release levels if applicable
   

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Collecting troubleshooting data for this problem

Required (MustGather) data:

• Error Log
• Browse of the messages on the dead letter queue. On z/OS, there are several ways to browse the message on the DLQ:
  
  
  • - Use the Message Handler Sample. Program CSQ4TCH3 formats the contents of the Dead Letter Header (DLH) like the now-withdrawn SupportPac MA17 did.
    - Use sample JCL CSQ4BCGR to run CSQ4BCG0, which is the browse-mode version of CSQ4BCG1.
    - Use a vendor or in-house program that displays the DLH in addition to the message data.

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Troubleshooting hints and tips

• Search the IBM MQ Support site for known problems by using symptoms like the message number and error codes.
• Gather the documentation and work with the IBM MQ Support Team to resolve your problem.

Determine why a message is on the DLQ (dead letter queue):

1. Browse the message on the dead letter queue by using a program that shows headers, such as CSQ4BGC0 in SCSQLOAD with sample JCL in SCSQPROC. See sample output below.
    
2. Locate the dead letter header. The dead letter header starts with the characters "DLH".
   444C 4820 0000 0001 0000 010A 4D59 2E51 'DLH ........MY.Q'
    
3. Find the dead letter Reason (the reason the message arrived on the DLQ) in the third word in the dead letter header.
   In this example the dead letter Reason is:

   x'0000 010A'

4. Convert hex x'0000 010A' to decimal 266.

5. Use the dead letter reason code to determine why the message was placed on the dead-letter queue. The deal letter reason code is a Reason Code (MQRC_*) or a Feedback Code (MQFB_*).
   Examples:
   MQFB_TM_ERROR  266  X'0000010A'
   MQRC_Q_FULL   2053  X'00000805'
    

For a list of reason codes, see Reason Codes

For a list of feedback codes, see Feedback Codes

Learn more about this component:

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Exchanging data with IBM Support

• See Exchanging information with IBM Software Support for FTP and email instructions.
• Go to the IBM My Support site to open or update a case.       

  Note: Always update your case to indicate that data was sent

• If you need to speak with IBM Software Support, contact your country representative. If you need to speak with IBM Software Support in the US, you can call 1-800-IBM-SERV.
   

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