Generating WebSphere MQ CHIN trace on IBM z/OS

Resolving The Problem

Before Tracing

Check the trace table (TRAXTBL) size and status, and if necessary increase the size to capture the problem. To determine the trace table size and status, run the following commands, where /cpf refers to the command prefix for the WebSphere MQ subsystem:

Checking the trace table size and status


/cpf DISPLAY QMGR TRAXTBL

/cpf DISPLAY TRACE

You can increase the size of the trace by running the following command, where xxx is an integer from 2 to 2048 (default: 2) indicating the number of megabytes to use. This command sends a message to the CHIN which frees the existing trace data space (if there is one) and allocates one of the new size:

Setting the trace table size


/cpf ALTER QMGR TRAXTBL(xxx)

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Generating a WebSphere MQ CHIN trace

1. Start trace using the command below, where /cpf refers to the command prefix for the WebSphere MQ subsystem. This command will not work unless both the command server and channel initiator are running:
   
   

   Starting CHIN trace

   
   /cpf START TRACE(CHINIT)
   
   
   
   
2. Recreate the problem, then capture the trace in a dump that includes the trace data space (CSQXTRDS). In these examples, replace ssid with the subsystem id of your queue manager, and nn with the reply numbers from the IEE094D messages on your system:
   
   

   Dumping the MSTR and CHIN jobs and the CHIN trace data space

   
   /DUMP COMM=(MQ MSTR & CHIN DUMP)
   /R nn,JOBNAME=(ssidMSTR,ssidCHIN),CONT
   /R nn,SDATA=(CSA,RGN,PSA,SQA,LSQA,TRT,SUM),CONT
   /R nn,DSPNAME=('ssidCHIN'.CSQXTRDS),END
   
   
   Check the syslog for an IEA611I or IEA911E message to be sure the dump is complete. Refer to the additional information below for examples which show how to include application jobs and coupling facility structures in the dump.
   
   
   
3. Optionally, stop trace:
   
   

   Stopping CHIN trace

   
   /cpf STOP TRACE(CHINIT)
   
   
   
   The CHIN will trace automatically when it starts, using trace number 0, if TRAXSTR(YES) is set using the ALTER QMGR command. In order to stop this trace, you must specify it explicitly by trace number:
   
   

   Stopping CHIN automatic trace

   
   /cpf STOP TRACE(CHINIT) TNO(0)
   
   
   
   
4. Format the trace. WebSphere MQ CHIN trace information can be displayed on-line or in batch as described at the links below. Enter one of the following IPCS commands, where ssid is the subsystem identifier:
   
   

   Formatting CHIN trace using VERBX

   
   VERBX CSQWDPRD 'SUBSYS=ssid,CTRACE=F'
   
   
   

   Formatting CHIN trace using CTRACE

   
   CTRACE COMP(CSQXssid),FULL
   
   



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Additional Information





WebSphere MQ V8.0

• Using the z/OS DUMP Command (example dump commands)
• Include the WebSphere MQ dump formatting member
• Formatting a Dump from the Channel Initiator
• The Channel Initiator Trace
• Processing a Dump in IPCS Using Batch
• Problem determination on z/OS

WebSphere MQ V7.1

• Using the z/OS DUMP Command (example dump commands)
• Include the WebSphere MQ dump formatting member
• Formatting a Dump from the Channel Initiator
• The Channel Initiator Trace
• Processing a Dump in IPCS Using Batch
• z/OS Problem Determination Guide



WebSphere MQ V7.0.1

• Using the z/OS DUMP Command (example dump commands)
• Include the WebSphere MQ dump formatting member
• Formatting a Dump from the Channel Initiator
• The Channel Initiator Trace
• Using IPCS in Batch
• z/OS Problem Determination Guide

WebSphere MQ V6.0

• WebSphere MQ for z/OS V6.0 Problem Determination Guide
  Chapter 8: Using the z/OS DUMP Command (example dump commands)
  Chapter 9: Formatting a WebSphere MQ for z/OS Dump
  Chapter 9: Using IPCS in Batch
  Chapter 10: The Channel Initiator Trace
• Include the WebSphere MQ dump formatting member: WebSphere MQ for z/OS V6.0 System Setup Guide Chapter 2, Task 21




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