Collecting a standalone database logger trace dynamically using z/OS UNIX

Under z/OS® UNIX System Services (z/OS UNIX), you can use the fteSetLoggerTraceLevel command to collect trace from a running logger. This can be very useful if IBM® Support need to see a trace from a logger that cannot be stopped.

1. Turn trace on for the logger, by running the following command:

   fteSetLoggerTraceLevel -traceLogger classes=level logger_name

   The -traceLogger parameter determines the internal classes and packages that are to be traced. Unless otherwise specified by your IBM Support representative, set this property to the value com.ibm.wmqfte=all.

2. Reproduce the issue.
3. Turn trace off for the logger, by running the following command:

   fteSetLoggerTraceLevel -traceLogger =off logger_name

4. If a logger is busy, then the trace files might wrap quickly and overwrite the information needed to investigate the issue.
   If you can stop the logger for a short period of time, complete the following steps to reduce the amount of trace data that is collected. Otherwise, contact IBM Support and discuss alternative trace specifications to reduce the amount of trace data that is collected.
   1. Schedule some time to stop the logger.
   2. Locate the logger.properties file for the logger that needs to be traced.

      The logger.properties file can be found in the BFG_DATA/mqft/config/coordination_qmgr_name/loggers/logger_name directory.

   3. Edit the file and add entries for the following properties:
      
      traceFiles=number_of_trace_files_to_use
      traceSize=size_of_each_trace_file_in_MB

      The traceFiles and traceSize properties are used to control the amount of trace data that is collected.

      The default value of the traceFiles property is 5, and the traceSize property has the default value of 20MB. This means that if you turn on trace dynamically, and you have not set the properties, the agent writes trace information to 5 wrapping trace files, each with a maximum size of 20MB.

      You should set these properties to large values, to collect as much trace data as possible.

      For example, to collect 1GB of wrapping trace, add the following lines to the logger.properties file:

      traceFiles=5
      traceSize=200
      

      This results in the logger writing trace data to a maximum of 5 files, where each file has a size of 200MB.

      For more information on these logger properties, see The MFT logger.properties file.

   4. Stop the logger, by running the fteStopLogger command.
   5. Start the logger, by running the fteStartLogger command.
   6. Turn trace on for the logger, by running the following command:

      fteSetLoggerTraceLevel -traceLogger trace_specification logger_name

   7. Reproduce the issue.
   8. Turn trace off for the logger, by running the following command:

      fteSetLoggerTraceLevel -traceLogger =off logger_name