Often, when a user is having problems with WebSphere MQ one of the first questions asked by the IBM MQ support team is "Are there any FDC files?"

The terms FFST and FDC are sometimes used synonymously. These are files written by MQ to record errors and dump information about what occurred at the time MQ encountered the error.

FFST stands for First Failure Support Technology, and is technology within WebSphere MQ designed to create detailed reports with information about the current state of a queue manager together with historical data. These errors are written to files named as AMQxxxxx.y.FDC where xxxxx is the process ID (PID) that encountered the error. Hence, the *FDC files include the FFST reports. All threads in a process will append their FFSTs to the same file.

A useful tool is "ffstsummary". You simply type that command when you are in the /var/mqm/errors directory and it produces a summary of the FFST reports, sorted into time order.

Usually the first FDC that occurred at the time/date of the current problem is the most relevant. Other subsequent FDC files may be due to the resulting symptoms but not the actual root cause. This is why it is important to analyze the FDCs times to determine the origin of the problem.

I often redirect the output to a file for ease of review. Example:
$ ffstsummary > FFST.output

You can then view the FFST.output file and should see something like this:

!AMQ348308.0.FDC  2012/09/07 07:25:19.153937-4 amqzmur0     348308     1 XC034255 xcsWaitEventSem
!AMQ368680.0.FDC  2012/09/07 07:25:20.261858-4 amqzmgr0     368680     1 XC298255 xcsSelect
!AMQ405654.0.FDC  2012/09/07 07:25:21.363708-4 amqpcsea     405654     1 XC034255 xcsWaitEventSem

Using the information from the ffstsummary output, try to correlate the times to entries in the Queue Manager logs. Together this information is a good starting point for trying to troubleshoot a WebSphere MQ problem.

For example, the columns in the output above show:

• Filename - which FDC file contains the FFST report
• Time and Date of the report
• Process name - name of the process that produced the report (for example: amqpcsea)
• Probe id (In this example, the Probe IDs are XC034255 and XC298255)
• Component - part of WebSphere MQ where the report was produced

Once you have the Probe ID information from the FDC file and possibly a corresponding error code from the queue manager log, you can search online for possible matches to APAR, technotes, etc. to expedite your problem resolution.



Etiquetas:  error ffstsummary queue qmgr wmq fdc ffst mq websphere manager