Using WebSphere MQ for iSeries trace
Although you need to use certain traces on occasion, running the trace
facility slows your systems.
You also need to consider to what destination you want your trace information
sent.
Notes:
- To run the WebSphere MQ for iSeries trace commands, you must have the appropriate authority.
- Trace data is written to IFS only when trace is ended, with option *OFF.
- Trace data remains in the system until you delete it from the IFS.
Trace usage
There are two stages in using trace:
- Decide whether you want early tracing. Early tracing lets you trace the
creation and startup of queue managers. Note, however, that early trace can
easily generate large amounts of trace, because it is implemented by tracing all jobs for all queue managers.
To enable early tracing, use TRCMQM with the TRCEARLY parameter set to *YES.
- Start tracing WebSphere MQ work using TRCMQM *ON. To stop
the trace, you have two options:
- TRCMQM *OFF, to stop collecting trace records for
a queue manager. The trace records are written to files in the /QIBM/UserData/mqm/trace directory.
- TRCMQM *END, to stop collecting trace records for all queue managers and to disable early trace. This option
ignores the value of the TRCEARLY parameter.
You can also specify the level of detail you want, using the TRCLEVEL
parameter set to:
- *DFT
- For minimum-detail level for flow processing trace points.
- *DETAIL
- For high-detail level for flow processing trace points.
- *PARMS
- For default-detail level for flow processing trace points.
Selective trace
You can reduce the amount of trace data being saved, improving run-time
performance, using the command TRCMQM with F4=prompt,
then F9 to customize the TRCTYPE and EXCLUDE parameters:
- TRCTYPE
- Specifies the type of trace data to store in the trace file. If you
omit this parameter, all trace points except those specified in EXCLUDE are
enabled.
- EXCLUDE
- Specifies the type of trace data to omit from
the trace file. If you omit this parameter, all trace points specified in
TRCTYPE are enabled.
The options available on both TRCTYPE and EXCLUDE are:
- *ALL (TRCTYPE only)
- All the trace data as specified by the following keywords is stored
in the trace file.
- trace-type-list
- You can specify more than one option from the following keywords, but
each option can appear only once.
- *API
- Output data for trace points associated with the MQI and major queue
manager components.
- *CMTRY
- Output data for trace points associated with comments in the WebSphere MQ components.
- *COMMS
- Output data for trace points associated with data flowing over communications
networks.
- *CSDATA
- Output data for trace points associated with internal data buffers in
common services.
- *CSFLOW
- Output data for trace points associated with processing flow in common
services.
- *LQMDATA
- Output data for trace points associated with internal data buffers in
the local queue manager.
- *LQMFLOW
- Output data for trace points associated with processing flow in the
local queue manager.
- *OTHDATA
- Output data for trace points associated with internal data buffers in
other components.
- *OTHFLOW
- Output data for trace points associated with processing flow in other
components.
- *RMTDATA
- Output data for trace points associated with internal data buffers in
the communications component.
- *RMTFLOW
- Output data for trace points associated with processing flow in the
communications component.
- *SVCDATA
- Output data for trace points associated with internal data buffers in
the service component.
- *SVCFLOW
- Output data for trace points associated with processing flow in the
service component.
- *VSNDATA
- Output data for trace points associated with the version of WebSphere MQ running.
Wrapping trace
Use the MAXSTG parameter to wrap trace, and to specify the maximum size
of storage to be used for the collected trace records. The options are:
- *DFT
- Trace wrapping is not enabled. For each job, trace
data is written to a file with the suffix .TRC until tracing is stopped.
- maximum-K-bytes
- Trace wrapping is enabled. When the trace file reaches its maximum size,
it is renamed with the suffix .TRS, and a new trace file with suffix .TRC
is opened. Any existing .TRS file is deleted. Specify a value in the range
1 through 16 000.