Setting the tracing status

You can set the system tracing status by coding the appropriate system initialization parameters, and you can also set it dynamically, using the CETR transaction. The CETR transaction enables you to make changes in response to contingencies, as they arise.

Setting the tracing status at system initialization

These are the parameters that you can use to set up tracing status at system initialization:

For more details of system initialization parameters, see the CICS® System Definition Guide.

Setting the tracing status using CETR

You can use the CICS/ESA trace control transaction (CETR) to set the tracing status. Figure 23 shows you the CETR screen you can use to set the tracing status dynamically.

Figure 23. Tracing options shown on a CETR screen
CETR                    CICS/ESA Trace Control Facility
Type in your choices.
Item                              Choice       Possible choices
Internal Trace Status       ===>  STOPPED      STArted, STOpped
Internal Trace Table Size   ===>  0016 K       16K - 1048576K
Auxiliary Trace Status      ===>  PAUSED       STArted, STOpped, Paused
Auxiliary Trace Dataset     ===>  B            A, B
Auxiliary Switch Status     ===>  ALL          NO, NExt, All
GTF Trace Status            ===>  STARTED      STArted, STOpped
Master System Trace Flag    ===>  OFF          ON, OFf
Master User Trace Flag      ===>  OFF          ON, OFf
When finished, press ENTER.
PF1=Help      3=Quit      4=Components      5=Ter/Trn     9=Error List

In this example, internal tracing status is STOPPED, and so regular tracing is not directed explicitly to the internal trace table. However, note that the internal trace table is used as a buffer for the other trace destinations, so it always contains the most recent trace entry if at least one trace destination is STARTED. The internal trace table is also used as a destination for exception trace entries, which are made whenever CICS detects an exception condition. If such a condition were detected when the options shown in this example were in effect, you would be able to find the exception trace entry in the internal trace table as well as in the GTF trace data set.

The internal trace table size is 16KB, which is the minimum size it can be. If internal trace were STARTED, the trace table would wrap when it became full.

The current auxiliary trace data set is B, meaning that trace entries would be written to DFHBUXT if auxiliary tracing were started. However, its status is shown to be PAUSED, so no tracing is done to that destination. The auxiliary switch status is ALL, so a switch would be made to the other auxiliary trace data set whenever one became full.

The GTF trace status is shown to be STARTED, which means that CICS trace entries are written to the GTF trace data set defined to MVS. Be aware that no error condition is reported if the CICS GTF status is started but GTF tracing has not been started under MVS. If this happens, the trace entries are not written. The master system trace flag is OFF. This means that no standard tracing is done at all, even though standard tracing might be specified for some tasks. However, special task tracing is not affected--the master system trace flag only determines whether standard task tracing is to be done.

You can see the role of the master system trace flag in Table 26.

The master user trace flag is OFF, so no user trace entries can be made from applications. You must set the master user trace flag on before any user trace requests in your programs can be serviced. If it were off, any trace call requests in your programs would be ignored.

The following logic is used used to ensure that trace entries are written to the required destinations:

  1. The trace entry is built in the internal trace table.
  2. If auxilliary tracing status is STARTED, the trace data is copied to the current auxilliary trace data set.
  3. If GTF tracing status is STARTED and GTF tracing is started under MVS with the TRACE=USR option, the trace data is copied to the GTF trace data set.

Related Concepts
CETR -- trace control
CICS tracing

Related Tasks
Selecting trace destinations and related options
Selecting tracing by transaction
Selecting tracing by component
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