You must prepare CTRACE controls and resources before you can use it for trace
data.
Before you begin
Before you start component trace (CTRACE) activity for WebSphere® Application Server for
z/OS® servers, you
need to decide on some values for CTRACE controls and resources, also create an external writer if
one is needed for trace data recording.
About this task
Complete the following steps to prepare CTRACE controls and resources:
Procedure
- Decide whether to write CTRACE data to trace data sets
(recommended) or keep CTRACE data in memory buffers only.
- If you want to use trace data sets, complete these steps.
- Decide whether to create one trace data set for all WebSphere Application Server activity on a single z/OS system or separate
trace data sets for each cell or WebSphere Application Server release.
Trace data sets cannot be shared between z/OS systems; each system must have its own trace data sets.
- Choose names for the trace data sets.
To simplify external writer setup, include the z/OS system name in the data set name.
Recommendation: For a single trace data set for all WebSphere Application Server
activity, use something similar to SYS1.sysname.WAS390.CTRACE.
- Allocate a trace data set on each z/OS system.
Pratiques recommandées: Do not specify DCB parameters RECFM, LRECL, or BLKSIZE; the external writer allocates them with
record format VB and a system-optimal blocksize and logical record length. For trace data sets on
disk, you must use a minimum of 10 cylinders (3390). Secondary extents are ignored unless the NOWRAP
option is specified when the external writer is started. For example:
bprac
// EXEC PGM=IEFBR14
//TRACE DD DSN=SYS1.MVSS14.WAS390.CTRACE,UNIT=3390,VOL=SER=HPK19A,
// SPACE=(CYL,(20,0)),DISP=(NEW,CATLG),DCB=DSORG=PS
- Choose a job name for the external writer.
Recommendation: Use BBOWTR if the same trace data set is used for all WebSphere Application Server
activity on each z/OS
system.
- Create the external writer cataloged procedure.
- Copy member BBOWTR from the WebSphere Application Server for z/OS product directory
/util/zos/JCL/ to SYS1.PROCLIB or another procedure library that is defined to
the master scheduler.
- Rename the procedure to the external writer job name that you chose.
- Customize the cataloged procedure by providing your trace data set name where indicated.
- If the cataloged procedure is shared among several z/OS systems, make sure that the trace data set DD statements
point to the appropriate trace data sets on each system.
- Choose a system user ID for the external writer to run under.
This user ID must have read/write access to the trace data sets; you might want to use an
existing started task user ID such as the default started task user ID for your system. Use the
following RACF®
command or equivalent to cause the external writer cataloged procedure to run under the started task
user
ID:
RDEFINE STARTED external_writer_procname.* STDATA(USER(system_user_ID)) TRACE(YES)
The external writer started task should run with at least as high a dispatching priority as the WebSphere
Application Server address spaces that use it for tracing.
- Start the external writer to verify that the previous steps were completed correctly.
Enter the following MVS™ console
command:
TRACE CT,WTRSTART=external_writer_procname
- Create a CTRACE parmlib member.
- Copy member BBOCTI00 from the WebSphere Application Server for z/OS product directory
/util/zos/JCL/ to a data set in your system parmlib concatenation.
- Rename the parmlib member to CTIBBOxx,
where xx is a two-character suffix to be associated
with the external writer.
This value is specified during WebSphere Application Server for z/OS customization.
- Customize the CTIBBOxx parmlib member to indicate whether trace data sets
and an external writer are to be used. If so, whether the external writer is started automatically
when WebSphere
Application Server activates the CTRACE.
- If you plan to use separate trace data sets for different WebSphere Application Server cells
or releases, repeat all of these steps but choose a new external writer name and parmlib member
suffix for each.
Results
CTRACE for WebSphere Application Server is now set up. Use the parmlib member suffix to associate a
particular WebSphere Application Server for z/OS cell with the CTRACE options that you chose.