You can activate JVM server tracing by turning on SJ and
AP component tracing. Small amounts of trace are written to the internal
trace table, but Java™ also writes
out logging information to a unique file in zFS for each JVM server.
This file does not wrap so you must manage its size in zFS.
About this task
JVM server tracing does not use auxiliary or GTF tracing. CICS® writes some information to
the internal trace table. However, most diagnostic information is
logged by Java and written to
a file in zFS. This file is uniquely named for each JVM server. The
default file name has the format &DATE;.&TIME;.dfhjvmtrc and
is created by CICS in the $WORK_DIR/&APPLID;/&JVMSERVER; directory
when you enable the JVMSERVER resource. You can change the name and
location of the trace file in the JVM profile. If you delete or rename
the trace file when the JVM server is running, CICS does not re-create the file and the logging
information is not written to another file.
Procedure
- Use the CETR transaction to activate tracing for the JVM
server.
You can use two components to produce tracing and
logging information for a JVM server:
- Select the SJ component to trace the actions taken by CICS to start and stop the JVM
server. The JVM logs diagnostic information in the zFS file.
- Select the AP component to trace the installation of OSGi
bundles.
- Set the tracing level for the SJ and AP components:
- SJ level 0 produces tracing for exceptions only, such as errors during the initialization of
the JVM server or problems in the OSGi framework. SJ level 1 and level 2 produce more CICS tracing from the SJ domain. This tracing is written to the
internal trace table.
- SJ level 3 produces additional logging from the JVM, such
as warning and information messages in the OSGi framework. This information
is written to the trace file in zFS.
- SJ level 4, SJ level 5 and AP level 2 produce debug information from
CICS and the JVM, which provides much more detailed
information about the JVM server processing. This information is written to the trace file in
zFS.
- Each trace entry has a date and time stamp. You can change
the name and the location of this trace file by using the JVMTRACE profile
option.
- If you are using the default JVMTRACE settings,
when you enable the JVMSERVER resource CICS creates
a new unique trace file for the life of the JVM.
If you
disable the JVMSERVER resource, you can delete the trace file or rename
the file if you want to retain the information separately.
- To manage the number of files you can set the LOG_FILES_MAX
option to control the number of old trace files that are retained
on the JVM server startup.