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
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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.
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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 produces 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, 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.
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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.
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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.