Messages from the master JVM that initializes the shared class cache are
written to the HFS file specified by the CLASSCACHE_MSGLOG option in the JVM
profile for the master JVM. The default name for this file is dfhjvmccmsg.log.
To report on the status of the shared class cache, use the
CEMT INQUIRE CLASSCACHE command (or the equivalent EXEC CICS command).
The shared class cache can be in one of four states:
- STARTING
- The shared class cache is being initialized. If autostart is enabled,
the shared class cache is starting either because CICS received a request
to run a Java application in a JVM whose profile requires the use of the shared
class cache, or because an explicit CEMT PERFORM CLASSCACHE START command
(or the equivalent EXEC CICS command) was issued. If autostart is disabled,
the shared class cache is starting because an explicit CEMT PERFORM CLASSCACHE
START command (or the equivalent EXEC CICS command) was issued. If CICS receives
requests during this period for worker JVMs that require the use of the shared
class cache, the requests wait until the startup process is complete and the
shared class cache is ready. If initialization of the shared class cache is
unsuccessful, any waiting requests for worker JVMs fail.
- STARTED
- The shared class cache is ready, and it can be used by worker JVMs.
- RELOADING
- A CEMT PERFORM CLASSCACHE RELOAD command (or the equivalent EXEC CICS
command) has been issued, and a new shared class cache is being loaded to
replace the existing shared class cache. Worker JVMs, both those that were
already allocated to tasks and those that were allocated to tasks after the
command was issued, continue to use the existing shared class cache until
the new shared class cache is ready.
- STOPPED
- The shared class cache has either not been initialized on this CICS
execution, or it has been stopped by a CEMT PERFORM CLASSCACHE PHASEOUT, PURGE
or FORCEPURGE or CEMT SET JVMPOOL PHASEOUT, PURGE or FORCEPURGE command (or
the equivalent EXEC CICS commands). If autostart is disabled, requests to
run a Java application in a JVM whose profile requires the use of the shared
class cache (that is, requests for worker JVMs) will fail. If autostart is
enabled, a new shared class cache will be initialized as soon as CICS receives
a request to run a Java application in a JVM whose profile requires the use
of the shared class cache.
The
CEMT INQUIRE CLASSCACHE command (or the equivalent
EXEC CICS command) also tells you:
- The status of autostart for the shared class cache (AUTOSTARTST).
- The size of the shared class cache (CACHESIZE) and the amount of free
space in it (CACHEFREE).
- The date and time that the current shared class cache was started (STARTTIME
for the EXEC CICS command, or DATESTARTED and TIMESTARTED for the CEMT command).
- The JVM profile for the master JVM that initializes the shared class cache
(PROFILE).
- The level of reusability for the master JVM, which is inherited by all
the worker JVMs in the CICS region (REUSEST).
- Whether there are any old shared class caches in the region that are waiting
for worker JVMs that are dependent on them to be phased out (OLDCACHES). If
the status of the current shared class cache is STOPPED, then it is included
in the number of old shared class caches.
- The number of worker JVMs that are dependent on an old shared class cache,
and are being phased out (PHASINGOUT).
- The total number of worker JVMs in the region that are dependent on a
shared class cache, old or current (TOTALJVMS).
To report on the status of the JVMs in the JVM pool, use the CEMT INQUIRE JVM command (or the equivalent EXEC CICS command). This command
tells you about a specified JVM or about each JVM in the pool, indicating
the task to which it is allocated, whether its execution key is USER or CICS,
and whether or not it is using the shared class cache. The INQUIRE JVM command
does not find the master JVM that initializes the shared class cache. It only
finds worker JVMs and standalone JVMs.