CICS® performs
many of the tasks needed to manage the JVMs in your JVM pool, including creating
new JVMs, reusing free JVMs, and clearing up unrequired JVMs.
How CICS creates JVMs,
How CICS manages JVMs in the JVM pool and
How CICS allocates JVMs to applications explain
how CICS performs these tasks. You can:
- Select an
appropriate MAXJVMTCBS limit for your JVM pool, to prevent MVS storage constraints. How CICS manages JVMs in the JVM pool explains the issues associated with MAXJVMTCBS,
and what happens when an MVS storage constraint occurs. The CICS Performance Guide tells
you how to work out an appropriate setting for the MAXJVMTCBS system initialization
parameter.
- Monitor your JVM pool, the JVMs in it, and the JVM profiles that they
use, and collect statistics about JVMs and JVM profiles. See Monitoring JVM activity.
- Terminate all the JVMs in the JVM pool, or disable the JVM pool so that
it cannot service new requests. See Terminating or disabling the JVM pool.
- Redirect messages from JVM internals and output from Java™ applications
running in a JVM, and add time stamps and headers to the records. You can
create a merged log file containing the output from multiple JVMs, or a file
containing the output for a single program instance or task. See Redirecting JVM output.
- Control JVM tracing. See Controlling tracing for JVMs.
- Tune the JVM pool as a whole, and your individual JVMs, to achieve optimum
performance. The CICS Performance
Guide tells you how to do this.