Configuring JVM settings for the integration server
The default settings of the Java™ Virtual
Machine (JVM) are sufficient for most situations. However, as your
requirements on message flow logic
or nodes grows, the settings must be adjusted to ensure continued
levels of service.
For
IBM® Integration Bus,
the default memory settings of the JVM are as follows:
- Minimum: 32 MB
- Maximum: 256 MB
The amount of Java heap
that is required depends on the
message flows, and
in particular the amount of Java that
they contain. Remember, some message flow nodes such as the
FileInput node,
or the
SAPInput node
are written in Java. Therefore,
different
integration
servers might
require different Java heap
settings, so the same values cannot be reused for every
integration server.
A larger Java heap might
be needed when there is a heavy requirement from the
message flow logic,
or from the message flow nodes that are used within it. The best way
to determine whether there is sufficient Java heap
is to look at the resource statistics for the
integration server to
check the level of garbage collection.
- For batch processing, low garbage collection resource statistics
is the target. A garbage collection resource statistic of 1% is ideal.
- For real-time processing, low pause times are the target. A low
pause time of under 1 second is ideal.
For guidance on resource statistics, see
Starting resource statistics collection in
the online product documentation.
The
IBM Integration Bus JVM
heap settings can be changed with the
mqsichangeproperties command.
The following example increases the maximum JVM heap to 512 MB for
the
integration server
IN_OUT, in the
integration node
PERFBRKR:
mqsichangeproperties PERFBRKR -o ComIbmJVMManager -e IN_OUT -n jvmMaxHeapSize -v 536870912