Changing the Value of -Xmx

The -Xmx option is one of the JVM settings you might need to change.

What it does

The -Xmx option limits the maximum size of the Java heap. This is a continuous memory region where all Objects data—instances of class, primitives, and references—is stored. It forms a large part of the process heap. Properly tuning this parameter can reduce the overhead of garbage collection; if it is set too low, the result can be a large number of minor garbage collections. This reduces server response time and throughput.

Original value

When you initially configure ActiveMatrix BPM you can select one of the following default values for -Xmx using the Maximum Java Heap Size field in TIBCO Configuration Tool - see TIBCO Configuration Tool (TCT).

For development systems: 1024 mb.

For production systems: 4096 mb.

Monitoring

Regular monitoring of your JVM is necessary to show whether or not you need to change the value of this option. If the heap memory is being used up, try increasing the value of -Xmx. This may (depending on the setting of the -Xss Thread Stack Size option) enable more threads or connections to be created. However, do not use a value so large that it would cause swapping or impact garbage collection performance , as this would then drastically reduce the performance of BPM system.