In some Interact environments, a high number of concurrent sessions may cause the
Interact runtime to exceed its available memory, causing a system slowdown or out-of-memory error. An out-of-memory situation is more likely if you have increased the
maxNumberOfSessions configuration parameter (
Interact | sessionManagement | maxNumberOfSessions) to a number higher than the default setting, although it can occur even with the default setting of a maximum of 100,000 sessions. To avoid this issue, you can reduce the
maxNumberOfSessions value, or you can follow the instructions here to modify the system memory cache to roll the cached memory over to disk storage. This modification allows many more concurrent sessions than would otherwise be possible.
To prevent the Interact runtime from exceeding the available memory in the
Java™ virtual machine (JVM) memory heap, you can modify the memory caching mechanism to use disk storage for caching the data that exceeds the available memory.
Interact uses an open source distributed caching system called Ehcache for caching data. By default,
Interact uses the settings specified by the
IBM® Marketing Platform to manage the Ehcache caching. However, you can override those settings for
Interact by creating your own Ehcache configuration file that is automatically loaded whenever
Interact starts up.
If you saved this file as /IBM/Interact/conf/Ehcache.xml, you would then set the JVM property for the web application as in the following example: