When a NERV emit application sends events, the events first go through Ehcache, where they can be persisted temporarily. After that, the events are sent to an internal channel, where they are processed and sent asynchronously to the Event Bus. To ensure that no events are lost before reaching the Event Bus, NERV enables you to use Ehcache by setting a level of guaranteed delivery for your events. After an event is successfully delivered to the event bus, it is deleted from the cache.

By default, NERV reads the Ehcache persistence configuration settings from the Software AG_directory \common\conf\nerv\cache directory. It contains preconfigured MAXIMUM_STRONG.xml and MAXIMUM_EVENTUAL.xml files with settings used by Ehcache to guarantee the delivery of events. For more information about the available settings and their values, see Ehcache product documentation for 2.8 at http://ehcache.org/documentation.

You can modify the Ehcache configuration settings location that NERV uses by modifying the value of the Cache Configuration Location configuration property for your NERV installation node using the Command Central user interface. For more information about the Cache Configuration Location property, see NERV Configuration Properties.