Automatic purging of individual events
If the JMS engine is enabled on a channel which uses Shared or Serial subscribers, then automatic purging of individual events that have no more subscriber interest will occur when certain conditions are met.
The frequency of the automatic purges is determined by the realm configuration property JMSEngineAutoPurgeTime.
To determine whether or not the JMS Engine can purge individual events from a channel, the following rules apply:
If only Shared and/or Serial durable subscriptions are used on the channel, then all the durables of the channel will be scanned and all common events which are already processed will be purged.
If there are no Shared or Serial durable subscriptions, then a purge of individual events cannot be done. In this case, the JMS purge engine will delete events up to the oldest event ID for which the channel has interest.
If there is a mix of Shared/Serial durable subscriptions and other subscriptions on the channel, then a purge of individual events will be performed only for the events for which Shared or Serial durable consumers don't have interest and whose event ID is lower than the lowest event ID of the non-Shared/Serial durable consumers.
Note:
You can deactivate the JMS engine's functionality for the automatic purge of individual events by setting the value of the system property com.softwareag.um.server.store.JMSEngineIndividualPurgeEnabled to "false". By default, the value of this property is "true".