For items where cache-mode=distributedJMS”, the GSAInvalidatorService is used to send cache invalidation events via JMS. To do this, the service sends a JMS event of class atg.adapter.gsa.invalidator.MultiTypeInvalidationMessage, which invalidates a set of items or item types for a given repository. When a transaction is committed, this event is used to invalidate the caches of all items modified in the transaction that use the distributedJMS cache mode.

Because transactions can be arbitrarily large, it is necessary to specify the maximum size of a MultiTypeInvalidationMessage event. The GSAInvalidatorService component includes a property called maxItemsPerEvent, which specifies the maximum number of repository items that one MultiTypeInvalidationMessage can invalidate . The default value for this property is 200. If the number of items to invalidate after a transaction exceeds this threshold, the message invalidates the caches of the updated item types, rather than invalidating caches of individual items. This mechanism keeps the message from growing too large, because it needs only contain information about the item types to invalidate, rather than a list of individual items.

There is no command-line interface for sending MultiTypeInvalidationMessage events. These events are used only for Distributed JMS Caching.