Try OpenEdge Now
skip to main content
BP Server Developer's Guide
JMS based event publisher : Event channels : Event channel cache

Event channel cache

For each event sent to each sender class, all event channels are accessed and the event is published only to the qualified channels. Filter conditions of each channel are evaluated using the given event object and the event is published to this channel only when the filter conditions are evaluated to true.
The channel information is cached for faster reference. The cache is created for the first time when the Event Publisher is started. Event Channel cache is refreshed whenever a new channel is added, or when a client utility is invoked to send the REFRESH message. When the cache is refreshed, Event Publisher maintains consistency by ensuring that the sender class is not using the cache.
The cache is maintained as a collection of value objects. During the start and refresh method invocation, all the channels are validated for expiration date, and the expired channels are removed from cache and database.