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The Event Distribution Pattern


The Event Distribution Pattern provides a simple mechanism distribute application defined Events via one or more Event Channels. Specifically the Event Distribution Pattern allows the definition, construction and use of Event Distributors, that of which have the responsibility of guaranteeing in-order asynchronous delivery of Events via the defined Event Channels.

There are several Event Distributor implementations, each based on different internal technologies to provide Event delivery guarantees. Levels of performance, scalability and quality of service may differ between implementations. As of writing, there are two out-of-the-box Event Distributor implementations; one based on Oracle Coherence itself (using the Messaging Pattern, another that leverages the Java Messaging Service (JMS) providers.

Like Event Distributors, there are many Event Channels each of which provides different capabilities and ultimate destinations for events being distributed.
Ultimately it's the responsibility of an Event Channel to perform the actual distribution of Events. Commonly used Event Channel implementations include:

  • FileEventChannel - Writes Events to a File.

  • LocalCacheEventChannel - Replays Events into a Cache hosted by the Cluster in which the Events occurred.

  • RemoteCacheEventChannel - Replays Events into a Remote Cache defined by a Oracle Coherence *Extend connection to a remote Cluster.

  • RemoteClusterEventChannel - Distributes Events to another Oracle Coherence Cluster, again over an *Extend connection (where by said Events may be further distributed locally).

  • StdErrEventChannel - Writes Events to stdout.

Ultimately the purpose of this pattern is to provide an extensible, high-performance, highly-available, general purpose scalable framework to distribute application events occurring in one Coherence Cluster to one or more possibly distributed Coherence Clusters, Caches or other Devices. As such, the Event Distribution Pattern is used as core infrastructure for the Push Replication Pattern.


The Event Distribution Pattern implementation is distributed in the jar file called: coherence-eventdistributionpattern-12.1.0.jar.

However as the Event Distribution Pattern has several other dependencies, we **strongly recommend** that developers adopt and use tools like Apache Maven/Ivy/Gradle to transitively resolve the said dependencies, instead of attempting to do so manually.

To configure your Apache Maven-based application to use the Event Distribution Pattern, simply add the following declaration to your application pom.xml file <dependencies> element.