Mark Richards

relay races, once a runner hands off the baton, she is done with the race. This is also true with the broker topology: once an event processor hands off the event, it is no longer involved with the processing of that specific event

The broker topology tends to be easier to deploy than the mediator topology, primarily because the event mediator component is somewhat tightly coupled to the event processors: a change in an event processor component might also require a change in the event mediator, requiring both to be deployed for any given change

Since event-processor components are single-purpose and completely decoupled from other event processor components, changes are generally isolated to one or a few event processors and can be made quickly without impacting other components