Note: This post applies only to 2.x versions of the Axon Framework, as the implementation of the event processing aspects of the Axon changes significantly with the version 3 release.
If you are not familiar with CQRS and/or the Axon Framework, then consider starting off by reading Exploring CQRS Architecture with Axon Framework, which is a series of post that explores the CQRS architecture/pattern and how the Axon Framework can be used to build applications according to the stipulations of CQRS.
If you’ve read these series of posts, or you are already familiar with CQRS/Axon Framework, then feel free to continue with the rest of this post.