First thoughts on Event Processing In Action

I’m in the process of reading the preview version of a new book to be published by Manning: Event Processing In Action by Opher Etzion and Peter Niblett. I agreed to read the book and post a review, and my intention is to post several small reviews as I read through it.

One of the authors (Opher) maintains a blog called Event Processing Thinking, which has many posts about the book and a lot of good content as well.

I am particularly interested in this book because my first impression of Event Processing (as described by Opher on his blog), was that it may not be particularly useful. He began his blog in the same way that he begins the book, with very simple ideas. I would sometimes read his early blog posts and think that he is providing information that is so basic that it may not be worth writing about.  At that time, I also did not see his ideas fitting together into something usable or helpful.

Over time, though, I kept reading his blog. And now I see that not only do the ideas fit together, but that they are quite obviously useful. I’m surprised, in fact, that no one has put this stuff forward before. I don’t know exactly when I had the ah-ha moment about Event Processing, but I’m excited to read the book.

Event Processing In Action (EPIA for short) is about software that processes events, and will be familiar territory to those who have dealt with Event Driven Architecture. Most technical books about this topic cover how to process events. They are about algorithms, coding, software concepts like pub/sub and queue, or hardware architecture to use when processing events.

EPIA adds another dimension to events: the logic that they pass through. Not algorithms, but vocabulary and patterns that can be used to specify and discuss the logic that events flow through. This book is about what happens when processing events, not how it happens.

It seems only natural to separate the specification of event processing logic from the implementation. This book is about specifying the logic, and leaves the implementation details to other books. In retrospect this seems like an obvious idea, but I’ve not seen any other book filling this need. I might put EPIA in a category closer to books on the Unified Modelling Language than to books on programming or systems architecture.