I was reading John D’Emic’s brilliant post Twitter Complex Event Processing (CEP) with Esper and Drools and got truly inspired. After playing around with the combination of Mule and Esper I was amazed how good they suit each other. Letting Mule do the hard work of shuffling data and intelligent routing while Esper analyzing events on a overall level. It gave me kind of a opportunity to be stateful in a stateless environment. For those who aren’t familiar with Esper, it is what is called a Complex Event Processing engine that allows you to create queries and assertions on streams of events in real-time.
Complex event processing engines are a natural fit for event driven platforms like Mule. Native CEP support has been available in Mule since version 3.2 by way of the Drools Module. The Esper Module now offers an alternate way to leverage CEP in your integration applications. Esper is a robust, performant, open source, complex event processing engine. Let’s take a look at how to use Esper with Mule and then see how it compares to Drools’ CEP support.