Esper Extension Library
Esper is an OSS Complex Event Processing (CEP) library which enables anyone to build high-throughput, low-latency, real-time event processing applications.
The Esper extension library is a set of utility plugins you can use in your Esper implementation.
At version 0.1.0 it is stable although it still does not have many extensions. Currently it mostly has a plugin view that calculates the TRIX index over a value in an event stream. This index allows you, in fact, to calculate the tendency of that value - is it trending up, down, stable?
There are plans to include further extensions for things like:
- Named window persistance and recovery after restarting
- Catalog of technical analysis plugin windows and aggregation functions (great for Algorithmic Trading but also for general time series trend analysis)
- EPL rule annotations
- (many more...)
Suggestions and contributions are welcome :-)
Getting Started
You can build your own JAR or download a prebuilt one. You include the JAR in your classpath and configure the plugin windows and functions in your esper configuration files. For more information go here.
Building JAR:
Build scripts are just plain-old Ant. To generate a JAR just do:
ant dist
Maven:
This project still hasn't been Mavenified but I plan to do it as soon as I have some time. For the time being, if you are using Maven just include the following in your pom.xml:
<dependency>
<groupId>frogfish</groupId>
<artifactId>esper-ext</artifactId>
<version>0.1.0</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/esper-ext-0.1.0.jar</systemPath>
</dependency>
License
esper-ext is open source software released under the MIT License (see LICENSE file). I will be happy to integrate patches from anyone willing to contribute.