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 :-)
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.
Build scripts are just plain-old Ant. To generate a JAR just do:
ant dist
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>
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.