The siddhi-execution-approximate is an extension to Siddhi that performs approximate computing on event streams.

Find some useful links below:

• Source code
• Releases
• Issue tracker

Latest API Docs is 1.0.6.

Using the extension in WSO2 Stream Processor

• You can use this extension in the latest WSO2 Stream Processor that is a part of WSO2 Analytics offering, with editor, debugger and simulation support.

• This extension is shipped by default with WSO2 Stream Processor, if you wish to use an alternative version of this extension you can replace the component jar that can be found in the <STREAM_PROCESSOR_HOME>/lib directory.

Using the extension as a java library

• This extension can be added as a maven dependency along with other Siddhi dependencies to your project.

     <dependency>
        <groupId>org.wso2.extension.siddhi.execution.approximate</groupId>
        <artifactId>siddhi-execution-approximate</artifactId>
        <version>x.x.x</version>
     </dependency>

Branch	Build Status
master

• count ((Stream Processor))
  

  This extension applies the Count-min-sketch algorithm to a Siddhi window. The algorithm is set based on a specific relative error and a confidence value to calculate the approximate count(frequency) of events. Note that using this extension without a window may cause out of memory.

• distinctCount ((Stream Processor))
  

  This applies the HyperLogLog algorithm to a Siddhi window. The algorithm is set with a relative error and a confidence value to calculate the number of distinct events with an accepted level of accuracy. Note that if this extension is used without a window, it may cause out of memory errors. If you need to perform these calculations without windows, use the approximate:distinctCountEver extension.

• distinctCountEver ((Stream Processor))
  

  This extension applies the HyperLogLog algorithm set on a specific relative error and a confidence value to a Siddhi window in order toon a streaming data set based on a specific relative error calculate the number of distinct events. Note that this extension returns erroneous values if is is used with a Siddhi window. If you want to perform these calculations with a window, you need to use the approximate:distinctCount extension.

• Please report issues at GitHub Issue Tracker.

• Send your contributions as pull requests to master branch.

• Post your questions with the "Siddhi" tag in Stackoverflow.

• Siddhi developers can be contacted via the mailing lists:

  Developers List : [email protected]

  Architecture List : [email protected]

• We are committed to ensuring support for this extension in production. Our unique approach ensures that all support leverages our open development methodology and is provided by the very same engineers who build the technology.

• For more details and to take advantage of this unique opportunity contact us via http://wso2.com/support/.