This directory contains implementations of Heron bolts that can be used in user topologies.

The bolt implementations are maintained by Heron community.

Bolt Development

• https://apache.github.io/incubator-heron/docs/developers/python/bolts/
• https://apache.github.io/incubator-heron/docs/developers/java/bolts/

Requirements

Directories and Files

Bolt implementation files should be organized in this directory structure:

external/bolts/{bolt_name}/{language}

Language: java, python, scala, etc bolt name: reduce_bolt, filter_bolt, etc

Files in each bolt should be organized into these subdirectories:

• src/main/: source code
• src/test/: unit tests
• doc/ : documentations

Documentation

Each bolt should have a design doc as well as related information in the doc/ directory.

License

All source code files should include a short Apache license header at the top.