Stand-alone Heron Streamlet Examples

This is a collection of stand-alone Heron examples that are based on samples from various sources. These sources include:

• The Streamlet examples within the official Heron Github repository
• The Streamlio wordcount example
• The snippits of code within the Heron online documentation:
  • The Heron Streamlet API for Java
  • The Heron Streamlet API

These were created during work to implement acking for Streamlet ATLEAST_ONCE topologies.

They are meant to be run against a modified version of the 0.20.x line of Heron. This modified version is the streamlet-acks branch of my Heron fork and can be cloned or downloaded at this link.

Note that this is still a work in progress. Suggestions and/or corrections are welcome.

To run these Streamlet topologies, the following steps can be followed:

• Clone or download both repos:

  • https://github.com/jmark99/heron-examples (master branch)
  • https://github.com/jmark99/incubator-heron (streamlet-acking branch)

• cd into incubator-heron directory

• Build and install heron locally and add necessary jars to local maven repository. Note, I use Ubuntu.

  • bazel build --config=ubuntu heron/...
  • bazel build --config=ubuntu scripts/packages:binpkgs
  • bazel-bin/scripts/packages/heron-install.sh --user
  • mvn install:install -Dfile=<PATH_TO_HERON_DIR>/bazel-bin/heron/api/src/java/api-shaded.jar -DgroupId=local.heron -DartifactId=heron-api -Dversion=0.20.0 -Dpackaging=jar
  • mvn install:install-file -Dfile=<PATH_TO_HERON_DIR>/bazel-bin/heron/simulator/src/java/simulator-shaded.jar -DgroupId=local.heron -DartifactId=heron-api -Dversion=0.20.0 -Dpackaging=jar
  • mvn install:install-file -Dfile=<PATH_TO_HERON_DIR>/bazel-bin/heron/api/src/java/api-unshaded.jar -DgroupId=local.heron -DartifactId=heron-api -Dversion=0.20.0 -Dpackaging=jar

Once complete:

• cd into the directory containing the heron-examples
• mvn clean assembly:assembly (Note the POM needs to be cleaned up, but I haven't bothered to do so yet.)

Note that you can set various parameters for the examples by modifying the config.properties in the conf directory of the heron-examples project.

At this point you should be able to run the example code using the local cluster.

• heron submit local target/heron-examples-1.0-SNAPSHOT-jar-with-dependencies.jar com.jmo.streamlets.<CLASSNAME> <TOPOLOGY_NAME> --deploy-deactivated
• heron activate local <TOPOLOGY_NAME>

Allow to run as long as you like.

• heron deactivate local <TOPOLOGY_NAME>
• heron kill local <TOPOLOGY_NAME>