Example

Concurrency Processor

Demonstrates how helix-concurrency fire-and-forget processors handle single events and batches asynchronously. Shows a custom FireForgetProcessor, a custom BatchFireForgetProcessor, and the graceful vs immediate shutdown switch.

Group: Library
Path: examples/library/concurrency-processor

Source README

Overview

Helix Java application that shows how helix-concurrency fire-and-forget processors handle single events and batches asynchronously.

Run this example from the shared examples build:


./gradlew -p examples runExample -Pexample=library/concurrency-processor --init-script "$(pwd)/helix.init.gradle"

What It Shows

implementing a custom FireForgetProcessor for one-at-a-time async work
implementing a custom BatchFireForgetProcessor for grouped async work
submitting events without blocking the caller on processing
waiting for processor work to drain in tests and demo code
using the helix.fireforget.immediate-shutdown system property to switch shutdown behavior from graceful to immediate

Example Output

Helix concurrency processor example
fireForget.processed=[invoice-created, invoice-emailed, invoice-archived]
batch.processed=[[audit-1, audit-2], [audit-3]]
shutdown.behavior=GRACEFUL

Development

Building the Application

Run the following command to build the application:


./gradlew clean build

Testing the Application

Run the following command to run the application tests:


./gradlew test
./gradlew integration

Running the Example

Run the application and inspect how the two processor styles consume work:

Force immediate shutdown behavior instead of graceful draining:


./gradlew run


./gradlew -Dhelix.fireforget.immediate-shutdown=true run