Description

RabbitMQ based cron events emitter service. It is not supposed to be scalable, so you need to run only one auto-restart replica. Well-suited for small and medium-sized apps.

How it works

1. Build & Run
2. Fork it by creation of any queue
3. Bind the queue to scheduler exchange with a predefined routing key (e.g. minute or second)

Sample new-items-poll-tick-queue configuration:

rabbitmqadmin declare queue name=new-items-poll-tick-queue durable=false
rabbitmqadmin declare binding source=scheduler destination_type=queue destination=new-items-poll-tick-queue routing_key=minute

An example message to be emitted:

Exchange 	scheduler
Routing Key 	minute
...
headers:	
content_encoding:	UTF-8
content_type:	application/json
...
Payload
Encoding: string

{"timestamp":"2024-09-24 10:00:00"}

Get started

Build requirements:

• latest JDK and Maven

Runtime stack:

• Java 20
• RabbitMQ 4

Checkout the project and build it using mvn package command

An example run:

java -jar -Xmx256M target/rabbitmq-cron.jar \
    --server.port=8000 \
    --spring.rabbitmq.host=rabbitmq \
    --spring.rabbitmq.port=5671 \
    --spring.rabbitmq.username=guest \
    --spring.rabbitmq.password=guest

Warning

Ensure that this service is initially started before other dependent services, as it creates durable scheduler exchange

Also available on Docker Hub