Sample application for job-scheduling.

Following are the key components:

Job Acceptor: a rest endpoint which will accept a job to occur at specified times and repeats. It breaks down the job into events and stores in redis

Job Scanner: a scheduled task that runs and scans redis for scheduled events, and publishes to kafka topic for processing

Job listener: a kafka topic listener that processes events

Redis: is used as job-store.

Kafka: is used for distribution of events for processors.

There are essentially 2 application services that are run.

1. job-acceptor-scanner - accepts job, schedules events, scans for events and pushes to kafka topic

2. messaging - listens to messages on kafka topic and does the needful processing

3. job-models: A simple lib project for the the common models.

Needs JDK 17, Docker

Edit the build.sh file to set JAVA_HOME. (I used jenv, check build.sh file). Also check the docker-compose file for ports and variables. Individual application properties are in respective application.yml file

1. Build

./build.sh

docker compose down

docker compose up -d

docker compose logs --follow

2. create events for jobs as shown below through API. The API will return all events derived from the job definition and an acknowledgement id. The scanner runs every minute and checks for events that need to be processed (offset by a min). Once an event is published on kafka topic, you should be able to see the processor listener logs in the console.

curl --request POST \
  --url http://localhost:8080/api/jobs \
  --header 'Content-Type: application/json' \
  --header 'User-Agent: insomnia/10.0.0' \
  --data '{
	"jobType" : "task-reminders",
	"title": "Remember to pay for wife'\''s mobile",
	"repeat": {
		"eventsAt": ["15-09-2024 23:54", "15-09-2024 23:54", "15-09-2024 23:55", "15-09-2024 23:55", "15-09-2024 23:55"]
	},
	"event": {
		"info": "remember to take medications"
	}
}'