Tasks

Description

This is a very simple asynchronous task runner. It exposes two HTTP endpoints:

GET /api/jobs 
Returns a list of jobs present in the system

curl -X GET --location "http://localhost:4000/api/jobs" 
 
POST /api/jobs
Create a new job

curl -X POST --location "http://localhost:4000/api/jobs" \
    -H "Content-Type: application/json" \
    -d '{
          "job": {
            "queue_id": "fibonacci",
            "payload": {"n": 303}
          }
        }'   

Once submitted, jobs are saved in a Sqlite3 database. Queues are defined as simple Elixir modules with a perform/1 function which returns a tuple of {:ok, result} or {:error, description}. Eg:

defmodule Tasks.Queues.SleepyQueue do
  def perform(%{"duration" => duration}), do: {:ok, Process.sleep(duration)}
  def perform(_), do: {:error, :invalid_payload}
end

In order to enable the new queue, add it to lib/tasks/queues.ex eg:

@queues [
    %{id: "fibonacci", module: Tasks.Queues.FibonacciQueue, interval: 1000, workers: 3},
    %{id: "sleeper", module: Tasks.Queues.SleepyQueue, interval: 1000, workers: 3}
  ]

Each queue will spawn the specified number of workers, which will query the database for available jobs at the specified interval. When a worker picks up a job, it creates a lease, so as to prevent the same job from being picked up by multiple workers. Since each worker only picks up one job at a time, the worker count effectively controls the maximum concurrency limit for each queue.

Running The Server

To start your Phoenix server:

• Run mix setup to install and setup dependencies
• Start Phoenix endpoint with mix phx.server or inside IEx with iex -S mix phx.server

Now you can visit localhost:4000 from your browser.

Ready to run in production? Please check our deployment guides.

Extension Possibilities

1. Automated Testing: This submission is sadly lacking in automated tests. Resolving this should be a top priority
2. Documentation: The key modules and functions should be documented
3. Monitoring: The project doesn't implement any monitoring beyond the standard Phoenix functionality

Learn more

• Official website: https://www.phoenixframework.org/
• Guides: https://hexdocs.pm/phoenix/overview.html
• Docs: https://hexdocs.pm/phoenix
• Forum: https://elixirforum.com/c/phoenix-forum
• Source: https://github.com/phoenixframework/phoenix