QueueDispatcher for Rails3

This Rails3 Gem implements a method to perform long running methods in the background. Background tasks will be executed by persistent workers.

Install

Inside your Gemfile:

gem "queue_dispatcher"

and then run:

bundle install

To install the queue_worker_dispatcher script, which starts all workers, execute the following rake command:

rake queue_dispatcher:sync

Database Setup

Use

rails g queue_dispatcher:migration

This will create a database migration for the models Task and TaskQueues.

Gem Dependencies

Please check if all those requirements are satisfied on your environment.

  • rails >= 3.0.0

  • sys-proctable >= 0.9.1

Inside your application

To enqueue a long running task, simple call a method through enque. E.g.: Assume, you have a long running job:

LongRunningMailJob.send_mail

Now we'd like to execute it in the background by simply calling:

task = LongRunningMailJob.enqueue.send_mail

If you like to put the job in a queue, you can do this by execute it the following way:

task = LongRunningMailJob.enqueue(queue: 'queue_name').send_mail

Jobs inside a queue are executed serialized, not in parallel. You can define dependencies. A task is then executed only after all dependent tasks are finished. The dependencies could also be in another queue. This way you could ensure, that a task is only executed when another task from another queue is successfully finished. Code to add Task dependencies:

task.dependent_tasks = another_task

Queue Worker Dispatcher

The QueueWorkerDispatcher-script starts the workers (default are 10 workers). A worker waits for a new queue and executes all tasks of this queue. Start the QueueWorkerDispatcher by executing the following command:

script/queue_worker_dispatcher

To start the QueueWorkerDispatcher as a daemon, use the option -b.

-b, --background        work in background mode

License

This project is licenced under the MIT license.

Author

Philip Kurmann (philip (at) kman.ch)