README.md

Djangotasks

Django-tasks is an asynchronous task management daemon, to execute long-running batch tasks (minutes, hours or even days) for Django applications.

The following repo is the clone of original repo at Google Code.

Current version is formed from revision r51 of original SVN repo.

About

Django-tasks is for a different usage from most other tasks frameworks (Celery, Cue, etc.): this is not for numerous, quick, light, tasks, but for few, long, heavy, tasks. Typical usage is to batch process data for each model object, and give information about the processing to the user.

Also, no other software or library is needed. Django-tasks simply uses the Django database as a queue (and Tasks are a simple model); and each task is spawned as its own process.

Main features

Features include:

• Log gathering: at anytime, you can access the standard output created by your tasks,
• Start time, end time... of course
• Task dependency: only run a task of some other dependent task(s) have run (useful when multiple tasks require that one long processing has already happened),
• History (archive) of tasks already run on an object. This is helpful if there are errors or problem, to keep a log of what has run in the past,
• Basic admin view that lets you see what has been, or is, running,
• Cancel running tasks (kills the process).

This is now (August 2010) used in production for a hosted website, and a distributed product, so you should see fixes and improvements over time. Feedback is welcome.

It is tested on Linux and MacOS, and it should run on Windows (per issue 16); and on PostgreSQL and SQLite (with some caveats for SQLite, see below)

Basic usage

To use django-tasks follow instructions.

1. Install djangotasks with pip: pip install git+git://github.com/vladignatyev/django-tasks.git

2. Add djangotasks Django application: INSTALLED_APPS += ('djangotasks',) And build database scheme for the application using: python manage.py syncdb and then python manage.py migrate djangotasks

3. Write your long-running jobs' code.

   Create method for any of your models:

   class MyModel(models.Model):
       # ...
       def long_task(self):
           sleep(5)
   

   Right here in models.py register the task:

   import djangotasks
   djangotasks.register_task(MyModel.long_task, "My first long running task")
   

   Run your tasks from Django View or Django Admin Action using the following code. In views.py:

   import djangotasks
   
   def test_view(request):
       task = djangotasks.task_for_object(my_model_object.long_task)
       djangotasks.run_task(task)
       return HttpResponse(task.id)
   

   Or in admin.py:

   def run_my_model_longtask(modeladmin, request, queryset):
       for my_model_object in queryset:
           task = djangotasks.task_for_object(my_model_object.long_task)
           djangotasks.run_task(task)
   
   run_my_model_longtask.short_description = "My first long running task admin action"
   
   
   class MyModelAdmin(ModelAdmin):
       actions = [run_my_model_longtask,]
   
   site.register(MyModel, MyModelAdmin)
   

4. Run worker with python manage.py taskd start It can run either as a thread in your process (provided you only run one server process) or as a separate process. To run it in-process (as a thread), just set DJANGOTASK_DAEMON_THREAD = True in your settings.py. Note: avoid using as thread configuration in production.

Now you can view the status of your task in the 'Djangotasks' Admin module.

You can of course use the Task model in your own models and views, to provide specific user interface for your own tasks, or poll the status of the task.