ModelQueue: Task Queue Based on Django Models

ModelQueue is an Apache2 licensed task queue based on Django models.

For example, in appname/models.py:

import modelqueue
from django.db import models

class Task(models.Model):
    data = models.TextField()
    status = modelqueue.StatusField(
        db_index=True,
        # ^-- Index for faster queries.
        default=modelqueue.Status.waiting,
        # ^-- Waiting state is ready to run.
    )

And in appname/management/commands/process_tasks.py:

import modelqueue, time
from django.core.management.base import BaseCommand
from .models import Task

class Command(BaseCommand):

    def handle(self, *args, **options):
        while True:
            task = modelqueue.run(
                Task.objects.all(),
                # ^-- Queryset of models to process.
                'status',
                # ^-- Field name for model queue.
                self.process,
                # ^-- Callable to process model.
            )
            if task is None:
                time.sleep(0.1)
                # ^-- Bring your own parallelism/concurrency.

    def process(self, report):
        pass  # Process task models.

And in appname/admin.py:

class TaskAdmin(admin.TaskAdmin):
    list_filter = [
        modelqueue.admin_list_filter('status'),
        # ^-- Filter tasks in admin by queue state.
    ]

ModelQueue is a hazardous project. It takes a bad idea and makes it easy and effective. You may come to regret using your database as a task queue but it won’t be today!

Testimonials

“I didn’t design relational database systems for this.” ~ Edgar Codd

“Well, at least you’re using transactions.” ~ Jim Gray

“You have successfully ignored most of what’s important in queueing theory.” ~ Agner Erlang

Does your company or website use ModelQueue? Send us a message and let us know.

Features

  • Pure-Python
  • Fully documented
  • Performance matters
  • 100% test coverage
  • Hours of stress testing
  • Developed on Python 3.6
  • Tested on Django 1.11
  • Tested on CPython 2.7, 3.4, 3.5, 3.6, PyPy and PyPy3
  • Tested on Linux, Mac OS X, and Windows
  • Tested using Travis CI and AppVeyor CI
https://api.travis-ci.org/grantjenks/django-modelqueue.svg?branch=master https://ci.appveyor.com/api/projects/status/github/grantjenks/django-modelqueue?branch=master&svg=true

Quickstart

Installing ModelQueue is simple with pip:

$ python -m pip install modelqueue

You can access documentation in the interpreter with Python’s built-in help function:

>>> import modelqueue
>>> help(modelqueue)

User Guide

For those wanting more details, this part of the documentation describes introduction, benchmarks, development, and API.

ModelQueue License

Copyright 2018 Grant Jenks

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.