How are Django channels different than celery?

Question

Recently I came to know about Django channels. Can somebody tell me the difference between channels and celery, as well as where to use celery and channels.

Answer 1

Channels in Django are meant for asynchronous handling of requests.
The standard model Django uses is Request-Response but that has significant limitations. We cannot do anything outside the restrictions of that model.
Channels came about to allow Web Socket support and building complex applications around Web Sockets, so that we can send multiple messages, manage sessions, etc.

Celery is a completely different thing, it is an asynchronous task queue/job queue based on distributed message passing. It is primarily for queuing tasks and scheduling them to run at specific intervals.

Simply put Channels are used when you need asynchronous data communication like a chat application, and Celery is for scheduling tasks and events like a server scraping the web for a certain type of news at fixed intervals.

Answer 2

• Channels in Django is for WebSocket, long-poll HTTP.

• Celery is for background task, queue.

Answer 3

Django Channels:

beyond HTTP - to handle WebSockets, chat protocols, IoT protocols, and more.

1. Passes messages between client and server (Full duplex connection)

2. Handle HTTP and Web-sockets requests

3. Asynchronous

Example :

• Real time chat application
• Update social feeds
• Multiplayer game
• Sending Notifications

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Celery :

It’s a task queue with focus on real-time processing, while also supporting task scheduling.

1. Perform long running background tasks

2. Perform periodic tasks

3. Asynchronous

Example :

• Processing Videos/images
• Sending bulk emails

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Further reading

Example of Celery and Django Channels

Asynchronous vs Synchronous

Answer 4

Channels is a project that takes Django and extends its abilities beyond HTTP - to handle Web-sockets, chat protocols, IoT protocols, and more. It’s built on a Python specification called ASGI.

Channels changes Django to weave asynchronous code underneath and through Django’s synchronous core, allowing Django projects to handle not only HTTP, but protocols that require long-running connections too - WebSockets, MQTT, chatbots, amateur radio, and more.

It does this while preserving Django’s synchronous and easy-to-use nature, allowing you to choose how you write your code - synchronous in a style like Django views, fully asynchronous, or a mixture of both. On top of this, it provides integrations with Django’s auth system, session system, and more, making it easier than ever to extend your HTTP-only project to other protocols.

It also bundles this event-driven architecture with channel layers, a system that allows you to easily communicate between processes, and separate your project into different processes.

Celery is an asynchronous task queue based on distributed message passing. It provides functionalities to run real-time operations and schedule some tasks to be executed later. These tasks can be executed asynchronous or synchronous, this means you may prefer to run them at the background or chain them to make one task to be fulfilled after the successful execution of an another task.