Use Redis with Django Rest Framework

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What is considered slow depends on your requirements. But when something becomes slow it's a candidate for caching.High Scalability

We already know enough about Redis, Django & Django Rest Framework to use them.

Here is a video link to describe Redis in 100 seconds in case you don't know about it.

  1. First we will install a Redis server to use Redis locally.
  2. Then we run the server and learn some basic commands for Redis CLI.
  3. We will integrate Redis with Django Rest Framework.

First

I'm using Debian therefore I'm going to install Redis via apt

sudo apt install redis

You can install Redis via .tar file and can use Docker. The instructions are here.

Second

After installation finish, we can use redis-server in the terminal to start the local server and to access the server via CLI we run redis-cli in a different terminal.

Basic Redis commands are: SET [key] [value] to set the string value to a key.

SET name Sagar
OK

GET [key] to get the value of a key.

GET name
"Sagar"

KEYS * to display the list of all stored keys.

KEYS *
1) "name"

FLUSHDB to remove all keys from the current database.

FLUSHALL to remove all keys from all the databases.

More commands can be found here.

Third

Install these required packages

pip install django djangorestframework django-redis

Start the Django project via django-admin startproject test_project & open your text editor into that folder. I use Visual Studio Codium so for me codium test_project.

Inside settings.py:-

INSTALLED_APPS = [
    ....
    'rest_framework',
]

CACHES = {
    "default": {
        "BACKEND": "django_redis.cache.RedisCache",
        "LOCATION": "redis://127.0.0.1:6379/1", # Local Link provided by the redis-server command
        "OPTIONS": {
            "CLIENT_CLASS": "django_redis.client.DefaultClient",
        }
    }
}

Explanation: rest_framework to use rest framework package and CACHES to connect Redis with Django same as we use to connect databases with Django.

Inside views.py:-

from rest_framework.response import Response
from rest_framework.views import APIView
from django.core.cache import cache
from django.conf import settings
from django.core.cache.backends.base import DEFAULT_TIMEOUT

# For cache timeout
CACHE_TTL = getattr(settings, 'CACHE_TTL', DEFAULT_TIMEOUT)

class TestView(APIView):
    def get(self, request):

        # Locate name in redis database
        if 'name' in cache:
            # get results from cache
            name = cache.get('name')

            print('form cache')
            return Response(name)

        # If not found 
        else:
            result = {
                "name": "Sagar Yadav"
            }

            # store data in cache
            cache.set('name', result, timeout=CACHE_TTL)

            print('not from cache')
            return Response(result)

Lastly specify the url inside urls.py:-

urlpatterns = [
    path('', TestView.as_view(), name='test-url'),
]

Now run the python server via python3 manage.py runserver and don't forget to start the redis via redis-server.

Visit localhost:8000 in your browser and refresh the page twice where the response will always be the same each time, then check your python terminal. The terminal would look like this.

not from cache
[datetime] "GET / HTTP/1.1" 200 5110
form cache
[datetime] "GET / HTTP/1.1" 200 5110
form cache
[datetime] "GET / HTTP/1.1" 200 5110

Now, you know how you can use Redis with Django Rest Framework. You just have to think about what data you need to cache. You can store serialized data into a cache with a unique key to look upon and much more.

Thanks for reading.