How to Use Memcached with Django for Fast Caching

To use memcached with Django, install a Memcached server and a Python client like python-memcached or pylibmc. Then, configure Django's CACHES setting to use the Memcached backend by specifying the server address and backend class.

Syntax

Configure Django's CACHES setting in settings.py to use Memcached. You specify the backend class and the Memcached server location.

• BACKEND: The cache backend class for Memcached.
• LOCATION: The Memcached server address (host:port).

python

CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.PyMemcacheCache',
        'LOCATION': '127.0.0.1:11211',
    }
}

Example

This example shows how to configure Memcached in Django and use the cache API to store and retrieve a value.

python

import django
from django.conf import settings
from django.core.cache import cache

settings.configure(
    CACHES={
        'default': {
            'BACKEND': 'django.core.cache.backends.memcached.PyMemcacheCache',
            'LOCATION': '127.0.0.1:11211',
        }
    },
    INSTALLED_APPS=[],
)
django.setup()

# Store a value in cache
cache.set('greeting', 'Hello Memcached!', timeout=60)

# Retrieve the value
value = cache.get('greeting')
print(value)

Output

Hello Memcached!

Common Pitfalls

Common mistakes when using Memcached with Django include:

• Not running a Memcached server before starting Django.
• Using an incorrect backend string or server address in CACHES.
• Forgetting to install a compatible Python Memcached client like python-memcached or pylibmc.
• Setting very short or zero timeout values, causing cache misses.

python

## Wrong backend example (legacy or incorrect)
CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',  # Deprecated
        'LOCATION': '127.0.0.1:11211',
    }
}

## Correct backend example
CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.PyMemcacheCache',
        'LOCATION': '127.0.0.1:11211',
    }
}

Quick Reference

Summary tips for using Memcached with Django:

• Install and run Memcached server on your machine or server.
• Install a Python Memcached client: pip install python-memcached or pip install pylibmc.
• Set CACHES in settings.py with the correct backend and location.
• Use Django's cache API to set, get, and delete cached data.
• Test caching by storing and retrieving values to confirm setup.

Key Takeaways

Always install and run a Memcached server before configuring Django caching.

Use the modern backend 'django.core.cache.backends.memcached.PyMemcacheCache' for best compatibility.

Install a Python Memcached client like 'python-memcached' or 'pylibmc' to connect Django to Memcached.

Configure the 'CACHES' setting in Django with the correct backend and server location.

Use Django's cache API to store and retrieve data efficiently from Memcached.