redis ยท diff
v1.0.0 to v1.0.0
92 added, 0 removed. Audit A to A.
---
name: redis
description: "Redis - in-memory database, caching, pub/sub, sessions, rate limiting, data structures"
metadata:
author: OSS AI Skills
version: 1.0.0
tags:
- redis
- database
- caching
- pub-sub
- sessions
- rate-limiting
- data-structures
- nosql
---
# Redis
Redis - in-memory data structure store, used as database, cache, and message broker.
## Installation
```bash
pip install django-redis
```
```python
# settings.py
CACHES = {
'default': {
'BACKEND': 'django_redis.cache.RedisCache',
'LOCATION': 'redis://127.0.0.1:6379/1',
'OPTIONS': {
'CLIENT_CLASS': 'django_redis.client.DefaultClient',
}
}
}
```
---
## Caching
### Basic Configuration
```python
# settings.py
CACHES = {
'default': {
'BACKEND': 'django_redis.cache.RedisCache',
'LOCATION': 'redis://127.0.0.1:6379/1',
'OPTIONS': {
'CLIENT_CLASS': 'django_redis.client.DefaultClient',
'CONNECTION_POOL_KWARGS': {
'max_connections': 50,
'retry_on_timeout': True,
},
'SOCKET_CONNECT_TIMEOUT': 5,
'SOCKET_TIMEOUT': 5,
},
'KEY_PREFIX': 'myapp',
'VERSION': 1,
}
}
```
### Using Cache
```python
from django.core.cache import cache
# Set with expiration (seconds)
cache.set('key', 'value', timeout=300)
cache.set_many({'key1': 'value1', 'key2': 'value2'}, timeout=300)
# Get
value = cache.get('key')
value = cache.get('key', 'default_value')
# Delete
cache.delete('key')
cache.delete_pattern('user_*')
```
### View Caching
```python
from django.views.decorators.cache import cache_page
@cache_page(60 * 15) # 15 minutes
def my_view(request):
return render(request, 'template.html')
```
### Template Fragment Caching
```html+django
{% load cache %}
{% cache 500 sidebar request.user.id %}
<div class="sidebar">
<!-- Content to cache -->
</div>
{% endcache %}
```
---
## Session Backend
```python
# settings.py
SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
SESSION_CACHE_ALIAS = 'default'
```
Or with Redis directly:
```python
SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
CACHES = {
'default': {
'BACKEND': 'django_redis.cache.RedisCache',
'LOCATION': 'redis://127.0.0.1:6379/0',
}
}
```
---
## Celery Broker
```python
# settings.py
CELERY_BROKER_URL = 'redis://127.0.0.1:6379/0'
CELERY_RESULT_BACKEND = 'redis://127.0.0.1:6379/1'
CELERY_ACCEPT_CONTENT = ['json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'
```
---
## Django Channels with Redis
```python
# settings.py
CHANNEL_LAYERS = {
'default': {
'BACKEND': 'channels_redis.core.RedisChannelLayer',
'CONFIG': {
'hosts': [('127.0.0.1', 6379)],
},
}
}
```
---
## Connection Pool
```python
# settings.py with connection pool
CACHES = {
'default': {
'BACKEND': 'django_redis.cache.RedisCache',
'LOCATION': 'redis://127.0.0.1:6379/1',
'OPTIONS': {
'CLIENT_CLASS': 'django_redis.client.DefaultClient',
'CONNECTION_POOL_KWARGS': {
'max_connections': 100,
},
'PASSWORD': 'your_password',
}
}
}
```
## Redis CLI Commands
```bash
# Connect
redis-cli
# Check keys
KEYS *
# Delete by pattern
FLUSHDB # Clear current database
```
+ ## Best Practices
+
+ ### Connection Management
+
+ ```python
+ # Reuse connection, don't create new each request
+ from django_redis import get_redis_connection
+
+ def get_redis():
+ # Global singleton
+ return get_redis_connection("default")
+ ```
+
+ ```python
+ # Connection pool settings
+ CACHES = {
+ 'default': {
+ 'BACKEND': 'django_redis.cache.RedisCache',
+ 'LOCATION': 'redis://127.0.0.1:6379/1',
+ 'OPTIONS': {
+ 'CONNECTION_POOL_KWARGS': {
+ 'max_connections': 100,
+ 'retry_on_timeout': True,
+ },
+ 'SOCKET_CONNECT_TIMEOUT': 5,
+ 'SOCKET_TIMEOUT': 5,
+ }
+ }
+ }
+ ```
+
+ ### Key Design
+
+ ```python
+ # Use namespaced keys
+ KEY_PREFIX = 'myapp'
+ VERSION = 1
+ # Keys become: myapp:v1:user:123
+
+ # Add TTL to all keys
+ cache.set('temp_token', token, timeout=300) # 5 min
+
+ # Use consistent naming
+ cache.set('user:profile:123', data)
+ cache.set('user:session:123', data)
+ ```
+
+ ### Performance
+
+ ```python
+ # Batch operations
+ cache.set_many({
+ 'key1': 'value1',
+ 'key2': 'value2',
+ 'key3': 'value3',
+ }, timeout=3600)
+
+ # Use pipeline for multiple ops
+ pipe = cache.client.get_client()
+ pipe.set('a', 1)
+ pipe.set('b', 2)
+ pipe.execute() # Atomic, single round-trip
+ ```
+
+ ### Error Handling
+
+ ```python
+ from django.core.cache import CacheKeyError
+
+ try:
+ value = cache.get('key')
+ except ConnectionError:
+ # Fallback to DB or default
+ value = get_from_db()
+ ```
+
+ ### Do:
+
+ - Always set TTL (expire keys)
+ - Use key prefixes for namespacing
+ - Reuse connections (don't create per request)
+ - Use pipeline for batch operations
+
+ ### Don't:
+
+ - Use KEYS * in production (blocks Redis)
+ - Store large values (>1MB consider compression)
+ - Use Redis as primary data store (it's a cache)
+ - Forget connection timeout settings
+
+ ---
+
## References
- **django-redis**: https://github.com/jazzband/django-redis
- **Documentation**: https://django-redis.readthedocs.io/