Cache-aside is the caching pattern you'll use most, and probably the one you already use without knowing its name. The application checks the cache first, and on a miss, loads from the database and populates the cache itself. It's simple, it puts the application in control, and it degrades gracefully when the cache is unavailable. Understanding it well (including the two subtle bugs it invites) is the foundation for every other caching pattern in this module.
This is part 9 of the Redis Masterclass and the start of the caching module, following key expiration and TTL.
The pattern
Cache-aside (also called lazy loading) has the application manage the cache directly. On a read:
Check Redis for the key.
