Caching Patterns and Strategies

Why Cache?

Caching reduces latency, decreases database load, and improves user experience by serving frequently accessed data from fast storage.

Common Caching Patterns

Cache Aside (Lazy Loading)

Check cache first. If miss, fetch from database and populate cache.

1. Check cache
2. If miss, fetch from database
3. Update cache
4. Return data

Write-Through

Write data to cache and database simultaneously. Ensures consistency.

1. Write to cache
2. Write to database
3. Acknowledge write

Write-Behind

Write to cache immediately, asynchronously update database. Risk of data loss.

1. Write to cache
2. Acknowledge write
3. Asynchronously update database

Cache Invalidation Strategies

Time-Based (TTL)

Automatically expire cache after a set duration.

Event-Based

Invalidate cache when data changes.

Manual

Explicitly clear cache when needed.

Popular Caching Solutions

• Redis: In-memory data store with rich data types
• Memcached: Simple key-value caching
• Browser Caching: Leverage HTTP caching headers
• Database Query Cache: Native database caching

Best Practices

• Cache the right data (frequently accessed, expensive to compute)
• Set appropriate TTLs
• Monitor cache hit rates
• Use cache warming for critical data
• Implement cache stampede prevention