Redis vs Memcached: Feature Comparison
| Feature | Redis | Memcached |
|---|---|---|
| Data Types | Supports strings, hashes, lists, sets, sorted sets, streams, bitmaps, hyperloglogs | Strings only |
| Persistence | Yes (RDB snapshots, AOF) | No |
| Replication | Yes (with automatic failover) | No |
| High Availability | Yes (Multi-AZ, automatic failover) | No |
| Cluster Mode | Yes (native support) | Partial (manual configuration) |
| Pub/Sub | Yes | No |
| TTL (Expiration) | Yes, per key | Yes, per key |
| Memory Management | Configurable eviction policies | Simple LRU or TTL-based |
| Security | Supports authentication and encryption (TLS) | Basic |
| Use as Persistent Store | Yes | No |
When to Use Redis
Redis is a good fit when you need:
- Advanced data structures (e.g., lists, sets, sorted sets)
- Pub/Sub messaging
- Persistence or snapshotting
- High availability or multi-AZ support
- Clustering and scalability
- Features like atomic operations, transactions, or stream processing
Typical use cases:
- Session storage with failover
- Leaderboards and scoring systems
- Rate limiting and counters
- Real-time analytics dashboards
- Messaging queues or pub/sub systems
- Caching with fail-safe data recovery
When to Use Memcached
Memcached is a good fit when you need:
- A simple, high-speed, in-memory key-value cache
- Low overhead and high throughput
- Stateless, short-lived data with no need for recovery
- Minimal operational complexity
Typical use cases:
- Page and object caching for web apps
- Simple session storage (where persistence isn’t needed)
- Fronting databases or APIs with low-latency access
- High-throughput caching layers (e.g., for microservices)
Let me know if you’d like help choosing between them for a specific architecture or workload.