hot key problem
Redis的热Key是指在短时间内被大量请求频繁访问的某个或某些Key，相比其他Key接收更多流量，造成（节点）负载分布不均
Impact of Hot Keys¶
Single-node bottleneck - One Redis node handles all requests
Increased latency - Queue buildup for hot key operations
Network saturation - Large values amplify bandwidth issues
Cluster imbalance - Hot key's slot receives disproportionate load
Cascading failures - Hot key node failure affects many requests
How to Solve the Hot Key Problem¶
Detection - Monitor access patterns to identify hot keys early
Local Caching - Reduce Redis load with client-side caching
Key Splitting - Distribute load across multiple physical keys
Read Replicas - Route hot key reads to replicas
Probabilistic Expiration - Prevent cache stampede with early refresh
Cluster Awareness - Distribute across slots in Redis Cluster