Redis 通过 复制(数据的副本)、Redis Sentinel(自动故障转移监控)和 Redis Cluster(分片 + 复制)提供 高可用性。理解这些对于在生产环境中可靠地运行 Redis 很重要。
复制 — 主节点和副本
PRIMARY (master) → handles writes; asynchronously replicates data to replicas
REPLICAS (slaves) → copies of the primary's data; can serve READS (read scaling)
Write → Primary → async replication → Replicas (eventually consistent)
✓ Redundancy (replicas have copies) + read scaling (reads offloaded to replicas)
✗ Replication is ASYNC → a small lag; a failover could lose very recent writes
