Redis / Cache

The Redis concurrency-competition problem and solutions using atomic commands, mutexes, optimistic locking, and Lua scripts.

Redis command execution flow, slow-query configuration and commands, and the in-memory FIFO implementation.

What Redis blocking is, how to discover it, and internal and external causes including complex commands, CPU saturation, persistence, swap, and network problems.

What a Redis big key is, its risks, how to find and delete it, and the basic mitigation of splitting it into smaller keys.

What a Redis hot key is, how to discover it, and how to mitigate it through key replication or local caching.

1. Why Redis Cluster is needed - Distributed system partitioning 2. What Redis Cluster is - Redis's distributed solution, solving the single-machine write-capacity limit of primary-replica replication and the lack of automatic failover 3. How to build a Redis Cluster

1. Why Redis Sentinel is needed - Primary-replica replication cannot perform automatic failover 2. What Redis Sentinel is - Redis's high-availability mechanism, solving the lack of automatic failover in primary-replica replication 2.1. Redis Sentinel functions - Monitoring, Notification, Automatic failover, Configuration provider

1. Why Redis Replication is needed - Distributed system replication 2. What Redis Replication is - Copy data into multiple replicas and deploy them on other machines - Replication is the foundation of Redis high availability (Redis Cluster/Redis Sentinel) 2.1. Replication topology

Redis key expiration commands and passive and active expiration mechanisms.

Redis memory consumption, fragmentation, memory inspection, eviction, key expiration, and optimization.