What does the Redis Sentinel mode refer to?

The Sentinel mode in Redis is an architecture design used to achieve high availability. In Redis, the Sentinel mode monitors the health status of the master and slave nodes, and automatically performs failover to ensure continuous availability of the system.

Specifically, the Sentinel mode usually consists of multiple Redis Sentinel processes, which are responsible for monitoring the status of the Redis master node and slave nodes. When a master node fails, the Sentinel will coordinate the election of a new master node and switch the slave nodes to the new master node to achieve fault recovery. This process is completely automated and does not require manual intervention.

It’s important to note that sentinel mode not only detects the failure of the master node, but also monitors the status of the slave nodes, and can promote a slave node to master when needed. This can effectively improve the reliability and stability of the Redis system, ensuring continuous service availability.