Shulou(Shulou.com)06/01 Report--

The editor in this issue will bring you about the role of the sentinel mode in the redis cluster and analyze and describe it from a professional point of view. I hope you can get something after reading this article.

Sentinel mode is a cluster deployment method officially recommended by Redis. Unlike master-slave replication, Sentinel mode can automatically switch between master and slave when Master goes down. The Sentinel itself is also an independent process that monitors multiple master-slave replication clusters.

advantage

Monitor whether the Redis cluster is running well from time to time.

If the Redis node fails, you can work with other processes, such as the client.

It can automatically switch between active and standby processes.

Sentinel cluster

Obviously, the Sentinel process also has the problem of single point deployment, that is, after the Sentinel process dies, the entire cluster is unavailable, so the Sentinel process should also support cluster deployment. The advantages of deploying a Sentinel cluster are as follows:

Even if some Sentinel processes fail, you can still switch between active and standby.

The client can connect to any Sentinel process service to obtain cluster information.

Overview of Sentinel Model

Sentinel mode is a special mode. First of all, Redis provides the command of Sentinel. Sentinel is a separate process, which runs independently as a process. The principle is that the sentry monitors multiple Redis instances running by sending commands and waiting for the Redis server to respond.

The sentinels here serve two purposes.

Send a command to get the Redis server back to monitor its running status, including the master server and the slave server.

When the sentry detects a master outage, it automatically switches slave to master, then notifies other slave servers through publish-subscribe mode and modifies the configuration file to switch hosts.

However, there may be problems when a sentinel process monitors the Redis server, so we can use multiple sentinels to monitor it. There is also monitoring between sentinels, which forms a multi-sentinel mode.

The above is the role of the sentinel mode in the redis cluster shared by the editor. If you have similar doubts, it will not hinder your understanding with reference to the above analysis. If you want to know more about it, please follow the industry information.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.