Redis master-slave mode, sentinel cluster, fragment cluster

A master-slave mode ：

characteristic ：
1. Master data can be read and written , Read only from database
2. The host is down , You can only read

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Sentinel mode ： Used to monitor the main server hang up

Since our master node is down, we can only read , Then we have the sentinel mode , The role of the sentry is , When our master node hangs up , Then the sentinel selects a slave node from the slave node as the master node

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Fragmentation cluster

If there is 15000 data , The first deposit 1 To 5000, Second deposit 5001 To 10000, Third deposit 10001 To 15000

What if one of them goes down ：

It is a master-slave mode for each node , When the master node goes down, the slave node makes up

Another point is because of our master-slave mode , Read data from the main library , That is, the main database needs to write data to the read database , Then there will be some pressure on the main warehouse , So how can we solve this problem ？？

Master slave mode