How to switch the master and slave mode of redis
There are two methods for switching Redis master-slave mode: direct switching and Redis-Sentinel auxiliary switching. Direct switching requires manual operations, including deactivating the master server, syncing data, disassociating and connecting to new master nodes. Redis-Sentinel provides automatic switching, requiring additional configuration of Sentinel and failover elections. Both methods may cause short-term data unavailability during the switching period and should be backed up before the operation.
How to switch between Redis master and slave mode
Switch directly
- Deactivate the master server: temporarily stop the master server so that it cannot receive write operations.
- Synchronize the data of the master node to the slave node: Use the BGSAVE or SAVE command to synchronize the data of the master node to the slave node.
- Make the slave master: Use the SLAVEOF NO ONE command to disassociate the slave node from the master node, and then use the INFO command to obtain the address of the new master node.
- Make the old master node a slave: Use the SLAVEOF
command to connect the old master node to the new master node.
Redis-Sentinel Assisted Switching
Redis-Sentinel is a tool for Redis high availability, which can automatically complete master-slave switching.
- Configure Sentinel: Install and configure Sentinel to monitor the master and slave cluster.
- Deactivate the master server: Sentinel will automatically detect the master server failure and start failover.
- Election of a new master node: Sentinel will elect a slave node from the cluster to become the new master node.
- Slave node switching: Sentinel connects all other slave nodes to the new master node.
Notice:
- Be sure to make a backup before performing any switching operations.
- During the switchover, data may be temporarily unavailable.
- Redis-Sentinel provides a smoother and more reliable switching experience, but requires additional configuration and maintenance.
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