What is the method for achieving high availability in MySQL?

There are several methods for achieving high availability with MySQL.

1. Master-Slave Replication involves configuring one MySQL server as the master and other servers as slaves. All write operations on the master server are replicated to the slaves, which can only read data. In case the master server fails, one of the slaves can be promoted to be the new master.
2. Master-Master Replication: Multiple MySQL servers are configured as master servers, replicating bidirectionally with each other. Each server can handle read and write operations, with data being synchronized between all servers. If one master server goes down, the other master servers can still continue to provide service.
3. MySQL Cluster: Utilizing MySQL Cluster technology to establish a cluster of multiple servers, each with its own replicated data. In the event of one server crashing, the other servers can continue to provide services and automatically restore the data on the crashed server.
4. Database mirroring is a method of replicating data to another server in real-time to create a mirror image of the data. If the primary server fails, the mirror server can be promoted to the new primary server. The mirror server can be configured for hot backup to immediately take over the work of the primary server.
5. Database sharding involves splitting a large database into multiple smaller databases distributed across different servers. Each database only stores a portion of the data, and queries are routed to the appropriate database based on sharding rules. This can improve query performance and scalability, while reducing the impact of single points of failure.

These methods can be selected according to specific needs and environments to provide high availability MySQL services.