Scaling and high availability for MySQL

It is important to consider scaling and high availability as important considerations for any database system, especially for large-scale and mission-critical applications. There are a number of strategies that MySQL provides for scaling and achieving high availability, including:

1. Master-slave replication:  Using master-slave replication, you can replicate data from a master server to one or more slave servers, offering a way to scale read-intensive workloads from a master server to a slave server. As a primary source of data, the master server serves as a source of information, while the slave servers serve as read-only sources of information.
2. Load balancing: The purpose of load balancing is to distribute database requests across multiple servers so that performance and reliability are improved. There are several load balancing strategies supported by MySQL, including round-robin, least connections, and weight-based load balancing strategies.
3. Cluster/Sharding:  Clustering/Sharding: Clustering and sharding are both methods of scaling database systems horizontally, by splitting data between multiple servers in order to make them more elastic. As a result, you will be able to distribute the load more evenly, which will improve performance, while also increasing reliability by reducing the impact of any failures on the system.
4. Read-only replicas: There are read-only replicas that can be used to scale read-intensive workloads by replicating data from a master server to one or more read-only replicas as a means of scaling read-intensive workloads. In this way, you will be able to offload read-only queries from the master server in order to improve performance and reduce the impact of read-intensive workloads on the master server.
5. Automatic failover:  When the primary server fails, it can automatically failover to a secondary server. This provides a way for a failover to be performed in the event of a primary server failure. In this way, high availability is ensured and downtime is minimized.
6. Backups: It is important to keep regular backups as a way to ensure that data can be recovered in the event of a failure and as an important part of any high availability strategy. There are several backup strategies that MySQL supports, including hot backups, cold backups, and incremental backups.

It is worth noting that scaling and high availability are important considerations for any database system, and MySQL provides a number of strategies for achieving these goals. 

It is possible to improve performance, increase reliability, and ensure that your database is always available by using a combination of these strategies.