How do MySQL tables get corrupted? There are many ways to spoil data files. Often, corruption is due to defects in the underlying platform, which MySQL relies on to store and retrieve data - disk subsystem, controllers, communication channels, drivers, firmware or other hardware faults. Data corruption can also occur if the MySQL server daemon restarts suddenly, or your server reboots due to a crash of other OS components. If the database instance was in the middle of writing data to disk, it could write the data partially which may end up with a page checksum that is different than expected. There have also been bugs in MySQL so even if the server hardware is ok, MySQL itself can cause corruption.

Usually when MySQL data gets corrupted the recommendation is to restore it from the last backup, switch to DR server or take down the affected node if you have Galera cluster to serve data immediately from other nodes. In some cases you can't - if the backup is not there, the cluster was never set up, your replication is down for a very long time, or the DR procedure was never tested. Even if you have a backup, you may still want to take some actions to attempt recovery as it may take less time get back online.