Mastering MariaDB

Checking the replication for errors

Calculating checksums is the best way to be sure that a server and a slave contain exactly the same data as the server. This check can be used in two situations:

• After loading data into a slave, to be sure that everything worked properly
• On running servers, on a regular basis, or when we suspect that a replication error happened

The second case is more complicated, because during the normal execution slaves can lag behind their masters. However, a tool explained next is able to perform this check automatically, by waiting until slaves reach a certain binary log event.

There are at least three methods to do this:

• Using the CHECKSUM TABLE statement
• Using the Percona pt-table-checksum tool
• Calculating a checksum of the ...