Mastering MySQL 4

Replication is another means of keeping a backup (see Chapter 12, "Database Replication"). It protects against hardware failures on one of the replicated databases, but not against user stupidity or maliciousness! If a user deletes a number of records, this process will then be replicated onto the other replicated servers, making replication useless as a reliable form of backup. If you do replicate, you may be able to worry less about hardware failure, but you still need to make use of another form of backup.