I need to improve backup of databases that won't load production server. I read that good solution to do that is to set database replication and do mysqldumps on slave server.
But description of "replicate_do_db" says that updates won't work with cross-database queries. And here is a problem - I have a lot of PHP apps (few of them are really old) so I have no guarantee that they not use this kind of queries. And I don't want to have out-of-sync databases...
Is there any alternative? Or just use replication only for well-known apps, and mydumper/mysqldump for other?
I know that Percona XtraBackup exist but I want to have backups in .sql format.