We run several frontend servers (Linux/Apache/PHP) behind a load balancer.
Each frontend is also a MySQL slave, and all queries are done locally
(all changes go directly to the master). The problem is, whenever
somebody makes a lot of changes to the database at once (deletes, updates,
or adds a lot of rows), the slave thread loads up the server to the point
where Apache doesn't get much CPU anymore, and then our sites slow way
Is it possible to set either set the priority ('nice') of the Slave thread
down so it doesn't do that? Or, alternatly, is there a way to limit the
slave thread to only "X" bin-log transactions per second? We don't much
care if the frondends aren't updated at exactly the same second (or even
the same minute, just so we have the appearance of real-time), so we'd
prefer to slow down the slave process in an effort to keep Apache fast...
Thanks for any advice,