I have 1 master and 3 replicated slaves.
Every night I perform the following on slave 1:
STOP SLAVE SQL_THREAD
mysqldump ...
START SLAVE
The dump takes about 45minutes, in that time Slave 2 and 3 also lags behind the master, which I dont really understand why, as far as I know Slave 2 and 3 should not be affected by the actions on Slave 1?