In our production environment, the configuration for binlog format is Row and there will be one master following by 2 or more slaves. in this case, there will be a lot of binlog generated when the pressure on master is high, as there is no method for master to control the speed for sending binlog events to slaves. the net work is occupied by transferring binlog events. as a result, request for clients will be blocked at the network side.

So we have to limit binlog send speed to solve problem above.