Comment 9 for bug 589512

Peter,

Please also read updated documentation
http://www.percona.com/docs/wiki/patches:slow_extended#log_slow_slave_statements

To start the logging from the slave thread, you should change the global value: set global log_slow_slave_statements=ON; and then execute: STOP SLAVE; START SLAVE;. This will destroy and recreate the slave SQL thread, so it will see the newly set global value.

To stop the logging from the slave thread, you should just change the global value: set global log_slow_slave_statements=OFF; and the logging stop immediately.