Why exactly is --skip-slave-start recommended with MySQL `START SLAVE UNTIL`?

Question

When issuing START SLAVE UNTIL on MySQL , I'm getting the following:

Warning: It is recommended to use --skip-slave-start when doing step-by-step replication with START SLAVE UNTIL; otherwise, you will get problems if you get an unexpected slave's mysqld restart.

Why exactly is it recommended to use --skip-slave-start? What happens if the slave indeed restarts - does it only forget the UNTIL part and replicates till the end of binlog?

Answer 1

Does it only forget the UNTIL part and replicates till the end of binlog?

That's right.

If a previously configured slave is started without --skip-slave-start, then it will use the information stored in master.info to automatically reconnect and continue replication like normal - that is without the UNTIL clause. Which means proceeding to the end of the binlog and waiting for new binlog events.