Currently I'm studying Percona's xtrabackup. In the manual in the paragraph "Taking Backups in Replication Environments" it says that using the
option is always recommended and I understand the reasons behind it.
I'm just wondering now, if there is actually a difference in the result when I do not use this option. After applying the logs on a backup, I don't see why there should be a difference between a backup taken with or without this option.
I'm asking, because in our production environment we do not use this option. The backup runs at midnight, but it failed this night. The backup is taken on a slave and I'd have a bad feeling about stopping the SQL thread now to take the backup.