However, we’ve seen InnoDB Hot Backup cause cpu usage to spike, though to be fair, it spikes more after the backup is done, during scp :) if there are problems we just “nice” the process and it’s all set.

Which is why mysqlhotbackup is wrongly named, and should have been called “mysqlwarmbackup”.

While using `mysqldump –single-transactions` on InnoDB only database is indeed a hot backup (it’s even consistent),
InnoDB-Hot-Backup, is even hotter (”Searing backup?”), since it almost does not impacts the running server (load average is almost unaffected). With mysqldump, a performance drop is noticeable.