MySQL Performance Blog

Using xtrabackup for copying files can really saturate your disks, and that why we made special option --throttle=rate to limit rate of IO per second. But it really works when you do local copy.
What about stream backup ? Even you copy just to remote box with
innobackupex --stream=tar | ssh remotebox "tar xfi -"
, read may be so intensive so your mysqld feels impact, slave getting behind, etc…

For this there is a nice small utility – pv .

With pv you run:
innobackupex --stream=tar | pv -q -L10m | ssh remotebox "tar xfi -"

and it will limit channel rate to 10 M per second.

I should say I can see results of new engineering/refactoring/bug hunt efforts inside Sun/MySQL.
Over last couple of weeks I started getting a lot of messages from the bugs system about bugs I reported long ago which were deferred to be fixed later or were left in open state. Here is example of such a bug.

I really hope this effort will result in a lot of these old annoyances fixed, which really matches my vision for MySQL – we do not need more big features we need old ones to work well and be convenient.