Cyrus infrastructure performance less than expected

[Robert Banz]

>
> I don't have any system log that complains about something and the  
> only
> Cyrus message I got is a DB4 warning about lockers. I think the DB4 in
> question is the TLS sessions cache DB and in my case the number of
> lockers can be as high as 8 000...

Dump Berkeley DB with a quickness, and switch to skiplist.

That said, there's something to be said about not putting all of your  
eggs onto one server -- virtualized or not.

-rob