Cyrus 2.4.13 memory use

[Robert Mueller]

> > It looks like 3000 IMAP sessions are going to take around 8 GBytes
> > of RAM just to run, and we will need to buy additional RAM for
> > buffer cache. This isn't the end of the world: memory is cheap. I'm
> > just curious if anyone else saw a similar increase when upgrading
> > from 2.3 to 2.4.
>
> I played a bit fast and loose with memory in 2.4.  You'll find that
> large mailboxes take quite a bit more memory when selected.  It was a
> tradeoff against extra locking.  We could save quite a lot by
> requiring changing

I vote for not adding the extra complexity back.

When a mid-range laptop can come with 8G of RAM, I don't think asking
for more than 8GB RAM on a server running 3000+ simultaneous IMAP
connections is a big ask these days.

http://37signals.com/svn/posts/3090-basecamp-nexts-caching-hardware

Rob