[plug] Mailbox speeds (was [OT] Gmail Opinions)

[Craig Ringer]

Trevor Phillips wrote:
> On Friday 18 June 2004 11:38, Bernd Felsche wrote:
> 
>>Cyrus keeps meta-information...
>>	cyrus.cache
>>	cyrus.header
>>	cyrus.index
>>at each mail "folder" level.
> 
> So it does - yet it's still loading up files, searching, & closing 'em on a 
> request, which for small requests is slow. I have no idea how "flat" they 
> are, or if they're optimised for quick-searching.

If you want quick searching under Cyrus, "man squatter". It lets you 
build wonderful full-text indexes of mailboxes, which when combined with 
IMAP's server-side search means _incredible_ speed. I can do a keyword 
search of a couple of 10,000 message mailboxes very quickly.

You don't need squatter unless you're doing full text searches, though. 
the other cyrus.* files provide quite enough info for fast, indexed 
searches on message headers.

As for the small files issue - run Cyrus on reiserfs if you possibly 
can. It made a _massive_ performance difference for me.

Oh - all this applies to Cyrus 2.1 and 2.2 . If you're running an older 
version, it's WELL beyond time to upgrade - the improvements are incredible.

As for the DB storage issue - requests are periodically made by 
relateively new Cyrus users on the Cyrus lists, asking for RDBMS storage 
of the indexes etc. The developers tend to respond that they have yet to 
see any case where they think it could be faster than the current 
method. I'm quite willing to believe them :-)

Overall I find Cyrus to be incredibly fast, stable and efficient. I'm 
yet to see another mail system I'd even consider using after using 
Cyrus. My only issue is with its use of BDB, and most issues with that 
turn out to be BDB configuration problems rather than real issues with 
BDB or Cyrus anyway.

--
Craig Ringer