On 25 Jun 2001 20:02:56 -0700, Jeremy C. Reed wrote:
> Does anyone have info on or URLs to some POP3-based maildir vs. mbox
> performance benchmarks that compare messages of varying sizes?
Have a look at
http://www.shub-internet.org/brad/papers/dihses/lisa2000/
I think he has a couple of other
papers in the same directory set as
well. There is a significant
reference list.
Pure mbox pop daemons have to read
the whole mbox and index it each
time - this tends to blow your
caching if you have large mailboxes
- in general its great if people
just grab mail off the server and
delete it, but falls apart for other
access schemes. mbox should not be
used in the presence of NFS.
Brad favours mbox with cached
message metadata as a performance
enhancement - ie separate cached
information on message content
within the mbox.
Maildir can work very very well in
the environment where there are lots
of messages left on the server if
there is some means of preventing
the pop server actually doing work
on each message file for each
session - this can be done by
embedding some additional meta data
- ie by encoding the message size
into the message filename and so
preventing additional stat
operations. Without this
optomisation maildir is poor in
terms of disk ops for mailboxes with
large numbers of messages, and
pretty good for small mailboxes. It
is simple and is NFS resistant.
Cyrus is great for a single sealed
server, does good IMAP (this
information is from 3 years back
when I last played with it in
detail), caches lots of information
around so probably is heavier to
deliver to and light for pop/imap
sessions where not a lot of work
needs to be done. Its a little bit
of a pain to administer, but in
general can be left well alone. It
does not work in the presence of
NFS.
Nigel.
--
[ Nigel Metheringham Nigel.Metheringham@??? ]
[ Phone: +44 1423 850000 Fax +44 1423 858866 ]
[ - Comments in this message are my own and not ITO opinion/policy - ]
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