Quoting Aria Bamdad <a...@biostat.bsc.gwu.edu>:
Hi, I have an installation of Horde Groupware webmail Edition 1.2.2, with IMP 4.3.3 and PHP 5.2.5. The Horde Performance Guide http://www.horde.org/horde/docs/?f=PERFORMANCE.html under IMAP tuning says that if using up-imapproxy, "make sure SELECT caching is turned off". When I do this, I get poor performance because the up-imapproxy unselects the mailbox after every single transaction, so the entire mailbox index structure for a given mailbox has to be reloaded for every single transaction. This is something that the developer of up-imapproxy is aware of.
This should really not be a problem with any recent IMAP server - on servers like dovecot and cyrus, this should be instantaneous (since this information is cached server side). If you are seeing "poor performance" on SELECT/EXAMINE commands, you *really* need to switch IMAP servers.
When I turn on select caching, IMP performance is excellent. My question is why does the above Horde document say to turn off the select caching? Does turning on select caching cause a problem?
Oh yes. Multiple concurrent accesses to a mailbox is bad news with select caching. An APPEND to the current mailbox breaks caching. IIRC, new messages delivered to the mailbox aren't recognized. These are all Bad Things.
Don't use it. IMAP caching needs to be done at the client level, not the proxy level.
michael -- ___________________________________ Michael Slusarz [slus...@horde.org] -- IMP mailing list - Join the hunt: http://horde.org/bounties/#imp Frequently Asked Questions: http://horde.org/faq/ To unsubscribe, mail: imp-unsubscr...@lists.horde.org
