[imp] login slowness with large inboxes after upgrade from Horde 3.0.10+IMP 4.0.4 to Horde 3.3.8 + IMP 4.3.7

Michael M Slusarz slusarz at horde.org
Thu Nov 4 16:30:47 UTC 2010


Quoting Aria Bamdad <aria at bsc.gwu.edu>:

> Regarding turning caching on, I have done so and have set long periods of
> time for cache expiration delays but even so, a user with several thousand
> messages has a long login delay after a day of inactivity (with IMP).  I am
> not sure how IMP decides when the cache is no longer valid and has to be
> recreated.

For the mailbox listing cache (sort): anytime the mailbox changes.  So  
anytime a mailbox receives a new message, or you delete a message, the  
entire mailbox needs to be resorted.  So mailbox list caches are not  
terribly useful for mailboxes that see a lot of turnover (e.g. INBOX).

But message caching is much more useful: data cached for each message  
is only purged when the UIDVALIDITY for a mailbox change (which, in  
most cases, is never).  message caching prevents us from having to  
grab the message headers, message structure, and the associated  
parsing for every message shown.  This can greatly reduce the network  
traffic between PHP box -> IMAP server, and will speed display since  
parsing complex messages (and MIME-encoded headers) can be expensive  
operations.

> In my case, the only thing that helped was to set the limit on
> sorting to mailboxes of 1000 or fewer messages.  I wish there was a way to
> just turn off sorting at login and still allow for sorting after login.
> Basically,  a parameter that allowed to force the sort order to 'by arrival'
> if mailbox contains greater than X messages.  This way, the client still has
> the option of sorting but does not have a performance problem loggin in.
> With the current configuration options, it's either sorting is enabled or
> disabled.

This could be done with a prefs hook, I believe.  If not, it could be  
accomplished by a postlogin hook.

michael

-- 
___________________________________
Michael Slusarz [slusarz at horde.org]




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