[horde] Slow progress...

Michael M Slusarz slusarz at horde.org
Thu Sep 6 01:55:59 UTC 2007


Quoting "Ashley M. Kirchner" <ashley at pcraft.com>:

>
>     Something hit me today as I was going through the lists messages...
> Quoting Andrew Morgan earlier today as he was trying to help Dave
> Cunningham:
>
>        "Are you storing sessions in MySQL as well?  The session table can
>         be a huge burden on MySQL.  A *lot* of data is stored in the
>         session with Horde 3.x.  I've moved sessions off into memcache
>         (running on the same server as MySQL) and it has been a big
>         performance improvement."
>
>
>     Suddenly a light went off.  Yes, I was storing that stuff in MySQL.
> So why not try it.  I switched the method to PHP files instead (which in
> turn uses memcache) and suddenly the problematic user could log in!  So
> then what was the problem?  The data being stored in the session?
>
>     The session file for this particular user was close to 2MiB in
> size.  Holy toledo, WHY?  Open further investigation I found out that
> when the user logged in, IMP was storing a directory listing of
> *EVERYTHING* in this user's $HOME folder in the session data.  WHY IN
> THE WORLD??!
>
>     The next thing that jumped out at me was that while in IMP, if you
> looked at the available folders for saving e-mails, you got that listing
> again, every single file in this user's $HOME folder, some 6,000 of
> them.  So no wonder it was timing out trying to generate that list
> first, and then trying to inject the whole shebang into the session
> table.  Now to figure out how to not have it do that.
>
>     Turns out that IMP is configured to NOT use IMAP subscriptions by
> default.  And once I turned on that config option, suddenly logging in
> went much faster and everything worked a whole lot better.  Looking at
> the session file, it went from the original 2MiB to 47K and it ONLY
> contains what's in the user's $HOME/mail folder (which agrees to the
> IMAP subscription file as well.)
>
>
>     So now my question: why oh why does IMP need to store the ENTIRE
> user's $HOME contents in a session handler?  I can understand the
> argument that not everyone uses IMAP subscriptions, or not everyone
> stores their mail folder under $HOME/mail, but ferkryingoutloud, if they
> have several thousand files in their account (under $HOME), this problem
> will continue to happen.  A better solution has to be implemented somewhere.
>
>     I didn't see an option in the main configuration (when you're horde,
> setting up IMP) that would've allowed me to set the default to use IMAP
> subscriptions.  It's not till after the user logs in that they can set
> that configuration option.  This is going to cause problems with a lot
> of my users once I make this system live.
>
>     Now I can finally continue to install the other bits and pieces and
> test things as I go along...

Dollars to donuts you are using UW-IMAP.  And it sounds like you  
haven't read the documentation.  Specifically:
http://wiki.horde.org/ImpUWIMAPNamespaces

michael

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



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