[imp] [horde] large session entries in horde_sessionhandler

[liam hoekenga]

Picking up a conversation from the Horde list.. the thread can be seen at:

http://marc.theaimsgroup.com/?l=horde&m=111636233218340&w=2

>> No.  By default, IMP *doesn't* store the body contents in the session
>> for the very reason it has the possibility of creating extremely large
>> sessions.  This new config item is designed for those of us running IMP
>> on small systems with minimal users to take advantage of caching the
>> bodytext also.

I have noticed some strange behavior...

On our production servers, as soon as I log in to Horde, my entry in
the session table includes about 23k of text in session_data.

On our development servers, the same action generates a much smaller
session_data (it only contains an array for hordeMessageStacks).

Same software, same hardware, only difference is the amount of load the
machine sees.  Does horde cache more when it's heavily loaded?  Is there a way
to limit the amount of information it caches in the session?

Michael suggests that IMP doesn't store body contents in the session,
but we've seen otherwise.  Our sessions contain messages - although I don't know
if they're the last message read, or the message currently being read, if these
messages contain attachments, the session data can grow quite large.  I don't
think it's reasonable to suggest that the way to fix that is to limit the size
of the messages our users receive.

Is the cache system at all related to this?  We've currently got it set
to cache objects in the filesystem, in a location determined by
Horde::getTempDir(). I don't really see anything in /tmp or /var/tmp.. could
this stuff be getting stuffed in the session?

Liam