[imapproxy] configuration advice [was :ImapProxy session issue ]

[Eric Rostetter]

Quoting G G Papazoglou <grp at med.uoc.gr>:

> > I have about 6,000 unique users per day.  Peak concurrent usage is
> > 1,200 sessions.  I currently have a seperate Solaris 9 box ready to
> > perform the imapproxy function, since previously imapproxy became
> > unresponsive when I put it into production.

I'll reply further to this original post when I get time.  My advice for now
is to test it well.   This is because I've had trouble in the that past with
imapproxy, which seems to have been fixed when I upgraded my imap server.
So I know first hand that it will work or not based on how buggy your imap
server is.  Also, of the 3 or 4 performance reports to the imapproxy list,
the worst performing one was on solaris.  Since you are using solaris, you
will want to be a bit weary.  I think the other one might have been solaris
8 though, so it may or may not apply.

There is an expect script you can use, which will tell you if imapproxy
itself is working at all for you.  It is in the imapproxy cvs now.  See
the PERFORMANCE file (in docs/ I think) for info.  This will tell you 
what kind of imap performance increase you will see.  But it won't tell
you how that will affect the performance of IMP per se.
 
> This is right for me too, it's kind of difficult to check the
> performance.

For all of us; it is kind of a subjective thing.

> Yet, compared to yours, my installation seems minimal...I
> have about 1,000 users in total, perhaps 10 or 20 concurrent sessions max,

I'm inbetween those.  About 2K users total, during peak maybe 30-50 
concurrent users in IMP.  Many others using other imap/pop3 users.  Lots of
sendmail activity.  Very busy, but most don't use IMP while at work (more
used when out of the office than in the office).

> great. Although after I read all your replies I tend to think that for
> such a minimal installation like mine imapProxy would be unnecessary.

It isn't necessary, but it could well improve performance.  There are certain
operations that require IMP to hammer the server, and while that is not going
on most of the time, when it does it will help.  Also, if you have users like
me who read a lot of small mails really fast (about a message every 4-5
seconds sometimes) then it will really speed up their experience.  So even
with the smallest site, it will help in certain situations.  Maybe your overall
experience isn't impacted, but the speed of some special case situations will
be improved, and that is a good thing.

There are two uses for imapproxy.  The first is to take some of the load off
your imap server.  If your imap server is overloaded then this is why you want
it.  In your small setup, this probably isn't an issue.  The second reason is
to speed up IMP.  This is where you will see the benefit.

> Am I wrong?

Depends on your goals.

> Greg

-- 
Eric Rostetter
The Department of Physics
The University of Texas at Austin

Why get even? Get odd!