[imp] Permformance issue

[Terry Poperszky]

Ok, running SuSE 8.0 and WU IMAP (Mbox), I was able to open a directory with
800 emails in about 4 seconds. I think indicates that the slowness was due
to accessing Exchange through IMAP.

Thanks for everyone's help.

Terry Poperszky MCSE, CCNA
Network Manager
SOS Staffing Services 
801-257-5706
Terry.Poperszky@SosStaffing.com



-----Original Message-----
From: Eric Rostetter [mailto:eric.rostetter@physics.utexas.edu] 
Sent: Tuesday, July 16, 2002 4:51 PM
To: Terry Poperszky
Subject: RE: [imp] Permformance issue

Quoting Terry Poperszky <Terry.Poperszky@SosStaffing.com>:

> Still pointing to the Exchange server via IMAP. Initial opening of a mail
> box with 563 messages was 45 seconds, subsequent refreshes took about 8-10
> seconds. Based on what I have been reading in the list this is not normal.

No, that is not normal!  I certainly would not be happy with that kind
of performance!  (I would say anything more than 4 seconds is out of the
questions, unless you're half-way across the world...)

But, to answer your other question now: No, that kind of speed issue is
not inherent in Horde/IMP.  There is something else coming into play.

Check your setting in horde/imp/conf.php where it says something about
"show attachments" and notes that it is a performance hit.  Turn that
off if it isn't, but it should be off by default.  (I actually have it
on in my setting, but that's another issue).

> The moves between pages do not seem to be significantly delayed, only when
> accessing the mail server, so that is where I'll start.

Unfortunately IMP hits the IMAP server a lot.  Since there are no 
persistent IMAP sessions in PHP, IMP hits the server for just about
every page for authentication.  

If you are not seeing slowdowns when switching between pages that don't
retrieve a message or do a folder lookup, then you can elinimate a lot
of possible problems.  As that would mean the connection to the IMAP server
and the authentication to the IMAP server are working at a reasonable speed.
So the slowness would be in the message/folder access, not the machine
access or authentication process.

You might compare the speed of folder operations (the Folder View) versus
message operations (the Message View or viewing a message) and see if you
can determine if the folders are the/an issue or not.  If the folders seem
slow, it may be a configuration option in IMP...

> I am currently
> building the IMAP installation on the sendmail box and will compare access
> times once it is up and running. Thanks to everyone for their input. 

Will be interesting to see what you come up with in that test.

There are also php accellerators you can use to speed up Horde/IMP.  But
they will not help in your situation.  After you get Horde/IMP working
at a reasonable speed, then you can consider things like PHP accellerators,
ssl accellerators, etc.

> Terry Poperszky MCSE, CCNA
> Network Manager
> SOS Staffing Services 
> 801-257-5706
> Terry.Poperszky@SosStaffing.com
> 
> 
> 
> -----Original Message-----
> From: Eric Rostetter [mailto:eric.rostetter@physics.utexas.edu] 
> Sent: Tuesday, July 16, 2002 12:09 PM
> To: Terry Poperszky
> Cc: 'Eric Rostetter'; 'imp@lists.horde.org'
> Subject: RE: [imp] Permformance issue
> 
> Quoting Terry Poperszky <Terry.Poperszky@SosStaffing.com>:
> 
> > I am in the midst of converting a network that was entirely MS based to
a
> > mixed OS (Linux/MS) environment. MS Exchange is top on my hit list at
the
> > moment, but I have to provide suitable replacement services before I can
> > replace it. Horde/Imp (Using IMAP) is the probable replacement for
Outlook
> > Web Access, but it simply isn't as quick as Web Outlook. I am looking to
> see
> > whether that is inherent in the program, or is a function of my
> > installation/infrastructure.
> 
> Are you hitting a seperate IMAP server, or the MS Exchange IMAP server, 
> with Horde/IMP?  And what is your acceptable response time? (i.e. what
> is the response time of the Web Outlook currently?)
> 
> Using a Dell 2400 2x600mhz, 512MB sdram, battery backed 128MB cache
> raid controller with 6 disk Raid 5 logical volume for everything,
> Postgresql/Horde/Apache/wu-ftpd with mbox format, RedHat Linux 6.x,
> I can support 1000 users no problem.  And that is with the machine
> doing other stuff too, and very heavy load.
> 
> Average time to open a mailbox of 1000 messages is about 1 second.  
> Average time to retrieve a  message for display is about .4 - .8 seconds
> depending on the message size.
> 
> Now, I've tested it also with other imap servers and other messages store
> formats (wu-imapd without mbox format store) and it is even faster yet
> with some other configs.  In my case, the message store (mbox) is a big
> performance hit, but I like it anyway, and can live with the performance
> hit.
> 
> So, your question is: is Horde/IMP slow, or something else?  I don't know.
> But the most common non-Hore/IMP bottle necks would be database access,
and 
> imap server performance based on the underlying message store.  So this is
> were I would check first if you don't think you are getting acceptible
> performance for your hardware setup.
> 
> > My base network configuration revolves around three boxes (MySQL,
> SendMail,
> > Apache/php)) all boxes are in running SuSE 8.0, have at least 800 Mhz
> > processors, plenty of disk space and sufficient memory. They are
connected
> > via 100Mb FDX with their own ports on a central switch. I am not showing
> > anything on the wire that would/should cause poor performance.
> 
> Sounds like your cpu, memory, disk, and network are sufficient.  So
> splitting
> the boxes shouldn't result in any real performance hit.  Probably
> advantages,
> since you don't have an SMP machine.  If I didn't have an SMP machine(s),
> then I would probably split things up between machines asap.
> 
> On an SMP machine, I can service web requests, IMAP requests, and database
> requests at the same time, and thus there isn't a real bottle neck.  On a
> uni-processor machine, you can only do one at a time, and under any real 
> load this will cause a bottle neck, and a bottle neck that can be eased 
> by splitting between multiple machines.  So, if you are dealing with the
> hardware you seem to say you have, then I would say you would probably 
> get a big advantage, at least at high load times, by splitting your web
> and IMAP services between two machines.
> 
> On the other hand, I run two installs of Horde/IMP on a two 2-cpu boxes,
> everything on one box, without problem.  I also run it on a 4-cpu box
> without problem.  I wouldn't want to do that on a slow, single cpu box
> though -- even if average performance was okay, it would crash and burn
> in certain situations...
> 
> > Terry Poperszky MCSE, CCNA
> > Network Manager
> > SOS Staffing Services 
> > 801-257-5706
> > Terry.Poperszky@SosStaffing.com
> 
> -- 
> Eric Rostetter
> The Department of Physics
> The University of Texas at Austin
> 
> "TAD (Technology Attachment Disorder) is an unshakable, impractical
devotion
> to a brand, platform, product line, or programming language. It's
relatively
> harmless among the rank and file, but when management is afflicted the
> damage
> can be measured in dollars. It's also contagious -- someone with
sufficient
> political clout can infect an entire organization."
> 
> --"Enterprise Strategies" columnist Tom Yager.


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

"TAD (Technology Attachment Disorder) is an unshakable, impractical devotion
to a brand, platform, product line, or programming language. It's relatively
harmless among the rank and file, but when management is afflicted the
damage
can be measured in dollars. It's also contagious -- someone with sufficient
political clout can infect an entire organization."

--"Enterprise Strategies" columnist Tom Yager.