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Date:  Wed, 8 Mar 2006 12:30:26 +0800 (SGT)
From:  patricko (at mark) staff.singnet.com.sg
Subject:  [coba-e:04263] Re: fyi:  Re: Optimizing qpopper or POP3 alternative
To:  coba-e (at mark) bluequartz.org
Message-Id:  <Pine.LNX.4.44.0603081222200.14054-100000 (at mark) staff.singnet.com.sg>
In-Reply-To:  <00ea01c64232$67ebea30$2f427dd1@chrism>
X-Mail-Count: 04263

Hi,

If you aint comfortable with recompiling Qpopper,
then the below optimization are for you.







Somemore optimization - *** Recommended by me ***
Changes below:


*** Optimizing Settings found in SUN Cobalt forum ***
vi /etc/pam.d/pop3
#%PAM-1.0
auth       requisite    /lib/security/pam_nologin.so
auth       requisite    /lib/security/pam_shells.so
#auth       required    /lib/security/pam_pwdb.so shadow nullok
#account    required    /lib/security/pam_pwdb.so
auth       required     /lib/security/pam_stack.so service=system-auth
account    required     /lib/security/pam_stack.so service=system-auth



*** Run Qpopper in server mode ***
vi /etc/xinetd.d/pop3
# qpopper config file for xinetd
service pop-3
{
        flags       = REUSE NAMEINARGS
        socket_type = stream
        protocol    = tcp
        wait        = no
        user        = root
        server      = /usr/sbin/in.qpopper
        server_args = in.qpopper -s -R -S
        disable     = no
        instances = 400
        #per_source = 10
}


*** Rebuilt /var/db integrity ***
*** Warning will take some times - do it in maintanence day ***
/etc/rc.d/init.d/dbrecover stop
/etc/rc.d/init.d/dbrecover start


Cheers
patrick





On Tue, 7 Mar 2006, Chris McGinnis wrote:

> I was having hell with my CentOS4.2/BQ box and qpopper.  In 
> /etc/xinetd.d/pop3 I changed the server_args to say:
> 
> server_args = in.qpopper -S -R
> 
> -R = Disables reverse lookups on client IP addresses.
> -S = Enables  server  mode.  This mode reduces disk I/O and disk space usage 
> when popper is used on a system that serves
>               POP only users exclusively.
> 
> Today the server has run without any issues at all.  So it appears to have 
> fixed the problem for now.  However, I'd still like to look into using 
> Dovecot as an alternative.  Maybe I'll get around to testing it sometime 
> soon.
> 
> 
> ----- Original Message ----- 
> From: "Rusty Waybrant" <rwaybrant (at mark) gramtel.net>
> To: <coba-e (at mark) bluequartz.org>
> Sent: Tuesday, March 07, 2006 2:46 PM
> Subject: [coba-e:04261] fyi: Re: Optimizing qpopper or POP3 alternative
> 
> 
> >I have a BQ server that seems to be affected by this POP3 issue as well.
> >
> > After upgrading from FC1/BQ to CentOS4.2/BQ, the POP3 issue remains. From 
> > the client-side of POP3, it seems to hang on authentication, specifically: 
> > "pass ****", and occasionally getting the EOF or I/O error. Once this 
> > starts, every new attempt for POP3 just builds up until there is 80-120 
> > POP3 sessions ESTABLISHED (netstat). There are a few "-ERR POP EOF or I/O 
> > Error" in the logs during the time of high usage, but for the most part, 
> > this is just timeout errors on the client-side.
> >
> > On the old server, it required the updated pwdb RPM and needed to run a 
> > db_recover, and then kill off all the current POP3 sessions to resolve the 
> > issue... I searched around and this looks like this is replaced by 
> > "/etc/rc.d/init.d/dbrecover start", if it is truly related to the password 
> > database. However, I never ran this as it appeared to eventually clear 
> > itself up the two times POP3 flaked-out on the new (two-day old) platform, 
> > but not before the POP3 issue was widely noticed.
> >
> > If xinetd is the issue, which I remember plenty of problems related to 
> > inet on heavily used Cobalts, shouldn't the Hosting edition use qpopper in 
> > standalone mode instead of xinetd? Or at least be compiled to be easily 
> > switched? I don't have gcc on the server, so this is not that simple. The 
> > default of xinetd.conf was maybe not best for a busy mail server, 
> > instances was 60 and cps was 25 30, and changed to UNLIMITED and 50 10, 
> > and will change instances to a more sane setting later.
> >
> > If qpopper is the issue and Dovecot is going to be eventually replaced, is 
> > this the RPM in the CentOS 4 base? Is there anything special needed to get 
> > this Dovecot RPM to work with the 'virtual' users and pwdb? Or is source 
> > and gcc needed? CentOS 4 has Dovecot or Cyrus-imapd, replacing the UW 
> > imapd from CentOS 3. I have no opinion on either of the options available 
> > in CentOS 4, except that Cyrus looks like it prefers virtual users (MySQL) 
> > instead of regular Linux users, so it might be easier to hook to pwdb.
> >
> > Finally, is pwdb optimized to work in high workload environments? I ask 
> > this because the previous platform had issues with POP3, and 9 times out 
> > of 10 I was running something to clean-up and repair the user database to 
> > fix the issue and not so much tweaking xinetd/pop3 settings... It is 
> > almost the same problem now, except the new platform appears to be able to 
> > recover by itself, well, eventually.
> >
> > The server (old and new) is 2.8GHz, 2GB (1GB for old server), 2 x 80GB 
> > SATA, and load has always been lower than 1.00. There are 800+ users, 
> > mainly business users so heaviest usage is 8AM-5PM, and I can see 50-80 
> > users per minute (and no, these are not all the same users every minute).
> >
> >
> >
> > Rusty
> >
> > -----Original Message-----
> > From: patricko [mailto:patricko (at mark) staff.singnet.com.sg]
> > Sent: Monday, March 06, 2006 10:02 PM
> > To: coba-e (at mark) bluequartz.org
> > Subject: [coba-e:04258] fyi: Re: Optimizing qpopper or POP3 alternative
> >
> > Hi,
> >
> >
> > Qpopper still Can Work with 1500++ users.
> >
> > But you need to Remove Xinetd configuration from qpopper.
> >
> > Basically, xinetd temporary stop connection after Threshold is reached.
> >
> >
> > Steps involved:
> >
> > 1) Recompile Qpopper without Xinetd
> > 2) Run with -s -R -S
> >
> >
> >
> > Cheers
> > patrick
> >
> >
> >
> >
> > On Mon, 6 Mar 2006 11:08:46 -0600
> > "Chris McGinnis" <chrism (at mark) t3wireless.com> wrote:
> >
> >> What version of Dovecot did you install and how did you install it?
> >> The qpopper thing is getting way out of hand on a production server
> >> and I need to get it resolved ASAP.
> >>
> >>
> >> ----- Original Message -----
> >> From: ""Ing. Ernesto PñÓez Estñ×ez"" <info (at mark) ecualinux.com>
> >> To: <coba-e (at mark) bluequartz.org>
> >> Sent: Friday, March 03, 2006 1:01 PM
> >> Subject: [coba-e:04248] Re: Optimizing qpopper or POP3 alternative
> >>
> >>
> >> > -----BEGIN PGP SIGNED MESSAGE-----
> >> > Hash: SHA1
> >> >
> >> > I installed dovecot and was able to get rid of this problem. qpopper
> >> > was a bit slow... and dovecot solved that situation.
> >> >
> >> > epe
> >> >
> >> > Chris McGinnis wrote:
> >> >> I have setup a machine with NuOnce CentOS + Bluequartz.  I have
> >> >> migrated 100 virtual sites from a RaQ 550 and have run into problems 
> >> >> with qpopper.
> >> >>
> >> >> After a while there will be 50+ qpopper instances running and
> >> >> client connections will timeout saying:
> >> >> -ERR POP EOF or I/O Error
> >> >>
> >> >> Any recommendations on optimizing qpopper or possibly replacing
> >> >> qpopper with something else?  All of these sites came from a
> >> >> RaQ550, I would expect my new server to handle the load just fine.
> >> >>
> >> >> The specs on the machine are: 3.2Ghz, 2GB ram, SATA 200GB HDD
> >> >>
> >> >> -Chris
> >> >>
> >> >>
> >> >>
> >> >
> >> > - --
> >> > Ing. Ernesto PñÓez Estñ×ez
> >> > http://www.ecualinux.com
> >> > USA: + 1 404 795 0321
> >> > Ecuador: (02)3412402 - (09) 9246504
> >> > -----BEGIN PGP SIGNATURE-----
> >> > Version: GnuPG v1.2.6 (GNU/Linux)
> >> > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
> >> >
> >> > iD8DBQFECJJ68sSWs7RP4EMRAklmAKCPyAYygp/fvhM/f1PjPfSHslASPQCg8Ee2
> >> > 2JSUL8a9P8zJHQh8lspYk+4=
> >> > =AyJ/
> >> > -----END PGP SIGNATURE-----
> >> >
> >> >
> >>
> >>
> >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.1.375 / Virus Database: 268.1.2/274 - Release Date: 3/3/2006
> >
> >
> >
> >
> > 
> 
> 
>