On Monday 13 March 2006 21:44, Chris McGinnis wrote:
> In the testing repository there's a version of poprelayd that I believe
> works with Dovecot.
>
> I have recompiled qpopper and then finally migrated to Dovecot. I am still
> seeing issues with the POP3 service getting overwhelmed. Both qpopper and
> Dovecot timeout under heavy loads. The machine is an Intel 3.2Ghz, 2GB
> RAM, SATA HDD. There are around 1000 users. I don't know what else to do
> other than move some of the users to another box. If anyone has any
> suggestions I'd be glad to hear them.
Hmmm, if running as a "daemon" process, then you will have to find something
"faster" or more effecient.
If running as an inetd (xinetd) process, then all Linux Kernels will "timeout"
a process if it gets spawned (started) more than 200 times per minute (the
default process limit). You can modify this with the older/original inetd by
chainging the line that calls pop3 in the /etc/inetd.conf file to read
something like:
ORIGINAL: (from an RAQ4)
>pop-3 stream tcp nowait root /usr/sbin/tcpd in.qpopper -R
MODIFIED:
>pop-3 stream tcp nowait.400 root /usr/sbin/tcpd in.qpopper -R
Note the dot 400 appended to the nowait column. This instructs inetd to allow
400 processes per minute (vice the 200 default). On a few servers I have had
to change this to 500, but use caution and don't just pick a "big" number.
Things you do on one side can affect other things and you don't want qpopper
using enough memory to starve the kernel or other processes...
Under xinetd, I believe the parameter to add is the "instances" parameter to
the /etc/xinetd.d/pop3 for qpopper. Believe it is defaulted to 80 instances
running per minute so it can probably safely be updated to 160 to 200 without
severe effect...
--
Larry Smith
SysAd ECSIS.NET
sysad (at mark) ecsis.net