backends periodically rendered DEAD

[Gergely CZUCZY]

Hello,

I'm testing pound at the moment, and running paralelly around 15-18
apache benchmarks for a session-tracking test.

However pound keeps on losing the backends periodically and it
restores them a few seconds later they come back, and go back
to DEAD again.

It's a FreeBSD 6.2-p6. While the backends are marked as DEAD
I'm unable to reach them from a browser (say, elinks) directly.

FreeBSD lvs1.in.publishing.hu 6.2-RELEASE-p6 FreeBSD 6.2-RELEASE-p6 #1: Tue Jul 24 08:07:07 UTC 2007     toor at pointyhat.office:/usr/obj/usr/src/sys/LVS  i386

it's like this:
  0. http Listener 192.168.4.55:80 a
    0. Service active (0)
      0. Backend PF_INET 10.0.0.1:80 active (7 27125.432 sec) DEAD
    1. Service active (0)
      0. Backend PF_INET 10.0.0.1:80 active (7 32400.306 sec) DEAD
      1. Backend PF_INET 10.0.0.2:80 active (2 0.000 sec) DEAD
      2. Backend PF_INET 10.0.0.3:80 active (2 26940.430 sec) DEAD

I've got log messages like:
Jul 25 11:54:00 lvs1 pound: BackEnd 10.0.0.1:80 resurrect
Jul 25 11:54:00 lvs1 pound: BackEnd 10.0.0.3:80 resurrect
Jul 25 11:54:05 lvs1 pound: backend 10.0.0.1:80 connect: Operation not permitted
Jul 25 11:54:05 lvs1 last message repeated 27 times
Jul 25 11:54:05 lvs1 pound: no back-end "GET /phpinfo-lycos.html HTTP/1.0" from 192.168.4.21

Jul 25 11:53:31 lvs1 pound: error copy server cont: Broken pipe
Jul 25 11:53:34 lvs1 pound: backend 10.0.0.1:80 connect: Operation not permitted
Jul 25 11:53:34 lvs1 pound: backend 10.0.0.3:80 connect: Operation not permitted
Jul 25 11:53:34 lvs1 pound: backend 10.0.0.3:80 connect: Operation not permitted
Jul 25 11:54:27 lvs1 pound: error copy server cont: Broken pipe
Jul 25 11:54:27 lvs1 pound: error copy server cont: Connection reset by peer
Jul 25 11:54:27 lvs1 pound: error copy server cont: Broken pipe

And every combination of these with "no back-end" messages, but I've grepped
those out.

I'm using the pf(4) packet filter, but the log shows no dropped or denied packets.

To be honest, I don't really know where to begin with this issue. I've set the following
sysctls in order to have enough free ports in the range to connect to the web backends:
net.inet.ip.portrange.hilast: 65535
net.inet.ip.portrange.hifirst: 20000
net.inet.ip.portrange.last: 65535
net.inet.ip.portrange.first: 20000

I've googled around, but found nothing really relevant.

What data should I collect to be able to resolve this issue?

I've sent this mail both to the pound and the freebsd-net@ mailing list
because I don't really know where the issue really lies. Please take
this into account in the replies.

Sincerely,

Gergely Czuczy
mailto: gergely.czuczy at harmless.hu

-- 
Weenies test. Geniuses solve problems that arise.
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