You may also want to check "ulimit -n" prior to running your server. It may default to 1024 on your distro, and if lighttpd doesn't automatically increase it for you, that could be your problem.
> -----Original Message----- > From: David Birdsong [mailto:david.birds...@gmail.com] > Sent: Wednesday, October 21, 2009 7:07 AM > To: John Lauro > Cc: haproxy > Subject: Re: slow tcp handshake > > On Wed, Oct 21, 2009 at 3:51 AM, John Lauro > <john.la...@covenanteyes.com> wrote: > > You mention loopback interface. You could be running out of port > numbers to > > for the connections. > > What's your /proc/sys/net/ipv4/ip_local_port_range? > cat /proc/sys/net/ipv4/ip_local_port_range > 32768 61000 > > > > > > > > What's netstat -s | grep -i list show on the server? > nothing at all, no list to match on that output > > > > > > > also, i've disabled tcp_sack with no effect > > > >> -----Original Message----- > >> From: David Birdsong [mailto:david.birds...@gmail.com] > >> Sent: Wednesday, October 21, 2009 6:36 AM > >> To: haproxy > >> Subject: slow tcp handshake > >> > >> This isn't haproxy related, but this list is so knowledgable on > >> network problems. > >> > >> I'm troubleshooting our slow webserver and I've drilled down to a > TCP > >> handshake taking up to 10 seconds. This handshake doesn't actually > >> really start until the client sends it's 3rd syn. The first 2 syn's > >> are completely ignored, the 3rd is ACKed a full 10 seconds after the > >> first syn is sent. After this, read times are fast. > >> > >> This happens over the loopback interface. > >> > >> Can an app get backed up in it's listen queue and affect some sort > of > >> syn queue, or will the kernel handle the handshake irrespective of > the > >> server's listen queue? > >> > >> I've searched all over the internets, and I'm plumb out of ideas. > >> > >> syn_cookies are disabled > >> ip_tables unloaded > >> /proc/sys/net/ipv4/tcp_max_syn_backlog was set to 1024 and active > >> connections to the server never rose above 960, so thought this may > be > >> it...but i doubled it and it had no affect > >> > >> > >> Fedora 8 2.6.26.8-57.fc8 > >> Web server is lighttpd > >> > >> No virus found in this incoming message. > >> Checked by AVG - www.avg.com > >> Version: 8.5.422 / Virus Database: 270.14.11/2430 - Release Date: > >> 10/20/09 18:42:00 > > > > > > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.422 / Virus Database: 270.14.11/2430 - Release Date: > 10/20/09 18:42:00
