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
