Hi Guys,

I have been using haproxy in our company for months and have loved our experience. However we recently ran into a strange issue even though no changes happened on the haproxy side.

We are currently using haproxy 1.4.24 on Debian 7. Our backend consists of 6 Windows 2008 R2 servers running IIS 7.5. Strictly web servers for stateless applications and services round robin balanced.

I have been debugging with fiddler and usually requests work fine however once every few requests a page will hang and it appears that haproxy makes a connect to a backend server but the connection is lost before all the data is transferred.

Within Fiddler I receive a content length mismatch errors saying we should have downloaded 800 KB but only received 100KB. Our client and server connections are set to 10 min and the connect timeout is 5 seconds (increasing that had no effect).

I am able to recreate the issue but it is random and is not related to server load or network limitation as we don't have any other issues. I recreate by refreshing a page over and over until the issue arises.

Below find config...

Global config

global
log 127.0.0.1 local0
log 127.0.0.1 local1 notice
maxconn 100000
stats socket /var/run/haproxy.sock mode 0600 level admin user haproxy group haproxy daemon

Default config

defaults
log global
mode http
option httplog
option dontlognull
option redispatch
option forwardfor
option httpclose
option abortonclose
retries 1
timeout connect 5000
timeout client 50000
timeout server 50000

listen stats
#disabled
bind *:8888
stats enable
stats uri /haproxy?stats
stats realm Strictly\ Private
stats auth xxxxx:xxxxxx

frontend open *:80
timeout client 600000

default_backend web

backend web
timeout server 600000
balance roundrobin

server edrwebproawvc1 xxx.xxx.xxx.xxx:80 check
    server edrwebproawvd1 xxx.xxx.xxx.xxx:80 check
            server edrwebproawvc2 xxx.xxx.xxx.xxx:80 check
            server edrwebproawvd2 xxx.xxx.xxx.xxx:80 check
            server edrwebproawvc3 xxx.xxx.xxx.xxx:80 check
            server edrwebproawvd3 xxx.xxx.xxx.xxx:80 check

Any help you can point me to I would greatly appreciate it!