I am running haproxy in front of a asp.net application. The application has
been running happily for a while!
Recently I have been running into very hard to trace errors. I could use
some guidance to further analyse the situation.
What happens is that one of my clients can predictably generate an error in
my application where the server is unable to process a POST result due to
some unknown error in the POST data. The error is an asp.net index out of
range error in a generic part of a binding operation. My code is then not
yet in control of the situation. In other words, nothing I can do about it
in my source code.
Unfortunately I am unable to reproduce the situation from my office.
I went to visit the client yesterday and found he has a very complex and
slow network infrastructure. The issue is not due to old browsers and the
issue can be reproduced by using internet explorer or Chrome.
I analysed the haproxy log files and see the following actions that run
without errors, this is from my office with high speed internet access:
[30/Oct/2014:20:32:39 +0100] bk_ws06/iis05 8309/0/1/350/8661 200 79576 - -
---- 23/23/0/0/0 0/0 {www.customera.nl|} POST
/clientb/nl-nl/bestellingen/vooriemandanders.aspx HTTP/1.1
[30/Oct/2014:20:32:48 +0100] bk_ws06/iis05 1562/0/1/13548/19205 200 3455532
- - ---- 31/31/0/1/0 0/0 {www.customera.nl|} POST
/clientb/nl-nl/bestellingen/vooriemandanders.aspx HTTP/1.1
But the client experiences the following with a slow connection:
[30/Oct/2014:11:51:39 +0100] bk_ws06/iis05 6916/0/0/633/7551 200 74996 - -
---- 39/39/0/0/0 0/0 {www.customera.nl|} POST
/clientb/nl-nl/bestellingen/vooriemandanders.aspx HTTP/1.1
[30/Oct/2014:11:51:47 +0100] bk_ws06/iis05 4421/0/0/7226/45463 200 3944897 -
- ---- 33/33/0/0/0 0/0 {www.customera.nl|} POST
/clientb/nl-nl/bestellingen/vooriemandanders.aspx HTTP/1.1
[30/Oct/2014:11:52:32 +0100] bk_ws06/iis05 141644/0/1/17201/160926 302 635 -
- ---- 52/52/0/0/0 0/0 {www.customera.nl|} POST
/clientb/nl-nl/bestellingen/vooriemandanders.aspx HTTP/1.1
[30/Oct/2014:11:55:13 +0100] bk_ws06/iis05 0/0/0/93/93 200 28992 - - ----
52/52/0/1/0 0/0 {www.customera.nl|} GET
/Default.aspx?tabid=14471&error=An%20unexpected%20error%20has%20occurred&con
tent=0 HTTP/1.1
What really surprises me is the third line showing a 302 http code which I
do not expect.
In my haproxy config I set the following "defaults":
timeout connect 5s
timeout client 240s
timeout server 240s
option http-server-close
retries 3
I tried to use fiddler at my office to simulate a slow connections but I
cannot reproduce the situation.
What can I do?
Thanks in advance Evert
