haproxy BADREQ errors

Question

I am seeing errors similar to the following in my haproxy logs:

Jul 18 17:05:30 localhost haproxy[8247]: 188.223.50.7:51940 [18/Jul/2011:17:05:24.339] http_proxy_ads http_proxy_ads/<NOSRV> -1/-1/-1/-1/6001 408 212 - - cR-- 100/89/0/0/0 0/0 "<BADREQ>" 
Jul 18 17:05:30 localhost haproxy[8247]: 188.223.50.7:51943 [18/Jul/2011:17:05:24.341] http_proxy_ads http_proxy_ads/<NOSRV> -1/-1/-1/-1/6000 408 212 - - cR-- 99/88/0/0/0 0/0 "<BADREQ>" 

etc...

So far I have tried to increase the client timeout (to 6 seconds from 3), and increase the http request buffer from 16k to 32k. The errors still appear.

Can anyone give me guidance on what to look for here?

Answer 1

=> The client never completed its request, which was aborted by the
   time-out ("c---") after 5s, while the proxy was waiting for the request
   headers ("-R--").  Nothing was sent to any server, but the proxy could
   send a 408 return code to the client.

Solution: change "timeout http-request" to 20s ore more instead your 5s.

Answer 2

BADREQ just means that the client sent a bad request; in HTTP mode, it could mean that the client stuffed up, and there's nothing you can do about it. To see what the exact error was, connect to the stats socket (using socat) and run show errors. Chances are it's someone trying to run an exploit on some other webserver, so you can ignore it.