On Tue, Apr 05, 2011 at 04:31:38AM +0200, Cyril Bonté wrote:
> Hi Marcin,
>
> Le lundi 4 avril 2011 23:39:22, Marcin Gozdalik a écrit :
> > Hi
> >
> > I'm trying to put RTMPT (
> > http://en.wikipedia.org/wiki/Real_Time_Messaging_Protocol) traffic through
> > HAProxy. It seems to work well for a while but after that HAProxy replies
> > with 400 Bad request. I though it might be a problem with HTTP header
> > length (RTMPT sends on idle connections dummy headers thus inflating HTTP
> > header length), but I am not sure as there are several big headers which
> > HAProxy accepts and replies 200 OK. I would appreciate any help with
> > debugging or reconfiguring HAProxy to handle RTMPT.
> >
> > The client here is Flash Player, so I can't really control what it sends.
> > Proxying the same traffic via Apache mod_proxy works OK but I'd like to
> > separate my reverse proxy from backend Web servers.
> >
> > The capture is here: http://gozdal.com/rtmpt-400.pcap
>
> As you can see in the capture, idle requests duplicayes headers. Each request
> sends a longer list of headers. After some times, the request becomes longer
> than the haproxy buffer, which results in a 400 Bad Request. If it works with
>
> mod_proxy, it's more by chance.
>
> The bug comes from the flash player plugin :
> https://bugs.adobe.com/jira/browse/FP-4797
>
> It's not clear if it has been fixed in the last version.
>
> Do you need Layer 7 enabled in your configuration or "mode tcp" would be an
> acceptable workaround ?
Alternatively you can force haproxy to use larger buffers, but this will eat
more RAM. You can do that like this :
global
tune.bufsize 65536
tune.maxrewrite 1024
The defaults are 16k and 8k, meaning that "only" 16-8 = 8kB are used as the
max request size. With the setting above, you'll have 64k for each request,
which will consume 128kB of RAM per connection.
Anyway, this Flash bug will cause a big performance issue at some point,
because the clients really have to upload that many data, and this can
take a lot of time, especially in mobile environments, where uploading
64kB can take up to about 30 seconds in some cases.
Regards,
Willy
