Re: [hybi] WebSocket -76 is incompatible with HTTP reverse proxies

"Thomson, Martin" <Martin.Thomson@andrew.com> Wed, 07 July 2010 22:38 UTC

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From: "Thomson, Martin" <Martin.Thomson@andrew.com>
To: Greg Wilkins <gregw@webtide.com>
Date: Thu, 08 Jul 2010 06:40:20 +0800
Thread-Topic: [hybi] WebSocket -76 is incompatible with HTTP reverse proxies
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Cc: "hybi@ietf.org" <hybi@ietf.org>
Subject: Re: [hybi] WebSocket -76 is incompatible with HTTP reverse proxies
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That's reasonable.

The alternative is to have Content-Length set to the length of the extra stuff - make the extra handshake stuff part of the message body.  That pulls it up into the HTTP.  That only applies on the request - the response to a successful handshake can do anything it likes once the HTTP part is out of the way.

> -----Original Message-----
> From: Greg Wilkins [mailto:gregw@webtide.com]
> Sent: Thursday, 8 July 2010 1:02 AM
> To: Thomson, Martin
> Cc: Roberto Peon; Willy Tarreau; hybi@ietf.org
> Subject: Re: [hybi] WebSocket -76 is incompatible with HTTP reverse
> proxies
> 
> Martin,
> 
> You are correct that it is not an extra round trip.  But I do not
> think it is a good solution to send a complete HTTP message PLUS extra
> stuff in the request.
> 
> If the handshake is legal HTTP, the server should be able to rejects
> the websocket upgrade without closing the connection.  This would
> allow the connection to remain in the browsers pool of connections and
> avoid an extra round trip to establish another connection if the
> application falls back to non-websocket transports.
> 
> Sending extra stuff after the response is OK.
> 
> cheers
> 
> 
> 
> 
> 
> 
> 
> On 7 July 2010 15:23, Thomson, Martin <Martin.Thomson@andrew.com>
> wrote:
> >
> >> Content-length: 0 also makes sense but it means that the nonce will
> >> be sent *after* the handshake, which means we'd have a second
> >> round-trip.
> >
> > The round-trip thing is a fallacy.  Just as you can pipeline
> requests, so can you send extra handshakey parts after the headers.
> >
> > Solution:  The handshake includes a complete HTTP message, PLUS extra
> stuff.  All of this is sent at once, but the HTTP stuff stops half way.
> >
> > This is only true if the extra stuff is dependent on information from
> the peer, which is not the case in this scenario.
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> >