- From: Robert Collins <robertc@robertcollins.net>
- Date: Fri, 21 Nov 2014 21:44:47 +1300
- To: Yutaka Hirano <yhirano@google.com>
- Cc: Andy Green <andy@warmcat.com>, Amos Jeffries <squid3@treenet.co.nz>, HTTP Working Group <ietf-http-wg@w3.org>
On 21 November 2014 20:03, Yutaka Hirano <yhirano@google.com> wrote: > > I don't like the idea of using the existing DATA frame. > > 1. An intermediary must flush data when it sees an end of message (FIN). But intermediaries won't be buffering: they'll be forwarding as soon as they can, since h2 is being established from the get-go as an interactive protocol. > IIUC we don't have such flag in the plain http2 (we had END_SEGMENT but it > is gone). So "just move opaque DATA payloads around" is not enough. Why not? Any ws ignorant h2 proxy that holds buffers for indeterminate periods because e.g. it wants to virus scan uploads/downloads is just as likely to a) reject unknown frames or b) inspect and scan ws frames. I don't see how we prevent that by using a custom frame. > 2. With explicit negotiation, I know that all peers in the communication > path understand ws-over-http2 perfectly and there is no chance to The proposed negotiation in the draft I saw didn't guarantee that (see my comments in this thread) because options isn't graph-capable: an intermediary that is capable advertises its capability, not the capability of peers on the other side of it, and no replacement negotiation has been proposed that I've seen. > misunderstand DATA in http2 and DATA in ws2, in theoretically. In reality, > that is not true. The history of WebSocket is the history of battles with > mis-implemented proxies (Note that the native WebSocket has the explicit > negotiation but proxies modify payloads without understanding it). I would > like to reduce the possibility of such confusion. WebSockets' HTTP/1.1 upgrade hack was a clever way to avoid a new port for a new protocol layered on top of 20 years of proxy evolution. We're not *at all* in the same situation now, and I think we should bear that in mind. -Rob -- Robert Collins <rbtcollins@hp.com> Distinguished Technologist HP Converged Cloud
Received on Friday, 21 November 2014 08:45:17 UTC