Re: [hybi] Experiment comparing Upgrade and CONNECT handshakes

[Greg Wilkins <[e-mail]>]

On 1 December 2010 20:10, John Tamplin <[e-mail]> wrote:
> On Wed, Dec 1, 2010 at 2:01 PM, Greg Wilkins <[e-mail]> wrote:
>> As proposed, the Hello frames do not cost an extra round trip.
>
> Unless I misunderstood your proposal, doesn't the server have to wait
> for the client's Hello reply before it can send any messages?  That
> seems like it adds one RTT (not two, as it would be if the first Hello
> wasn't piggy-backed with the server response).'

The server can send messages as soon as it has sent it's Hello.


> I agree the Hello frames are useful in this case.  However, how often
> is this case present, and is getting a WebSocket-layer timeout rather
> than app-layer (which in most cases will have to be present anyway)
> worth the price for all the other cases?  I don't have any numbers for
> it (do you?), but my gut feeling is it is low.

I agree that Hellos may be less useful with CONNECT.  But we have to
do something about the current handshakes unframed bytes and space
encoded nonces.  If we leave the unframed bytes as they are with
CONNECT, then we will probably still have the identified issue of an
intermediary that does not forward the bytes and the server hanging
while it tries to read them.


> Except that depending on what we switch to, those things you want
> removed aren't present at all, such as in Adam's proposals.

Adam's complete proposal has other aspects to it that are not as well
accepted as trying CONNECT.

If we do agree that CONNECT is better than Upgrade, that is not a
reason to completely adopt the first proposal that uses CONNECT
without questioning each of it's elements.

The handshake is in such a mess because we accepted a big bundle of
changes after only agreeing one aspect of them. We have now spent
months talking about the removal of the additional "features" that
crept in with that batch.

> So, moving them somewhere else doesn't seem like an incremental step but
> rather wasted effort.

Incremental changes are always wasted effort if you are 100% sure you
know all the increments in advance.
The whole point of incremental changes is that you can re-evaluate
along the way and perhaps revert some changes made earlier when
considered in the light of subsequent changes.