Re: [PATCH v3 0/8] Hiding refs

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Wed, Feb 6, 2013 at 8:17 PM, Junio C Hamano <gitster@pobox.com> wrote:

Maybe this should be split up into a different thread, but:

> The upload-pack-2 service sits on a port different from today's
> [...].

I think there's a simpler way to do this, which is that:

 * New clients supporting v2 of the protocol send some piece of data
   that would break old servers.

 * If that fails the new client goes "oh jeeze, I guess it's an old
   server", and try again with the old protocol.

 * The client then saves a date (or the version the server gave us)
   indicating that it tried the new protocol on that remote, tries
   again sometime later.

We already covered in previous discussions how this would be simpler
with the HTTP protocol, since you could just send an extra header
inviting the server to speak the new protocol.

But for the other transports we can just try the new protocol and
retry with the old one as a fallback if it doesn't work. That'll allow
us to gracefully migrate without needing to change the git:// port.

Besides, I think the vast majority of users are using Git via http://
or ssh://, where we can't just change the port, but even so making
people change the port when we could handle this more gracefully would
be a big PITA. Adding new firewall holes is often a big bureaucratic
nightmare in some organizations.