Coda File System

Re: Coda-7.0.1 release

From: <u-x417_at_aetey.se>
Date: Sun, 6 Jan 2019 18:27:38 +0100
On Sat, Dec 22, 2018 at 03:46:26PM +0100, u-x417_at_aetey.se wrote:
> On Fri, Dec 21, 2018 at 11:47:27AM -0500, Jan Harkes wrote:
> > - codatunnel enabled by default
> > 
> >     Coda clients and servers now spawn a helper daemon that tunnels RPC2
> >     and SFTP through a TCP connection when possible. Because TCP
> >     connections provide reliable ordered delivery we can suppress
> >     certain retransmissions. Also masquerading firewalls are better at
> >     tracking state of TCP connections unlike UDP where the redirections
> >     are dropped after a short timeout, or in some cases when the first
> >     'reply' packet is observed.
> 
> I understand the advantages of backward compatibility, but are
> there any other compelling reasons to continue using UDP?

You probably did not have time for the discussion, at the Christmas
and New Year season. No problem and Happy New Year!

I checked the code and the comments there look like udp is not going
to be supported on the wire, unless "for backward compatibility with
legacy servers and clients". Good.

> Are you considering to eventually make rpc2 talk TCP directly or in
> some other way move to TCP-only communication without keeping an extra
> protocol layer?

Rpc2 behind the codatunnel seems to be the intended solution,
combining a well tested rpc implementation with the advantages of tcp
communications. As long as the overhead is small, this looks pretty
reasonable to me. Automatic backward compatibility is of course an
extra bonus.

Keep the work going!

Regards,
Rune
Received on 2019-01-06 12:28:45