[librsync-devel] Re: state of the rsync nation? (revisited 6/2003 from 11/2000)

jw schultz jw at pegasys.ws
Fri Jun 13 14:05:04 EST 2003

On Fri, Jun 13, 2003 at 01:25:06PM +1000, Martin Pool wrote:
> On 12 Jun 2003, jw schultz <jw at pegasys.ws> wrote:
> > Leave the communications protocol to the communications
> > layer.  You don't save anything by coding reordering and
> > retransmission at the packet level; that is infrastructure.
> > 
> > Connectionless is fine.  Lightweight sessions is better.  If
> > you lose a connection a restart is possible.  It is
> > preferable to not have to authenticate and negotiate
> > protocol versions and encryption with every message.
> > 
> > Think in terms of transactions.  Each transaction is atomic.
> > If a transaction doesn't complete you have the means to
> > roll-back and retry.  If a connection breaks between
> > transactions, or leaving a transaction incomplete, you start
> > a new connection and pick up where you left off.
> I agree with all this.
> To extend on what jw says:
> I think it's fine to (if desired) negotiate SSL, authentication, and
> compression at the start of a connection.  They generally require
> multiple round trips and it would be wasteful to do them more
> frequently when per-connection is natural.
> On the other hand it would be nice if the client could pick up an
> interrupted transfer halfway through the tree, rather than needing to
> start from the beginning as rsync 2.x does. 

Mind you, that means making the server lightweight with the
client doing all the logic and a nearly stateless connection.
Much like my earlier post on this thread posited.

	J.W. Schultz            Pegasystems Technologies
	email address:		jw at pegasys.ws

		Remember Cernan and Schmitt

More information about the rsync mailing list