[Bug 5124] Parallelize the rsync run using multiple threads and/or connections

[L A Walsh]

On 10/11/2018 10:51 AM, just subscribed for rsync-qa from bugzilla via

rsync wrote:
> https://bugzilla.samba.org/show_bug.cgi?id=5124
>
> --- Comment #7 from Luiz Angelo Daros de Luca <luizluca at gmail.com> ---
> I also vote for this feature. Using multiple connections, rsync can use
> multiples internet connections at the same time.
>   
FWIW, one of the big changes that went into SMB 3 for Win10 was
adding the ability to do file transfers using more than one connection.

CIFS (and windows) have traditionally been limited to 1 connection that
everything was multiplexed over.

However, CIFS in write/reads from a client to a linux server can
easily get over 600MB/s writes, and ~275MB/s on reads.  The reason
it doesn't get more, is the cpu's start maxing out with processing
interrupts and packets.  I don't see rsync maxing out in cpu even
doing a local->local copy, but I haven't done benchmarks on the newer
versions of rsync, either.

That said, I don't think the slow down is such that it would greatly
benefit by multiple connections.  My local disk can do read/writes
to disk at around 1GB/s (for constant read/write).  I'd be more
convinced that parallel connections would benefit if there was
any benchmarking done to find out where slowdowns are happening,
but that's just my 2cents.  :-)