Re: unsharing tcp connections from different NFS mounts

[Trond Myklebust <trondmy@hammerspace.com>]

On Wed, 2020-10-07 at 14:04 -0400, Benjamin Coddington wrote:
> On 7 Oct 2020, at 12:44, Trond Myklebust wrote:
> > I did see Igor's claim that there is a QoS issue (which afaics
> > would
> > also affect NFSv3), but why do I care about QoS as a per-mountpoint
> > feature?
> 
> Because it's hard to do QoS without being able to classify the
> traffic on
> the network somehow.  The separate connection makes it a lot
> easier.  I see
> how that's - not our problem -, though.
> 
> The regular admin might find it surprising to tell their system to
> connect to a specific IP address at mount time, and it instead sends
> the
> mount's traffic elsewhere.
>
> Are you happy with the state of nconnect, or is there room for
> something
> more dynamic?
> 

I think there is room for improvement. We did say that we wanted to
eventually hand control over to a userspace policy daemon which should
be able to manage the number of connections based on demand and
networking conditions.
However as I already pointed out, NFSv4.1 also has congestion control
at the session level which may be playing a role here.

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com