From: Trond Myklebust <trondmy@hammerspace.com>
To: "chuck.lever@oracle.com" <chuck.lever@oracle.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"aglo@umich.edu" <aglo@umich.edu>,
"Anna.Schumaker@netapp.com" <Anna.Schumaker@netapp.com>,
"neilb@suse.com" <neilb@suse.com>
Subject: Re: [PATCH 0/9] Multiple network connections for a single NFS mount.
Date: Tue, 11 Jun 2019 16:41:15 +0000 [thread overview]
Message-ID: <266475174966dd473670d9fc9f6a6d6af3d87d44.camel@hammerspace.com> (raw)
In-Reply-To: <35A94418-7DE0-4656-90B4-5A0183BA371C@oracle.com>
On Tue, 2019-06-11 at 11:35 -0400, Chuck Lever wrote:
> > On Jun 11, 2019, at 11:20 AM, Trond Myklebust <
> > trondmy@hammerspace.com> wrote:
> >
> > On Tue, 2019-06-11 at 10:51 -0400, Chuck Lever wrote:
> >
> > > If maxconn is a hint, when does the client open additional
> > > connections?
> >
> > As I've already stated, that functionality is not yet available.
> > When
> > it is, it will be under the control of a userspace daemon that can
> > decide on a policy in accordance with a set of user specified
> > requirements.
>
> Then why do we need a mount option at all?
>
For one thing, it allows people to play with this until we have a fully
automated solution. The fact that people are actually pulling down
these patches, forward porting them and trying them out would indicate
that there is interest in doing so.
Secondly, if your policy is 'I just want n connections' because that
fits your workload requirements (e.g. because said workload is both
latency sensitive and bursty), then a daemon solution would be
unnecessary, and may be error prone.
A mount option is helpful in this case, because you can perform the
setup through the normal fstab or autofs config file configuration
route. It also make sense if you have a nfsroot setup.
Finally, even if you do want to have a daemon manage your transport,
configuration, you do want a mechanism to help it reach an equilibrium
state quickly. Connections take time to bring up and tear down because
performance measurements take time to build up sufficient statistical
precision. Furthermore, doing so comes with a number of hidden costs,
e.g.: chewing up privileged port numbers by putting them in a TIME_WAIT
state. If you know that a given server is always subject to heavy
traffic, then initialising the number of connections appropriately has
value.
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com
next prev parent reply other threads:[~2019-06-11 16:41 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-30 0:41 [PATCH 0/9] Multiple network connections for a single NFS mount NeilBrown
2019-05-30 0:41 ` [PATCH 2/9] SUNRPC: Allow creation of RPC clients with multiple connections NeilBrown
2019-05-30 0:41 ` [PATCH 9/9] NFS: Allow multiple connections to a NFSv2 or NFSv3 server NeilBrown
2019-05-30 0:41 ` [PATCH 4/9] SUNRPC: enhance rpc_clnt_show_stats() to report on all xprts NeilBrown
2019-05-30 0:41 ` [PATCH 5/9] SUNRPC: add links for all client xprts to debugfs NeilBrown
2019-05-30 0:41 ` [PATCH 3/9] NFS: send state management on a single connection NeilBrown
2019-07-23 18:11 ` Schumaker, Anna
2019-07-23 22:54 ` NeilBrown
2019-07-31 2:05 ` [PATCH] NFS: add flags arg to nfs4_call_sync_sequence() NeilBrown
2019-05-30 0:41 ` [PATCH 8/9] pNFS: Allow multiple connections to the DS NeilBrown
2019-05-30 0:41 ` [PATCH 1/9] SUNRPC: Add basic load balancing to the transport switch NeilBrown
2019-05-30 0:41 ` [PATCH 7/9] NFSv4: Allow multiple connections to NFSv4.x servers NeilBrown
2019-05-30 0:41 ` [PATCH 6/9] NFS: Add a mount option to specify number of TCP connections to use NeilBrown
2019-05-30 17:05 ` [PATCH 0/9] Multiple network connections for a single NFS mount Tom Talpey
2019-05-30 17:20 ` Olga Kornievskaia
2019-05-30 17:41 ` Tom Talpey
2019-05-30 18:41 ` Olga Kornievskaia
2019-05-31 1:45 ` Tom Talpey
2019-05-30 22:38 ` NeilBrown
2019-05-31 1:48 ` Tom Talpey
2019-05-31 2:31 ` NeilBrown
2019-05-31 12:39 ` Tom Talpey
2019-05-30 23:53 ` Rick Macklem
2019-05-31 0:15 ` J. Bruce Fields
2019-05-31 1:01 ` NeilBrown
2019-05-31 2:20 ` Rick Macklem
2019-05-31 12:36 ` Tom Talpey
2019-05-31 13:33 ` Trond Myklebust
2019-05-30 17:56 ` Chuck Lever
2019-05-30 18:59 ` Olga Kornievskaia
2019-05-30 22:56 ` NeilBrown
2019-05-31 13:46 ` Chuck Lever
2019-05-31 15:38 ` J. Bruce Fields
2019-06-11 1:09 ` NeilBrown
2019-06-11 14:51 ` Chuck Lever
2019-06-11 15:05 ` Tom Talpey
2019-06-11 15:20 ` Trond Myklebust
2019-06-11 15:35 ` Chuck Lever
2019-06-11 16:41 ` Trond Myklebust [this message]
2019-06-11 17:32 ` Chuck Lever
2019-06-11 17:44 ` Trond Myklebust
2019-06-12 12:34 ` Steve Dickson
2019-06-12 12:47 ` Trond Myklebust
2019-06-12 13:10 ` Trond Myklebust
2019-06-11 15:34 ` Olga Kornievskaia
2019-06-11 17:46 ` Chuck Lever
2019-06-11 19:13 ` Olga Kornievskaia
2019-06-11 20:02 ` Tom Talpey
2019-06-11 20:09 ` Chuck Lever
2019-06-11 21:10 ` Olga Kornievskaia
2019-06-11 21:35 ` Tom Talpey
2019-06-11 22:55 ` NeilBrown
2019-06-12 12:55 ` Tom Talpey
2019-06-11 23:02 ` NeilBrown
2019-06-11 23:21 ` NeilBrown
2019-06-12 12:52 ` Tom Talpey
2019-06-11 23:42 ` NeilBrown
2019-06-12 12:39 ` Steve Dickson
2019-06-12 17:36 ` Chuck Lever
2019-06-12 23:03 ` NeilBrown
2019-06-13 16:13 ` Chuck Lever
2019-06-12 1:49 ` NeilBrown
2019-06-12 18:32 ` Chuck Lever
2019-06-12 23:37 ` NeilBrown
2019-06-13 16:27 ` Chuck Lever
2019-05-31 0:24 ` J. Bruce Fields
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