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From: "Frank Filz" <ffilzlnx@mindspring.com>
To: "'bfields'" <bfields@fieldses.org>, "'Daire Byrne'" <daire@dneg.com>
Cc: "'Trond Myklebust'" <trondmy@hammerspace.com>,
	"'linux-cachefs'" <linux-cachefs@redhat.com>,
	"'linux-nfs'" <linux-nfs@vger.kernel.org>
Subject: RE: Adventures in NFS re-exporting
Date: Tue, 24 Nov 2020 14:15:57 -0800	[thread overview]
Message-ID: <0fc201d6c2af$62b039f0$2810add0$@mindspring.com> (raw)
In-Reply-To: <20201124211522.GC7173@fieldses.org>

> On Tue, Nov 24, 2020 at 08:35:06PM +0000, Daire Byrne wrote:
> > Sometimes I have seen clusters of 16 GETATTRs for the same file on the
> > wire with nothing else inbetween. So if the re-export server is the
> > only "client" writing these files to the originating server, why do we
> > need to do so many repeat GETATTR calls when using nconnect>1? And why
> > are the COMMIT calls required when the writes are coming via nfsd but
> > not from userspace on the re-export server? Is that due to some sort
> > of memory pressure or locking?
> >
> > I picked the NFSv3 originating server case because my head starts to
> > hurt tracking the equivalent packets, stateids and compound calls with
> > NFSv4. But I think it's mostly the same for NFSv4. The writes through
> > the re-export server lead to lots of COMMITs and (double) GETATTRs but
> > using nconnect>1 at least doesn't seem to make it any worse like it
> > does for NFSv3.
> >
> > But maybe you actually want all the extra COMMITs to help better
> > guarantee your writes when putting a re-export server in the way?
> > Perhaps all of this is by design...
> 
> Maybe that's close-to-open combined with the server's tendency to
open/close
> on every IO operation?  (Though the file cache should have helped with
that, I
> thought; as would using version >=4.0 on the final
> client.)
> 
> Might be interesting to know whether the nocto mount option makes a
> difference.  (So, add "nocto" to the mount options for the NFS mount that
> you're re-exporting on the re-export server.)
> 
> By the way I made a start at a list of issues at
> 
> 	http://wiki.linux-nfs.org/wiki/index.php/NFS_re-export
> 
> but I was a little vague on which of your issues remained and didn't take
much
> time over it.
> 
> (If you want an account on that wiki BTW I seem to recall you just have to
ask
> Trond (for anti-spam reasons).)

How much conversation about re-export has been had at the wider NFS
community level? I have an interest because Ganesha  supports re-export via
the PROXY_V3 and PROXY_V4 FSALs. We currently don't have a data cache though
there has been discussion of such, we do have attribute and dirent caches.

Looking over the wiki page, I have considered being able to specify a
re-export of a Ganesha export without encapsulating handles. Ganesha
encapsulates the export_fs handle in a way that could be coordinated between
the original server and the re-export so they would both effectively have
the same encapsulation layer.

I'd love to see some re-export best practices shared among server
implementations, and also what we can do to improve things when two server
implementations are interoperating via re-export.

Frank


  reply	other threads:[~2020-11-25  1:54 UTC|newest]

Thread overview: 129+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-07 17:31 Adventures in NFS re-exporting Daire Byrne
2020-09-08  9:40 ` Mkrtchyan, Tigran
2020-09-08 11:06   ` Daire Byrne
2020-09-15 17:21 ` J. Bruce Fields
2020-09-15 19:59   ` Trond Myklebust
2020-09-16 16:01     ` Daire Byrne
2020-10-19 16:19       ` Daire Byrne
2020-10-19 17:53         ` [PATCH 0/2] Add NFSv3 emulation of the lookupp operation trondmy
2020-10-19 17:53           ` [PATCH 1/2] NFSv3: Refactor nfs3_proc_lookup() to split out the dentry trondmy
2020-10-19 17:53             ` [PATCH 2/2] NFSv3: Add emulation of the lookupp() operation trondmy
2020-10-19 20:05         ` [PATCH v2 0/2] Add NFSv3 emulation of the lookupp operation trondmy
2020-10-19 20:05           ` [PATCH v2 1/2] NFSv3: Refactor nfs3_proc_lookup() to split out the dentry trondmy
2020-10-19 20:05             ` [PATCH v2 2/2] NFSv3: Add emulation of the lookupp() operation trondmy
2020-10-20 18:37         ` [PATCH v3 0/3] Add NFSv3 emulation of the lookupp operation trondmy
2020-10-20 18:37           ` [PATCH v3 1/3] NFSv3: Refactor nfs3_proc_lookup() to split out the dentry trondmy
2020-10-20 18:37             ` [PATCH v3 2/3] NFSv3: Add emulation of the lookupp() operation trondmy
2020-10-20 18:37               ` [PATCH v3 3/3] NFSv4: Observe the NFS_MOUNT_SOFTREVAL flag in _nfs4_proc_lookupp trondmy
2020-10-21  9:33         ` Adventures in NFS re-exporting Daire Byrne
2020-11-09 16:02           ` bfields
2020-11-12 13:01             ` Daire Byrne
2020-11-12 13:57               ` bfields
2020-11-12 18:33                 ` Daire Byrne
2020-11-12 20:55                   ` bfields
2020-11-12 23:05                     ` Daire Byrne
2020-11-13 14:50                       ` bfields
2020-11-13 22:26                         ` bfields
2020-11-14 12:57                           ` Daire Byrne
2020-11-16 15:18                             ` bfields
2020-11-16 15:53                             ` bfields
2020-11-16 19:21                               ` Daire Byrne
2020-11-16 15:29                           ` Jeff Layton
2020-11-16 15:56                             ` bfields
2020-11-16 16:03                               ` Jeff Layton
2020-11-16 16:14                                 ` bfields
2020-11-16 16:38                                   ` Jeff Layton
2020-11-16 19:03                                     ` bfields
2020-11-16 20:03                                       ` Jeff Layton
2020-11-17  3:16                                         ` bfields
2020-11-17  3:18                                           ` [PATCH 1/4] nfsd: move fill_{pre,post}_wcc to nfsfh.c J. Bruce Fields
2020-11-17  3:18                                             ` [PATCH 2/4] nfsd: pre/post attr is using wrong change attribute J. Bruce Fields
2020-11-17 12:34                                               ` Jeff Layton
2020-11-17 15:26                                                 ` J. Bruce Fields
2020-11-17 15:34                                                   ` Jeff Layton
2020-11-20 22:38                                                     ` J. Bruce Fields
2020-11-20 22:39                                                       ` [PATCH 1/8] nfsd: only call inode_query_iversion in the I_VERSION case J. Bruce Fields
2020-11-20 22:39                                                         ` [PATCH 2/8] nfsd: simplify nfsd4_change_info J. Bruce Fields
2020-11-20 22:39                                                         ` [PATCH 3/8] nfsd: minor nfsd4_change_attribute cleanup J. Bruce Fields
2020-11-21  0:34                                                           ` Jeff Layton
2020-11-20 22:39                                                         ` [PATCH 4/8] nfsd4: don't query change attribute in v2/v3 case J. Bruce Fields
2020-11-20 22:39                                                         ` [PATCH 5/8] nfs: use change attribute for NFS re-exports J. Bruce Fields
2020-11-20 22:39                                                         ` [PATCH 6/8] nfsd: move change attribute generation to filesystem J. Bruce Fields
2020-11-21  0:58                                                           ` Jeff Layton
2020-11-21  1:01                                                             ` J. Bruce Fields
2020-11-21 13:00                                                           ` Jeff Layton
2020-11-20 22:39                                                         ` [PATCH 7/8] nfsd: skip some unnecessary stats in the v4 case J. Bruce Fields
2020-11-20 22:39                                                         ` [PATCH 8/8] Revert "nfsd4: support change_attr_type attribute" J. Bruce Fields
2020-11-20 22:44                                                       ` [PATCH 2/4] nfsd: pre/post attr is using wrong change attribute J. Bruce Fields
2020-11-21  1:03                                                         ` Jeff Layton
2020-11-21 21:44                                                           ` Daire Byrne
2020-11-22  0:02                                                             ` bfields
2020-11-22  1:55                                                               ` Daire Byrne
2020-11-22  3:03                                                                 ` bfields
2020-11-23 20:07                                                                   ` Daire Byrne
2020-11-17 15:25                                               ` J. Bruce Fields
2020-11-17  3:18                                             ` [PATCH 3/4] nfs: don't mangle i_version on NFS J. Bruce Fields
2020-11-17 12:27                                               ` Jeff Layton
2020-11-17 14:14                                                 ` J. Bruce Fields
2020-11-17  3:18                                             ` [PATCH 4/4] nfs: support i_version in the NFSv4 case J. Bruce Fields
2020-11-17 12:34                                               ` Jeff Layton
2020-11-24 20:35               ` Adventures in NFS re-exporting Daire Byrne
2020-11-24 21:15                 ` bfields
2020-11-24 22:15                   ` Frank Filz [this message]
2020-11-25 14:47                     ` 'bfields'
2020-11-25 16:25                       ` Frank Filz
2020-11-25 19:03                         ` 'bfields'
2020-11-26  0:04                           ` Frank Filz
2020-11-25 17:14                   ` Daire Byrne
2020-11-25 19:31                     ` bfields
2020-12-03 12:20                     ` Daire Byrne
2020-12-03 18:51                       ` bfields
2020-12-03 20:27                         ` Trond Myklebust
2020-12-03 21:13                           ` bfields
2020-12-03 21:32                             ` Frank Filz
2020-12-03 21:34                             ` Trond Myklebust
2020-12-03 21:45                               ` Frank Filz
2020-12-03 21:57                                 ` Trond Myklebust
2020-12-03 22:04                                   ` bfields
2020-12-03 22:14                                     ` Trond Myklebust
2020-12-03 22:39                                       ` Frank Filz
2020-12-03 22:50                                         ` Trond Myklebust
2020-12-03 23:34                                           ` Frank Filz
2020-12-03 22:44                                       ` bfields
2020-12-03 21:54                               ` bfields
2020-12-03 22:45                               ` bfields
2020-12-03 22:53                                 ` Trond Myklebust
2020-12-03 23:16                                   ` bfields
2020-12-03 23:28                                     ` Frank Filz
2020-12-04  1:02                                     ` Trond Myklebust
2020-12-04  1:41                                       ` bfields
2020-12-04  2:27                                         ` Trond Myklebust
2020-09-17 16:01   ` Daire Byrne
2020-09-17 19:09     ` bfields
2020-09-17 20:23       ` Frank van der Linden
2020-09-17 21:57         ` bfields
2020-09-19 11:08           ` Daire Byrne
2020-09-22 16:43         ` Chuck Lever
2020-09-23 20:25           ` Daire Byrne
2020-09-23 21:01             ` Frank van der Linden
2020-09-26  9:00               ` Daire Byrne
2020-09-28 15:49                 ` Frank van der Linden
2020-09-28 16:08                   ` Chuck Lever
2020-09-28 17:42                     ` Frank van der Linden
2020-09-22 12:31 ` Daire Byrne
2020-09-22 13:52   ` Trond Myklebust
2020-09-23 12:40     ` J. Bruce Fields
2020-09-23 13:09       ` Trond Myklebust
2020-09-23 17:07         ` bfields
2020-09-30 19:30   ` [Linux-cachefs] " Jeff Layton
2020-10-01  0:09     ` Daire Byrne
2020-10-01 10:36       ` Jeff Layton
2020-10-01 12:38         ` Trond Myklebust
2020-10-01 16:39           ` Jeff Layton
2020-10-05 12:54         ` Daire Byrne
2020-10-13  9:59           ` Daire Byrne
2020-10-01 18:41     ` J. Bruce Fields
2020-10-01 19:24       ` Trond Myklebust
2020-10-01 19:26         ` bfields
2020-10-01 19:29           ` Trond Myklebust
2020-10-01 19:51             ` bfields

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