From: "Daniel P. Berrangé" <berrange@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: quintela@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org,
kraxel@redhat.com, pabeni@redhat.com
Subject: Re: [RFC PATCH 0/5] mptcp support
Date: Mon, 12 Apr 2021 15:56:08 +0100 [thread overview]
Message-ID: <YHRfiHiR0D/vvbc2@redhat.com> (raw)
In-Reply-To: <YHReXk6Hv7qF0Oqz@work-vm>
On Mon, Apr 12, 2021 at 03:51:10PM +0100, Dr. David Alan Gilbert wrote:
> * Daniel P. Berrangé (berrange@redhat.com) wrote:
> > On Thu, Apr 08, 2021 at 08:11:54PM +0100, Dr. David Alan Gilbert (git) wrote:
> > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > >
> > > Hi,
> > > This RFC set adds support for multipath TCP (mptcp),
> > > in particular on the migration path - but should be extensible
> > > to other users.
> > >
> > > Multipath-tcp is a bit like bonding, but at L3; you can use
> > > it to handle failure, but can also use it to split traffic across
> > > multiple interfaces.
> > >
> > > Using a pair of 10Gb interfaces, I've managed to get 19Gbps
> > > (with the only tuning being using huge pages and turning the MTU up).
> > >
> > > It needs a bleeding-edge Linux kernel (in some older ones you get
> > > false accept messages for the subflows), and a C lib that has the
> > > constants defined (as current glibc does).
> > >
> > > To use it you just need to append ,mptcp to an address;
> > >
> > > -incoming tcp:0:4444,mptcp
> > > migrate -d tcp:192.168.11.20:4444,mptcp
> >
> > What happens if you only enable mptcp flag on one side of the
> > stream (whether client or server), does it degrade to boring
> > old single path TCP, or does it result in an error ?
>
> I've just tested this and it matches what pabeni said; it seems to just
> fall back.
>
> > > I had a quick go at trying NBD as well, but I think it needs
> > > some work with the parsing of NBD addresses.
> >
> > In theory this is applicable to anywhere that we use sockets.
> > Anywhere that is configured with the QAPI SocketAddress /
> > SocketAddressLegacy type will get it for free AFAICT.
>
> That was my hope.
>
> > Anywhere that is configured via QemuOpts will need an enhancement.
> >
> > IOW, I would think NBD already works if you configure NBD via
> > QMP with nbd-server-start, or block-export-add. qemu-nbd will
> > need cli options added.
> >
> > The block layer clients for NBD, Gluster, Sheepdog and SSH also
> > all get it for free when configured va QMP, or -blockdev AFAICT
>
> Have you got some examples via QMP?
> I'd failed trying -drive if=virtio,file=nbd://192.168.11.20:3333,mptcp=on/zero
I never remember the mapping to blockdev QAPI schema, especially
when using legacy filename syntax with the URI.
Try instead
-blockdev driver=nbd,host=192.168.11.20,port=3333,mptcp=on,id=disk0backend
-device virtio-blk,drive=disk0backend,id=disk0
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
next prev parent reply other threads:[~2021-04-12 14:57 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-08 19:11 [RFC PATCH 0/5] mptcp support Dr. David Alan Gilbert (git)
2021-04-08 19:11 ` [RFC PATCH 1/5] channel-socket: Only set CLOEXEC if we have space for fds Dr. David Alan Gilbert (git)
2021-04-09 9:03 ` Daniel P. Berrangé
2021-04-08 19:11 ` [RFC PATCH 2/5] io/net-listener: Call the notifier during finalize Dr. David Alan Gilbert (git)
2021-04-09 9:06 ` Daniel P. Berrangé
2021-04-08 19:11 ` [RFC PATCH 3/5] migration: Add cleanup hook for inwards migration Dr. David Alan Gilbert (git)
2021-04-09 9:10 ` Daniel P. Berrangé
2021-04-08 19:11 ` [RFC PATCH 4/5] migration/socket: Close the listener at the end Dr. David Alan Gilbert (git)
2021-04-09 9:10 ` Daniel P. Berrangé
2021-04-09 9:20 ` Paolo Abeni
2021-04-08 19:11 ` [RFC PATCH 5/5] sockets: Support multipath TCP Dr. David Alan Gilbert (git)
2021-04-09 9:22 ` Daniel P. Berrangé
2021-04-10 9:03 ` Markus Armbruster
2021-04-12 15:42 ` Dr. David Alan Gilbert
2021-04-09 9:34 ` [RFC PATCH 0/5] mptcp support Daniel P. Berrangé
2021-04-09 9:42 ` Daniel P. Berrangé
2021-04-09 9:55 ` Paolo Abeni
2021-04-12 14:46 ` Dr. David Alan Gilbert
2021-04-09 9:47 ` Paolo Abeni
2021-04-12 14:51 ` Dr. David Alan Gilbert
2021-04-12 14:56 ` Daniel P. Berrangé [this message]
2021-04-14 18:49 ` Dr. David Alan Gilbert
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YHRfiHiR0D/vvbc2@redhat.com \
--to=berrange@redhat.com \
--cc=armbru@redhat.com \
--cc=dgilbert@redhat.com \
--cc=kraxel@redhat.com \
--cc=pabeni@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=quintela@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).