From: "Michael S. Tsirkin" <mst@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
Juan Quintela <quintela@redhat.com>,
Jason Wang <jasowang@redhat.com>,
qemu-devel@nongnu.org,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v2 01/27] migration: Network Failover can't work with a paused guest
Date: Thu, 3 Dec 2020 07:13:53 -0500 [thread overview]
Message-ID: <20201203071148-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20201203120614.GF2952498@redhat.com>
On Thu, Dec 03, 2020 at 12:06:14PM +0000, Daniel P. Berrangé wrote:
> > > It isn't really about the admin. It is about countless existing mgmt apps
> > > that expect migration will always succeed if the VM is paused. The mgmt
> > > apps triggering the migraiton is not neccessarily the same as the app
> > > which introduced the use of NIC failover in the config.
> > >
> > > eg in OpenStack Nova provides the VM config, but there are completely
> > > separate apps that are built todo automation on top of Nova which
> > > this is liable to break. There's no human admin there to diagnose
> > > this and re-try with unpause, as all the logic is in the apps.
> > >
> > >
> > > Regards,
> > > Daniel
> >
> > So let's say pause fails. Won't this break these theoretical apps?
>
> Yes, they are broken in a way that can now actually be seen, as opposed
> to just hanging forever in migration.
Right but there are countless apps out there, and they are all broken,
maybe not too hard to debug if one knows where to look, but still ...
And again only true for pause then migrate, migrate then pause is still
broken, and if we fix it by failing pause then no one knows whether apps
are prepared to handle a failure in the pause command, previously if
used correctly it would never fail I think ...
--
MST
next prev parent reply other threads:[~2020-12-03 12:14 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-18 8:37 [PATCH v2 00/27] Virtio net failover fixes Juan Quintela
2020-11-18 8:37 ` [PATCH v2 01/27] migration: Network Failover can't work with a paused guest Juan Quintela
2020-11-25 12:05 ` Dr. David Alan Gilbert
2020-12-02 10:13 ` Michael S. Tsirkin
2020-12-02 10:27 ` Daniel P. Berrangé
2020-12-02 10:31 ` Michael S. Tsirkin
2020-12-02 10:33 ` Michael S. Tsirkin
2020-12-02 10:51 ` Juan Quintela
2020-12-02 10:55 ` Daniel P. Berrangé
2020-12-02 11:19 ` Michael S. Tsirkin
2020-12-02 11:26 ` Daniel P. Berrangé
2020-12-02 11:37 ` Michael S. Tsirkin
2020-12-02 12:01 ` Daniel P. Berrangé
2020-12-03 11:21 ` Michael S. Tsirkin
2020-12-03 11:32 ` Daniel P. Berrangé
2020-12-03 11:40 ` Michael S. Tsirkin
2020-12-03 11:43 ` Dr. David Alan Gilbert
2020-12-03 12:02 ` Michael S. Tsirkin
2020-12-03 12:04 ` Dr. David Alan Gilbert
2020-12-03 12:11 ` Michael S. Tsirkin
2020-12-03 12:16 ` Daniel P. Berrangé
2020-12-08 18:48 ` Michael S. Tsirkin
2020-12-03 11:45 ` Daniel P. Berrangé
2020-12-03 12:01 ` Michael S. Tsirkin
2020-12-03 12:06 ` Daniel P. Berrangé
2020-12-03 12:13 ` Michael S. Tsirkin [this message]
2020-12-08 18:32 ` Michael S. Tsirkin
2020-12-02 10:34 ` Daniel P. Berrangé
2020-11-18 8:37 ` [PATCH v2 02/27] failover: fix indentantion Juan Quintela
2020-11-18 8:37 ` [PATCH v2 03/27] failover: Use always atomics for primary_should_be_hidden Juan Quintela
2020-11-18 8:37 ` [PATCH v2 04/27] failover: primary bus is only used once, and where it is set Juan Quintela
2020-11-18 8:37 ` [PATCH v2 05/27] failover: Remove unused parameter Juan Quintela
2020-11-18 8:37 ` [PATCH v2 06/27] failover: Remove external partially_hotplugged property Juan Quintela
2020-11-18 8:37 ` [PATCH v2 07/27] failover: qdev_device_add() returns err or dev set Juan Quintela
2020-11-18 8:37 ` [PATCH v2 08/27] failover: Rename bool to failover_primary_hidden Juan Quintela
2020-11-18 8:37 ` [PATCH v2 09/27] failover: g_strcmp0() knows how to handle NULL Juan Quintela
2020-11-18 8:37 ` [PATCH v2 10/27] failover: Remove primary_device_opts Juan Quintela
2020-11-18 8:37 ` [PATCH v2 11/27] failover: remove standby_id variable Juan Quintela
2020-11-18 8:37 ` [PATCH v2 12/27] failover: Remove primary_device_dict Juan Quintela
2020-11-18 8:37 ` [PATCH v2 13/27] failover: Remove memory leak Juan Quintela
2020-11-18 8:37 ` [PATCH v2 14/27] failover: simplify virtio_net_find_primary() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 15/27] failover: should_be_hidden() should take a bool Juan Quintela
2020-11-18 8:37 ` [PATCH v2 16/27] failover: Rename function to hide_device() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 17/27] failover: virtio_net_connect_failover_devices() does nothing Juan Quintela
2020-11-18 8:37 ` [PATCH v2 18/27] failover: Rename to failover_find_primary_device() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 19/27] failover: simplify qdev_device_add() failover case Juan Quintela
2020-11-18 8:37 ` [PATCH v2 20/27] failover: simplify qdev_device_add() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 21/27] failover: make sure that id always exist Juan Quintela
2020-11-18 8:37 ` [PATCH v2 22/27] failover: remove failover_find_primary_device() error parameter Juan Quintela
2020-11-18 8:37 ` [PATCH v2 23/27] failover: split failover_find_primary_device_id() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 24/27] failover: We don't need to cache primary_device_id anymore Juan Quintela
2020-11-18 8:37 ` [PATCH v2 25/27] failover: Caller of this two functions already have primary_dev Juan Quintela
2020-11-18 8:37 ` [PATCH v2 26/27] failover: simplify failover_unplug_primary Juan Quintela
2020-11-18 8:37 ` [PATCH v2 27/27] failover: Remove primary_dev member Juan Quintela
2020-11-18 8:53 ` [PATCH v2 00/27] Virtio net failover fixes Michael S. Tsirkin
2020-12-02 10:16 ` Juan Quintela
2020-12-02 10:30 ` Michael S. Tsirkin
2020-12-02 9:55 ` Michael S. Tsirkin
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=20201203071148-mutt-send-email-mst@kernel.org \
--to=mst@redhat.com \
--cc=berrange@redhat.com \
--cc=dgilbert@redhat.com \
--cc=ehabkost@redhat.com \
--cc=jasowang@redhat.com \
--cc=pbonzini@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).