Mailing List Archive: [neutron] heads up to long time ovs users...

The neutron team is finally removing the ovs-ofctl option.

https://review.openstack.org/#/c/599496/

The ovs-ofctl of_interface option wasn't default since Newton and was
deprecated in Pike.

So, if you are a long time ovs-agent user and upgrading to a new
coming release, you must switch from the ovs-ofctl implementation to
the native implementation and are affected by the following issue.

https://bugs.launchpad.net/neutron/+bug/1793354

The loss of communication mentioned in this bug report would be a few
seconds to a few minutes depending on the number of network
interfaces. It happens when an ovs-agent is restarted with the new
of_interface (so only once during the upgrade) and persists until the
network interfaces are set up.

Please speak up if you cannot tolerate this during upgrades.

IIUC, this bug is unfixable and I'd like to move forward as
maintaining two of_interface implementation is a burden for the
neutron team.

--
IWAMOTO Toshihiro

_______________________________________________
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OpenStack-operators@lists.openstack.org
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The important point of this notice is that packet drops will happen when
switching of_interface option from ovs-ofctl (which was the default value
in the old releases) to native (which is the current default ).

Once neutron drops the option, if deployers use the legacy value
"ovs-ofctl", they will hit some packet losses when upgrading neutron to
Stein.

We have no actual data on large deployments so far and don't know how this
change impacts real deployments.

Your feedback would be really appreciated.

Best regards,
Akihiro Motoki (irc: amotoki)

2018?9?21?(?) 10:37 IWAMOTO Toshihiro <iwamoto@valinux.co.jp>:

> The neutron team is finally removing the ovs-ofctl option.
>
> https://review.openstack.org/#/c/599496/
>
> The ovs-ofctl of_interface option wasn't default since Newton and was
> deprecated in Pike.
>
> So, if you are a long time ovs-agent user and upgrading to a new
> coming release, you must switch from the ovs-ofctl implementation to
> the native implementation and are affected by the following issue.
>
> https://bugs.launchpad.net/neutron/+bug/1793354
>
> The loss of communication mentioned in this bug report would be a few
> seconds to a few minutes depending on the number of network
> interfaces. It happens when an ovs-agent is restarted with the new
> of_interface (so only once during the upgrade) and persists until the
> network interfaces are set up.
>
> Please speak up if you cannot tolerate this during upgrades.
>
> IIUC, this bug is unfixable and I'd like to move forward as
> maintaining two of_interface implementation is a burden for the
> neutron team.
>
> --
> IWAMOTO Toshihiro
>
>
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