Juju should warn if it detects conflicting MTU settings

[Chris Gregan]

We recently ran into an issue that was difficult to triage, but ended up being a mismatch in MTU settings between the vlan and the services deployed on that vlan. It would be very useful if Juju would throw up a flashing red light if it detects that the MTU settings on a deployment it is attempting to handle are mismatched.

See bug https://bugs.launchpad.net/juju/+bug/1733592 for additional details

[Tim Penhey (thumper)]

This is a very interesting thought.

A key question would be "where and how?"

What whould the error be attached to, and how would we present it to the user in a reasonalbe way.

Happy to chat to speed up ideas.

[Chris Gregan (cgregan)]

I was thinking on the status screen. Seems to be the one place everyone
looks. I am open to suggestions too.

On Fri, Nov 24, 2017 at 2:07 AM, Tim Penhey <email address hidden>
wrote:

> This is a very interesting thought.
>
> A key question would be "where and how?"
>
> What whould the error be attached to, and how would we present it to the
> user in a reasonalbe way.
>
> Happy to chat to speed up ideas.
>
> ** Changed in: juju
> Status: New => Incomplete
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1733944
>
> Title:
> Juju should warn if it detects conflicting MTU settings
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/juju/+bug/1733944/+subscriptions
>

--
Chris Gregan
Quality Assurance Manager
Field Engineering/CPE
<email address hidden>

[John A Meinel (jameinel)]

We've had some discussions in the past about something like "juju alerts"
which would be a place to put issues with your controller that don't fit
about a model. (Example, something wrong with one of the workers inside the
controller.) I think the discussions around it would be to point you to
alerts if there were any pending. But we haven't really fleshed that out
yet.

On Mon, Nov 27, 2017 at 5:42 PM, Chris Gregan <email address hidden>
wrote:

> I was thinking on the status screen. Seems to be the one place everyone
> looks. I am open to suggestions too.
>
> On Fri, Nov 24, 2017 at 2:07 AM, Tim Penhey <email address hidden>
> wrote:
>
> > This is a very interesting thought.
> >
> > A key question would be "where and how?"
> >
> > What whould the error be attached to, and how would we present it to the
> > user in a reasonalbe way.
> >
> > Happy to chat to speed up ideas.
> >
> > ** Changed in: juju
> > Status: New => Incomplete
> >
> > --
> > You received this bug notification because you are subscribed to the bug
> > report.
> > https://bugs.launchpad.net/bugs/1733944
> >
> > Title:
> > Juju should warn if it detects conflicting MTU settings
> >
> > To manage notifications about this bug go to:
> > https://bugs.launchpad.net/juju/+bug/1733944/+subscriptions
> >
>
>
> --
> Chris Gregan
> Quality Assurance Manager
> Field Engineering/CPE
> <email address hidden>
>
> --
> You received this bug notification because you are subscribed to juju.
> Matching subscriptions: juju bugs
> https://bugs.launchpad.net/bugs/1733944
>
> Title:
> Juju should warn if it detects conflicting MTU settings
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/juju/+bug/1733944/+subscriptions
>

[Ante Karamatić (ivoks)]

So, problem is that MTU on physical machine was not matched with an MTU on LXD. Juju has view of both of these, the physical machine's MTU and MTU for LXD. In fact, it configures LXD itself.

I'm not sure how useful is for a tool to tell me it did something wrong. So, better behaviour would be to set MTU correctly or exit as soon as possible. It shouldn't deploy a machine with a broken MTU, particulary because it knows its broken.

Does that make sense?

[Christian Reis (kiko)]

See https://bugs.launchpad.net/maas/+bug/1733945 for the MAAS counterpart.

[Anastasia (anastasia-macmood)]

It looks like the best way is to follow suggestion in comment # 4 and exit as soon as possible.

[Canonical Juju QA Bot (juju-qa-bot)]

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.