@Jason,

Are these tests with archive grub or patched grub?

On Tue, Feb 6, 2018 at 11:39 AM, Jason Hobbs <jason.ho...@canonical.com>
wrote:

> Andres,
>
> I ran the test with VMs limited to 9 of 20 cores (cut the core limit
> in half for VMs).  The first time range from this dump is with the
> cores at their normal limit (18).
>
> As you can see, the behavior didn't change much from one set to the
> other.  Both sets had instances where grub started doing retries,
> although in neither case did it take very long.
>
> http://paste.ubuntu.com/26530737/
>
> So it seems that changing the CPU limits for the VMs doesn't change
> the results drastically, which lines up with the data showing CPU
> utilization never gets over 50%.
>
> Jason
>
>
> On Mon, Feb 5, 2018 at 10:19 PM, Andres Rodriguez
> <andres...@ubuntu-pe.org> wrote:
> >>
> >>
> >> > That being said, because CPU load doesn't show high we are making the
> >> > *assumption* that it is not impacting MAAS, but again, this is an
> >> > assumption. Making the requested change for having at least 4 CPUs
> >> (ideally
> >> > 6) would allow us to determining what are the effects and see whether
> >> > there's any difference on behavior and would help identify what other
> >> > issues.
> >> >
> >> > Without having the comparison then we are making it more difficult to
> >> > isolate the problem.
> >>
> >> To improve performance the typical pattern is 1) identify the
> >> bottleneck 2) eliminate that as the bottleneck 3) repeat.
> >>
> >> We have not identified CPU as a bottleneck.  The top data says it is
> >> not!
> >>
> >
> > Jason,
> >
> > That doesn't change the fact that we are requesting tests to be run with
> > different CPU configuration for VM's, so we can make a *comparison* and
> see
> > if there is any material difference or none at all with the current
> > conditions. While I agree with you that the data /seems/ to show that
> there
> > is not issue with CPU, that doesn't change the fact that we don't have
> any
> > data to compare with, as there could still be an impact even if it is
> > minimum.
> >
> > Without the data, we cannot certainly assert that there's no issue caused
> > by CPU usage because we don't have a reference or point of comparison. So
> > while all fingers seem to be pointing to storage, It strongly believe it
> is
> > worth gathering the data now and fully discard.
> >
> > If this is something that your environment is unable to do, I would
> > appreciate that you clarify that instead of asserting that there's no
> > performance impact in MAAS due to CPU usage, when we don't really know
> for
> > sure (e.g. we don't know if MAAS behaves differently with less CPU usage
> in
> > the current conditions, and that's data worth gathering to be able to
> > better support you in the future).
> >
> > --
> > Andres Rodriguez (RoAkSoAx)
> > Ubuntu Server Developer
> > MSc. Telecom & Networking
> > Systems Engineer
> >
> > --
> > You received this bug notification because you are subscribed to the bug
> > report.
> > https://bugs.launchpad.net/bugs/1743249
> >
> > Title:
> >   Failed Deployment after timeout trying to retrieve grub cfg
> >
> > Status in MAAS:
> >   New
> > Status in grub2 package in Ubuntu:
> >   In Progress
> >
> > Bug description:
> >   A node failed to deploy after it failed to retrieve a grub.cfg from
> >   MAAS due to a timeout.  In the logs, it's clear that the server tried
> >   to retrieve the grub cfg many times, over about 30 seconds:
> >
> >   http://paste.ubuntu.com/26387256/
> >
> >   We see the same thing for other hosts around the same time:
> >
> >   http://paste.ubuntu.com/26387262/
> >
> >   It seems like MAAS is taking way too long to respond to these
> >   requests.
> >
> >   This is very similar to bug 1724677, which was happening pre-
> >   metldown/spectre. The only difference is we don't see "[critical] TFTP
> >   back-end failed" in the logs anymore.
> >
> >   I connected to the console on this system and it had errors about
> >   timing out retrieving the grub-cfg, then it had an error message along
> >   the lines of "error not an ip" and then "double free".  After I
> >   connected but before I could get a screenshot the system rebooted and
> >   was directed by maas to power off, which it did successfully after
> >   booting to linux.
> >
> >   Full logs are available here:
> >   https://10.245.162.101/artifacts/14a34b5a-9321-4d1a-b2fa-
> >   ed277a020e7c/cpe_cloud_395/infra-logs.tar
> >
> >   This is with 2.3.0-6434-gd354690-0ubuntu1~16.04.1.
> >
> > To manage notifications about this bug go to:
> > https://bugs.launchpad.net/maas/+bug/1743249/+subscriptions
>
> --
> You received this bug notification because you are subscribed to MAAS.
> https://bugs.launchpad.net/bugs/1743249
>
> Title:
>   Failed Deployment after timeout trying to retrieve grub cfg
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/maas/+bug/1743249/+subscriptions
>
> Launchpad-Notification-Type: bug
> Launchpad-Bug: product=maas; milestone=2.4.x; status=New;
> importance=Undecided; assignee=None;
> Launchpad-Bug: distribution=ubuntu; sourcepackage=grub2; component=main;
> status=In Progress; importance=Medium; assignee=mathieu...@gmail.com;
> Launchpad-Bug-Tags: cdo-qa cdo-qa-blocker foundations-engine patch
> Launchpad-Bug-Information-Type: Public
> Launchpad-Bug-Private: no
> Launchpad-Bug-Security-Vulnerability: no
> Launchpad-Bug-Commenters: andreserl blake-rouse cgregan jason-hobbs
> mpontillo vorlon
> Launchpad-Bug-Reporter: Jason Hobbs (jason-hobbs)
> Launchpad-Bug-Modifier: Jason Hobbs (jason-hobbs)
> Launchpad-Message-Rationale: Subscriber (MAAS)
> Launchpad-Message-For: andreserl
>


-- 
Andres Rodriguez (RoAkSoAx)
Ubuntu Server Developer
MSc. Telecom & Networking
Systems Engineer

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1743249

Title:
  Failed Deployment after timeout trying to retrieve grub cfg

To manage notifications about this bug go to:
https://bugs.launchpad.net/maas/+bug/1743249/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to