[Bug 1743249] Re: Failed Deployment after timeout trying to retrieve grub cfg

[Jason Hobbs]

@Mike, you can see the stacked response behavior in
https://bugs.launchpad.net/maas/+bug/1743249/+attachment/5046952/+files/spearow-fall-back-to-default-amd64.pcap

You can tell packet 90573 is a response to the requests for
grub.cfg-<mac> because its destination port (25305) is the src port
the request for grub.cfg-<mac> was coming from (packets 2 through 38).

On Mon, Feb 5, 2018 at 6:11 PM, Mike Pontillo
<mike.pontillo at canonical.com> wrote:
> Steve, can you be more specific about which packet capture showed the
> "stacked OACK" behavior?
>
> I looked at a packet capture Andres pointed me to, and don't see the
> "stacked OACKs" you describe. Each TFTP transaction (per RFC 1350) is
> indicated by the (source port, dest port) tuple, and I see that MAAS
> correctly OACKs each individual transaction (per RFC 2347) - not the
> retry packets within the same transaction. Subsequently (in the same
> second, after the client ACKs the data packet) it re-requests the same
> file (which is the bug in grub that I understand is fixed), and then the
> client starts a new transaction and MAAS correctly issues another OACK.
>
> --
> 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

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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