yahoo-eng-team team mailing list archive

[sean mooney <2083858@xxxxxxxxxxxxxxxxxx>]

Public bug reported:

downstream we had a bug report where live migration was failing on the
az filter after a customer renamed an az.

https://bugzilla.redhat.com/show_bug.cgi?id=2303395

nova does not support renaming AZs in general, or moving hosts with
instance between AZs

5 years ago as part of https://bugs.launchpad.net/nova/+bug/1378904 we made the API reject renmaes
when instance were on hosts
https://github.com/openstack/nova/commit/8e19ef4173906da0b7c761da4de0728a2fd71e24

we have since closed another edgecase with
https://github.com/openstack/nova/commit/3c0eadae0b9ec48586087ea6c0c4e9176f0aa3bc

in both case we missed the fact that if an instance was pinned to an az
and then shelved it wont be considered as "on a host" so the safety
checks we added for updating the az metadata or adding/removing hosts
form an az does not account for shelved instances.

if a shelved instance is pinned to a host or az and you update the host
membership or update the az name or delete the az then it is possible to
unshleve the instance but the request spec will refer to the new
deleted/renamed az

it is only possible to unshelve today on master because we have removed
the az filter and when using placement the host aggregate az will not
have changed its uuid even if the az name has changes.

we have 2 potinetlay issue that we should fix.

when updating an az name we should check if its refenced in any request
spec for any non deleted instance.

when adding or removing a host from a host aggrate(with az metadata) we
should check if a request spec refers to the host and if it does is the
az in the request spec compatible.

this but is prmiarly for the first case as i was able to repodce that
with horizon.

the second case is speculation that i bleive could happen and we shoudl consider that when fixing.
either provide it can happen and address it in this bug or as a separate one or note that it is blocked
for some other reasons or otherwise out scope.

** Affects: nova
     Importance: Medium
         Status: Triaged


** Tags: availability-zones placement

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https://bugs.launchpad.net/bugs/2083858

Title:
  nova allows AZ's to be renamed if instances are shelved

Status in OpenStack Compute (nova):
  Triaged

Bug description:
  downstream we had a bug report where live migration was failing on the
  az filter after a customer renamed an az.

  https://bugzilla.redhat.com/show_bug.cgi?id=2303395

  nova does not support renaming AZs in general, or moving hosts with
  instance between AZs

  5 years ago as part of https://bugs.launchpad.net/nova/+bug/1378904 we made the API reject renmaes
  when instance were on hosts
  https://github.com/openstack/nova/commit/8e19ef4173906da0b7c761da4de0728a2fd71e24

  we have since closed another edgecase with
  https://github.com/openstack/nova/commit/3c0eadae0b9ec48586087ea6c0c4e9176f0aa3bc

  in both case we missed the fact that if an instance was pinned to an
  az and then shelved it wont be considered as "on a host" so the safety
  checks we added for updating the az metadata or adding/removing hosts
  form an az does not account for shelved instances.

  if a shelved instance is pinned to a host or az and you update the
  host membership or update the az name or delete the az then it is
  possible to unshleve the instance but the request spec will refer to
  the new deleted/renamed az

  it is only possible to unshelve today on master because we have
  removed the az filter and when using placement the host aggregate az
  will not have changed its uuid even if the az name has changes.

  we have 2 potinetlay issue that we should fix.

  when updating an az name we should check if its refenced in any
  request spec for any non deleted instance.

  when adding or removing a host from a host aggrate(with az metadata)
  we should check if a request spec refers to the host and if it does is
  the az in the request spec compatible.

  this but is prmiarly for the first case as i was able to repodce that
  with horizon.

  the second case is speculation that i bleive could happen and we shoudl consider that when fixing.
  either provide it can happen and address it in this bug or as a separate one or note that it is blocked
  for some other reasons or otherwise out scope.

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