yahoo-eng-team team mailing list archive

[Nikola Đipanov <ndipanov@xxxxxxxxxx>]

Public bug reported:

More in-depth discussion can be found here:

http://lists.openstack.org/pipermail/openstack-
dev/2015-February/056695.html

Basically - there is a number of filters that need to be re-run even if
we force a host. The reasons are two-fold. Placing some instances on
some hosts is an obvious mistake and should be disallowed (instances
with specific CPU pinning are an example), though this will be
eventually rejected by the host. Second reason is that claims logic on
compute hosts depends on limits being set by the filters, and if they
are not some of the oversubscription as well as more complex placement
logic will not work for the instance (see the following bug report as to
how it impacts NUMA placement logic
https://bugzilla.redhat.com/show_bug.cgi?id=1189906)

Overall completely bypassing the filters is not ideal.

** Affects: nova
     Importance: Low
     Assignee: Sylvain Bauza (sylvain-bauza)
         Status: Confirmed


** Tags: scheduler

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https://bugs.launchpad.net/bugs/1427772

Title:
  Instance that uses force-host still needs to run some filters

Status in OpenStack Compute (Nova):
  Confirmed

Bug description:
  More in-depth discussion can be found here:

  http://lists.openstack.org/pipermail/openstack-
  dev/2015-February/056695.html

  Basically - there is a number of filters that need to be re-run even
  if we force a host. The reasons are two-fold. Placing some instances
  on some hosts is an obvious mistake and should be disallowed
  (instances with specific CPU pinning are an example), though this will
  be eventually rejected by the host. Second reason is that claims logic
  on compute hosts depends on limits being set by the filters, and if
  they are not some of the oversubscription as well as more complex
  placement logic will not work for the instance (see the following bug
  report as to how it impacts NUMA placement logic
  https://bugzilla.redhat.com/show_bug.cgi?id=1189906)

  Overall completely bypassing the filters is not ideal.

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