openstack/nova
Code Issues Proposed changes

Information about DifferentHostFilter and SameHostFilter added.

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Change-Id: Ice5f03db5f3d24455c43af86bf5722b863cbe959
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Dina Belova 2012-04-09 16:59:45 +04:00
parent 21dbbaa386
commit c1e397b746
1 changed files with 13 additions and 0 deletions
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doc/source/devref/filter_scheduler.rst
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@ -42,6 +42,10 @@ There are some standard filter classes to use (:mod:`nova.scheduler.filters`):
enough available RAM.
* |SimpleCIDRAffinityFilter| - allows to put a new instance on a host within
the same IP block.
* |DifferentHostFilter| - allows to put the instance on a different host from a
set of instances.
* |SameHostFilter| - puts the instance on the same host as another instance in
a set of of instances.
Now we can focus on these standard filter classes in details. I will pass the
simplest ones, such as |AllHostsFilter|, |CoreFilter| and |RamFilter| are,
@ -87,6 +91,13 @@ images to run on the isolated hosts are also called isolated. This Scheduler
checks if `image_isolated` flag named in instance specifications is the same
that the host has.
|DifferentHostFilter| - its method `host_passes` returns `True` if host to
place instance on is different from all the hosts used by set of instances.
|SameHostFilter| does the opposite to what |DifferentHostFilter| does. So its
`host_passes` returns `True` if the host we want to place instance on is one
of the set of instances uses.
|SimpleCIDRAffinityFilter| looks at the subnet mask and investigates if
the network address of the current host is in the same sub network as it was
defined in the request.
@ -243,3 +254,5 @@ in :mod:`nova.tests.scheduler`.
.. |JsonFilter| replace:: :class:`JsonFilter <nova.scheduler.filters.json_filter.JsonFilter>`
.. |RamFilter| replace:: :class:`RamFilter <nova.scheduler.filters.ram_filter.RamFilter>`
.. |SimpleCIDRAffinityFilter| replace:: :class:`SimpleCIDRAffinityFilter <nova.scheduler.filters.affinity_filter.SimpleCIDRAffinityFilter>`
.. |DifferentHostFilter| replace:: :class:`DifferentHostFilter <nova.scheduler.filters.affinity_filter.DifferentHostFilter>`
.. |SameHostFilter| replace:: :class:`SameHostFilter <nova.scheduler.filters.affinity_filter.SameHostFilter>`