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nova
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Merge "Fix and update compute schedulers config guide"

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Zuul 2018-02-16 20:04:41 +00:00 committed by Gerrit Code Review
parent 5b56bf6335 8be8d02aa7
commit e7725bffbd
2 changed files with 23 additions and 32 deletions
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53
doc/source/admin/configuration/schedulers.rst
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@ -13,12 +13,14 @@ Compute is configured with the following default scheduler options in the
.. code-block:: ini
scheduler_driver_task_period = 60
scheduler_driver = nova.scheduler.filter_scheduler.FilterScheduler
scheduler_available_filters = nova.scheduler.filters.all_filters
scheduler_default_filters = RetryFilter, AvailabilityZoneFilter, ComputeFilter, ComputeCapabilitiesFilter, ImagePropertiesFilter, ServerGroupAntiAffinityFilter, ServerGroupAffinityFilter
[scheduler]
driver = filter_scheduler
By default, the ``scheduler_driver`` is configured as a filter scheduler, as
[filter_scheduler]
available_filters = nova.scheduler.filters.all_filters
enabled_filters = RetryFilter, AvailabilityZoneFilter, ComputeFilter, ComputeCapabilitiesFilter, ImagePropertiesFilter, ServerGroupAntiAffinityFilter, ServerGroupAffinityFilter
By default, the scheduler ``driver`` is configured as a filter scheduler, as
described in the next section. In the default configuration, this scheduler
considers hosts that meet all the following criteria:
@ -39,29 +41,13 @@ considers hosts that meet all the following criteria:
* Are in a set of group hosts (if requested) (``ServerGroupAffinityFilter``).
The scheduler caches its list of available hosts; use the
``scheduler_driver_task_period`` option to specify how often the list is
updated.
.. note::
Do not configure ``service_down_time`` to be much smaller than
``scheduler_driver_task_period``; otherwise, hosts appear to be dead while
the host list is being cached.
For information about the volume scheduler, see the `Block Storage section
<https://docs.openstack.org/admin-guide/blockstorage-manage-volumes.html>`_ of
OpenStack Administrator Guide.
The scheduler chooses a new host when an instance is migrated.
When evacuating instances from a host, the scheduler service honors the target
host defined by the administrator on the :command:`nova evacuate` command. If
a target is not defined by the administrator, the scheduler determines the
target host. For information about instance evacuation, see `Evacuate instances
<https://docs.openstack.org/admin-guide/
compute-node-down.html#evacuate-instances>`_ section of the OpenStack
Administrator Guide.
target host. For information about instance evacuation, see
:ref:`Evacuate instances <node-down-evacuate-instances>`.
.. _compute-scheduler-filters:
@ -84,14 +70,15 @@ request, described in the :ref:`weights` section.
.. figure:: /figures/filteringWorkflow1.png
The ``scheduler_available_filters`` configuration option in ``nova.conf``
provides the Compute service with the list of the filters that are used by the
scheduler. The default setting specifies all of the filter that are included
with the Compute service:
The ``available_filters`` configuration option in ``nova.conf``
provides the Compute service with the list of the filters that are available
for use by the scheduler. The default setting specifies all of the filters that
are included with the Compute service:
.. code-block:: ini
scheduler_available_filters = nova.scheduler.filters.all_filters
[filter_scheduler]
available_filters = nova.scheduler.filters.all_filters
This configuration option can be specified multiple times. For example, if you
implemented your own custom filter in Python called ``myfilter.MyFilter`` and
@ -100,16 +87,18 @@ you wanted to use both the built-in filters and your custom filter, your
.. code-block:: ini
scheduler_available_filters = nova.scheduler.filters.all_filters
scheduler_available_filters = myfilter.MyFilter
[filter_scheduler]
available_filters = nova.scheduler.filters.all_filters
available_filters = myfilter.MyFilter
The ``scheduler_default_filters`` configuration option in ``nova.conf`` defines
The ``enabled_filters`` configuration option in ``nova.conf`` defines
the list of filters that are applied by the ``nova-scheduler`` service. The
default filters are:
.. code-block:: ini
scheduler_default_filters = RetryFilter, AvailabilityZoneFilter, ComputeCapabilitiesFilter, ImagePropertiesFilter, ServerGroupAntiAffinityFilter, ServerGroupAffinityFilter
[filter_scheduler]
enabled_filters = RetryFilter, AvailabilityZoneFilter, ComputeCapabilitiesFilter, ImagePropertiesFilter, ServerGroupAntiAffinityFilter, ServerGroupAffinityFilter
Compute filters
~~~~~~~~~~~~~~~

2
doc/source/admin/node-down.rst
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@ -5,6 +5,8 @@ Recover from a failed compute node
If you deploy Compute with a shared file system, you can use several methods to
quickly recover from a node failure. This section discusses manual recovery.
.. _node-down-evacuate-instances:
Evacuate instances
~~~~~~~~~~~~~~~~~~