Source code for watcher.decision_engine.planner.base

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# Copyright (c) 2015 b<>com
# Authors: Jean-Emile DARTOIS <>
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# you may not use this file except in compliance with the License.
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The :ref:`Watcher Planner <watcher_planner_definition>` is part of the
:ref:`Watcher Decision Engine <watcher_decision_engine_definition>`.

This module takes the set of :ref:`Actions <action_definition>` generated by a
:ref:`Strategy <strategy_definition>` and builds the design of a workflow which
defines how-to schedule in time those different
:ref:`Actions <action_definition>` and for each
:ref:`Action <action_definition>` what are the prerequisite conditions.

It is important to schedule :ref:`Actions <action_definition>` in time in order
to prevent overload of the :ref:`Cluster <cluster_definition>` while applying
the :ref:`Action Plan <action_plan_definition>`. For example, it is important
not to migrate too many instances at the same time in order to avoid a network
congestion which may decrease the :ref:`SLA <sla_definition>` for
:ref:`Customers <customer_definition>`.

It is also important to schedule :ref:`Actions <action_definition>` in order to
avoid security issues such as denial of service on core OpenStack services.

:ref:`Some default implementations are provided <watcher_planners>`, but it is
possible to :ref:`develop new implementations <implement_planner_plugin>`
which are dynamically loaded by Watcher at launch time.

See :doc:`../architecture` for more details on this component.

import abc
import six

from watcher.common.loader import loadable

[docs]@six.add_metaclass(abc.ABCMeta) class BasePlanner(loadable.Loadable):
[docs] @classmethod def get_config_opts(cls): """Defines the configuration options to be associated to this loadable :return: A list of configuration options relative to this Loadable :rtype: list of :class:`oslo_config.cfg.Opt` instances """ return []
[docs] @abc.abstractmethod def schedule(self, context, audit_uuid, solution): """The planner receives a solution to schedule :param solution: A solution provided by a strategy for scheduling :type solution: :py:class:`~.BaseSolution` subclass instance :param audit_uuid: the audit uuid :type audit_uuid: str :return: Action plan with an ordered sequence of actions such that all security, dependency, and performance requirements are met. :rtype: :py:class:`watcher.objects.ActionPlan` instance """ # example: directed acyclic graph raise NotImplementedError()