watcher.decision_engine.strategy.strategies.base

Source code for watcher.decision_engine.strategy.strategies.base

# -*- encoding: utf-8 -*-
# Copyright (c) 2015 b<>com
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
A :ref:`Strategy <strategy_definition>` is an algorithm implementation which is
able to find a :ref:`Solution <solution_definition>` for a given
:ref:`Goal <goal_definition>`.

There may be several potential strategies which are able to achieve the same
:ref:`Goal <goal_definition>`. This is why it is possible to configure which
specific :ref:`Strategy <strategy_definition>` should be used for each
:ref:`Goal <goal_definition>`.

Some strategies may provide better optimization results but may take more time
to find an optimal :ref:`Solution <solution_definition>`.

When a new :ref:`Goal <goal_definition>` is added to the Watcher configuration,
at least one default associated :ref:`Strategy <strategy_definition>` should be
provided as well.

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

import abc
import six

from oslo_config import cfg
from oslo_log import log
from oslo_utils import strutils

from watcher.common import clients
from watcher.common import context
from watcher.common import exception
from watcher.common.loader import loadable
from watcher.common import utils
from watcher.datasources import manager as ds_manager
from watcher.decision_engine.loading import default as loading
from watcher.decision_engine.model.collector import manager
from watcher.decision_engine.solution import default
from watcher.decision_engine.strategy.common import level

LOG = log.getLogger(__name__)
CONF = cfg.CONF


class StrategyEndpoint(object):
    def __init__(self, messaging):
        self._messaging = messaging

    def _collect_metrics(self, strategy, datasource):
        metrics = []
        if not datasource:
            return {'type': 'Metrics', 'state': metrics,
                    'mandatory': False, 'comment': ''}
        else:
            ds_metrics = datasource.list_metrics()
            if ds_metrics is None:
                raise exception.DataSourceNotAvailable(
                    datasource=datasource.NAME)
            else:
                for metric in strategy.DATASOURCE_METRICS:
                    original_metric_name = datasource.METRIC_MAP.get(metric)
                    if original_metric_name in ds_metrics:
                        metrics.append({original_metric_name: 'available'})
                    else:
                        metrics.append({original_metric_name: 'not available'})
        return {'type': 'Metrics', 'state': metrics,
                'mandatory': False, 'comment': ''}

    def _get_datasource_status(self, strategy, datasource):
        if not datasource:
            state = "Datasource is not presented for this strategy"
        else:
            state = "%s: %s" % (datasource.NAME,
                                datasource.check_availability())
        return {'type': 'Datasource',
                'state': state,
                'mandatory': True, 'comment': ''}

    def _get_cdm(self, strategy):
        models = []
        for model in ['compute_model', 'storage_model', 'baremetal_model']:
            try:
                getattr(strategy, model)
            except Exception:
                models.append({model: 'not available'})
            else:
                models.append({model: 'available'})
        return {'type': 'CDM', 'state': models,
                'mandatory': True, 'comment': ''}

    def get_strategy_info(self, context, strategy_name):
        strategy = loading.DefaultStrategyLoader().load(strategy_name)
        try:
            is_datasources = getattr(strategy.config, 'datasources', None)
            if is_datasources:
                datasource = getattr(strategy, 'datasource_backend')
            else:
                datasource = getattr(strategy, strategy.config.datasource)
        except (AttributeError, IndexError):
            datasource = []
        available_datasource = self._get_datasource_status(strategy,
                                                           datasource)
        available_metrics = self._collect_metrics(strategy, datasource)
        available_cdm = self._get_cdm(strategy)
        return [available_datasource, available_metrics, available_cdm]


[docs]@six.add_metaclass(abc.ABCMeta) class BaseStrategy(loadable.Loadable): """A base class for all the strategies A Strategy is an algorithm implementation which is able to find a Solution for a given Goal. """ DATASOURCE_METRICS = [] """Contains all metrics the strategy requires from a datasource to properly execute""" MIGRATION = "migrate"
[docs] def __init__(self, config, osc=None): """Constructor: the signature should be identical within the subclasses :param config: Configuration related to this plugin :type config: :py:class:`~.Struct` :param osc: An OpenStackClients instance :type osc: :py:class:`~.OpenStackClients` instance """ super(BaseStrategy, self).__init__(config) self.ctx = context.make_context() self._name = self.get_name() self._display_name = self.get_display_name() self._goal = self.get_goal() # default strategy level self._strategy_level = level.StrategyLevel.conservative self._cluster_state_collector = None # the solution given by the strategy self._solution = default.DefaultSolution(goal=self.goal, strategy=self) self._osc = osc self._collector_manager = None self._compute_model = None self._storage_model = None self._baremetal_model = None self._input_parameters = utils.Struct() self._audit_scope = None self._datasource_backend = None
[docs] @classmethod @abc.abstractmethod def get_name(cls): """The name of the strategy""" raise NotImplementedError()
[docs] @classmethod @abc.abstractmethod def get_display_name(cls): """The goal display name for the strategy""" raise NotImplementedError()
[docs] @classmethod @abc.abstractmethod def get_translatable_display_name(cls): """The translatable msgid of the strategy""" # Note(v-francoise): Defined here to be used as the translation key for # other services raise NotImplementedError()
[docs] @classmethod @abc.abstractmethod def get_goal_name(cls): """The goal name the strategy achieves""" raise NotImplementedError()
[docs] @classmethod def get_goal(cls): """The goal the strategy achieves""" goal_loader = loading.DefaultGoalLoader() return goal_loader.load(cls.get_goal_name())
[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 """ datasources_ops = list(ds_manager.DataSourceManager.metric_map.keys()) return [ cfg.ListOpt( "datasources", help="Datasources to use in order to query the needed metrics." " This option overrides the global preference." " options: {0}".format(datasources_ops), item_type=cfg.types.String(choices=datasources_ops), default=None) ]
[docs] @abc.abstractmethod def pre_execute(self): """Pre-execution phase This can be used to fetch some pre-requisites or data. """ raise NotImplementedError()
[docs] @abc.abstractmethod def do_execute(self): """Strategy execution phase This phase is where you should put the main logic of your strategy. """ raise NotImplementedError()
[docs] @abc.abstractmethod def post_execute(self): """Post-execution phase This can be used to compute the global efficacy """ raise NotImplementedError()
def _pre_execute(self): """Base Pre-execution phase This will perform basic pre execution operations most strategies should perform. """ LOG.info("Initializing " + self.get_display_name() + " Strategy") if not self.compute_model: raise exception.ClusterStateNotDefined() if self.compute_model.stale: raise exception.ClusterStateStale() LOG.debug(self.compute_model.to_string())
[docs] def execute(self): """Execute a strategy :return: A computed solution (via a placement algorithm) :rtype: :py:class:`~.BaseSolution` instance """ self.pre_execute() self.do_execute() self.post_execute() self.solution.compute_global_efficacy() return self.solution
@property def collector_manager(self): if self._collector_manager is None: self._collector_manager = manager.CollectorManager() return self._collector_manager @property def compute_model(self): """Cluster data model :returns: Cluster data model the strategy is executed on :rtype model: :py:class:`~.ModelRoot` instance """ if self._compute_model is None: collector = self.collector_manager.get_cluster_model_collector( 'compute', osc=self.osc) audit_scope_handler = collector.get_audit_scope_handler( audit_scope=self.audit_scope) self._compute_model = audit_scope_handler.get_scoped_model( collector.get_latest_cluster_data_model()) if not self._compute_model: raise exception.ClusterStateNotDefined() if self._compute_model.stale: raise exception.ClusterStateStale() return self._compute_model @property def storage_model(self): """Cluster data model :returns: Cluster data model the strategy is executed on :rtype model: :py:class:`~.ModelRoot` instance """ if self._storage_model is None: collector = self.collector_manager.get_cluster_model_collector( 'storage', osc=self.osc) audit_scope_handler = collector.get_audit_scope_handler( audit_scope=self.audit_scope) self._storage_model = audit_scope_handler.get_scoped_model( collector.get_latest_cluster_data_model()) if not self._storage_model: raise exception.ClusterStateNotDefined() if self._storage_model.stale: raise exception.ClusterStateStale() return self._storage_model @property def baremetal_model(self): """Cluster data model :returns: Cluster data model the strategy is executed on :rtype model: :py:class:`~.ModelRoot` instance """ if self._baremetal_model is None: collector = self.collector_manager.get_cluster_model_collector( 'baremetal', osc=self.osc) audit_scope_handler = collector.get_audit_scope_handler( audit_scope=self.audit_scope) self._baremetal_model = audit_scope_handler.get_scoped_model( collector.get_latest_cluster_data_model()) if not self._baremetal_model: raise exception.ClusterStateNotDefined() if self._baremetal_model.stale: raise exception.ClusterStateStale() return self._baremetal_model
[docs] @classmethod def get_schema(cls): """Defines a Schema that the input parameters shall comply to :return: A jsonschema format (mandatory default setting) :rtype: dict """ return {}
@property def datasource_backend(self): if not self._datasource_backend: # Load the global preferred datasources order but override it # if the strategy has a specific datasources config datasources = CONF.watcher_datasources if self.config.datasources: datasources = self.config self._datasource_backend = ds_manager.DataSourceManager( config=datasources, osc=self.osc ).get_backend(self.DATASOURCE_METRICS) return self._datasource_backend @property def input_parameters(self): return self._input_parameters @input_parameters.setter def input_parameters(self, p): self._input_parameters = p @property def osc(self): if not self._osc: self._osc = clients.OpenStackClients() return self._osc @property def solution(self): return self._solution @solution.setter def solution(self, s): self._solution = s @property def audit_scope(self): return self._audit_scope @audit_scope.setter def audit_scope(self, s): self._audit_scope = s @property def name(self): return self._name @property def display_name(self): return self._display_name @property def goal(self): return self._goal @property def strategy_level(self): return self._strategy_level @strategy_level.setter def strategy_level(self, s): self._strategy_level = s @property def state_collector(self): return self._cluster_state_collector @state_collector.setter def state_collector(self, s): self._cluster_state_collector = s def filter_instances_by_audit_tag(self, instances): if not self.config.check_optimize_metadata: return instances instances_to_migrate = [] for instance in instances: optimize = True if instance.metadata: try: optimize = strutils.bool_from_string( instance.metadata.get('optimize')) except ValueError: optimize = False if optimize: instances_to_migrate.append(instance) return instances_to_migrate def add_action_migrate(self, instance, migration_type, source_node, destination_node): parameters = {'migration_type': migration_type, 'source_node': source_node.uuid, 'destination_node': destination_node.uuid} self.solution.add_action(action_type=self.MIGRATION, resource_id=instance.uuid, input_parameters=parameters)
@six.add_metaclass(abc.ABCMeta) class DummyBaseStrategy(BaseStrategy): @classmethod def get_goal_name(cls): return "dummy" @classmethod def get_config_opts(cls): """Override base class config options as do not use datasource """ return [] @six.add_metaclass(abc.ABCMeta) class UnclassifiedStrategy(BaseStrategy): """This base class is used to ease the development of new strategies The goal defined within this strategy can be used to simplify the documentation explaining how to implement a new strategy plugin by omitting the need for the strategy developer to define a goal straight away. """ @classmethod def get_goal_name(cls): return "unclassified" @six.add_metaclass(abc.ABCMeta) class ServerConsolidationBaseStrategy(BaseStrategy): REASON_FOR_DISABLE = 'watcher_disabled' @classmethod def get_goal_name(cls): return "server_consolidation" @six.add_metaclass(abc.ABCMeta) class ThermalOptimizationBaseStrategy(BaseStrategy): @classmethod def get_goal_name(cls): return "thermal_optimization" @six.add_metaclass(abc.ABCMeta) class WorkloadStabilizationBaseStrategy(BaseStrategy): @classmethod def get_goal_name(cls): return "workload_balancing" @six.add_metaclass(abc.ABCMeta) class NoisyNeighborBaseStrategy(BaseStrategy): @classmethod def get_goal_name(cls): return "noisy_neighbor" @six.add_metaclass(abc.ABCMeta) class SavingEnergyBaseStrategy(BaseStrategy): @classmethod def get_goal_name(cls): return "saving_energy" @classmethod def get_config_opts(cls): """Override base class config options as do not use datasource """ return [] @six.add_metaclass(abc.ABCMeta) class ZoneMigrationBaseStrategy(BaseStrategy): @classmethod def get_goal_name(cls): return "hardware_maintenance" @classmethod def get_config_opts(cls): """Override base class config options as do not use datasource """ return [] @six.add_metaclass(abc.ABCMeta) class HostMaintenanceBaseStrategy(BaseStrategy): REASON_FOR_MAINTAINING = 'watcher_maintaining' @classmethod def get_goal_name(cls): return "cluster_maintaining" @classmethod def get_config_opts(cls): """Override base class config options as do not use datasource """ return []
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