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17d1cf535a93931856d7ee8cf234dbd21e5a271d
watcher/watcher/decision_engine/strategy/strategies/noisy_neighbor.py
Douglas Viroel 17d1cf535a Deprecated Noisy Neighbor strategy 
Noisy neighbor strategy is a proof of concept strategy that was
built based on LLC metric, which is not available in Nova since
Victoria release[1].
This patch marks this strategy as deprecated, to be removed in
future releases.

[1] https://docs.openstack.org/releasenotes/nova/victoria.html#relnotes-22-0-0-unmaintained-victoria-upgrade-notes

Change-Id: I940b88555007312c76a86706bd44a38fbcf7701e
2025-05-12 15:44:39 -03:00

283 lines
9.9 KiB
Python
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# -*- encoding: utf-8 -*-
# Copyright (c) 2017 Intel Corp
#
# Authors: Prudhvi Rao Shedimbi <prudhvi.rao.shedimbi@intel.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.
#
from debtcollector import removals
from oslo_config import cfg
from oslo_log import log
import warnings
from watcher._i18n import _
from watcher.decision_engine.strategy.strategies import base
LOG = log.getLogger(__name__)
CONF = cfg.CONF
warnings.simplefilter('always')
@removals.removed_class("NoisyNeighbor", version="2025.2",
removal_version="2026.2")
class NoisyNeighbor(base.NoisyNeighborBaseStrategy):
"""Noisy Neighbor strategy using live migration
*Description*
This strategy can identify and migrate a Noisy Neighbor -
a low priority VM that negatively affects performance of
a high priority VM in terms of IPC by over utilizing
Last Level Cache.
*Requirements*
To enable LLC metric, latest Intel server with CMT support is required.
*Limitations*
This is a proof of concept that is not meant to be used in production
*Spec URL*
http://specs.openstack.org/openstack/watcher-specs/specs/pike/implemented/noisy_neighbor_strategy.html
"""
MIGRATION = "migrate"
DATASOURCE_METRICS = ['instance_l3_cache_usage']
DEFAULT_WATCHER_PRIORITY = 5
def __init__(self, config, osc=None):
super(NoisyNeighbor, self).__init__(config, osc)
self.meter_name = 'instance_l3_cache_usage'
@classmethod
def get_name(cls):
return "noisy_neighbor"
@classmethod
def get_display_name(cls):
return _("Noisy Neighbor")
@classmethod
def get_translatable_display_name(cls):
return "Noisy Neighbor"
@classmethod
def get_schema(cls):
# Mandatory default setting for each element
return {
"properties": {
"cache_threshold": {
"description": "Performance drop in L3_cache threshold "
"for migration",
"type": "number",
"default": 35.0
},
"period": {
"description": "Aggregate time period of "
"ceilometer and gnocchi",
"type": "number",
"default": 100.0
},
},
}
def get_current_and_previous_cache(self, instance):
try:
curr_cache = self.datasource_backend.get_instance_l3_cache_usage(
instance, self.meter_name, self.period,
'mean', granularity=300)
previous_cache = 2 * (
self.datasource_backend.get_instance_l3_cache_usage(
instance, self.meter_name, 2 * self.period,
'mean', granularity=300)) - curr_cache
except Exception as exc:
LOG.exception(exc)
return None, None
return curr_cache, previous_cache
def find_priority_instance(self, instance):
current_cache, previous_cache = \
self.get_current_and_previous_cache(instance)
if None in (current_cache, previous_cache):
LOG.warning("Datasource unable to pick L3 Cache "
"values. Skipping the instance")
return None
if (current_cache < (1 - (self.cache_threshold / 100.0)) *
previous_cache):
return instance
else:
return None
def find_noisy_instance(self, instance):
noisy_current_cache, noisy_previous_cache = \
self.get_current_and_previous_cache(instance)
if None in (noisy_current_cache, noisy_previous_cache):
LOG.warning("Datasource unable to pick "
"L3 Cache. Skipping the instance")
return None
if (noisy_current_cache > (1 + (self.cache_threshold / 100.0)) *
noisy_previous_cache):
return instance
else:
return None
def group_hosts(self):
nodes = self.compute_model.get_all_compute_nodes()
hosts_need_release = {}
hosts_target = []
for node in nodes.values():
instances_of_node = self.compute_model.get_node_instances(node)
node_instance_count = len(instances_of_node)
# Flag that tells us whether to skip the node or not. If True,
# the node is skipped. Will be true if we find a noisy instance or
# when potential priority instance will be same as potential noisy
# instance
loop_break_flag = False
if node_instance_count > 1:
instance_priority_list = []
for instance in instances_of_node:
instance_priority_list.append(instance)
# If there is no metadata regarding watcher-priority, it takes
# DEFAULT_WATCHER_PRIORITY as priority.
instance_priority_list.sort(key=lambda a: (
a.get('metadata').get('watcher-priority'),
self.DEFAULT_WATCHER_PRIORITY))
instance_priority_list_reverse = list(instance_priority_list)
instance_priority_list_reverse.reverse()
for potential_priority_instance in instance_priority_list:
priority_instance = self.find_priority_instance(
potential_priority_instance)
if (priority_instance is not None):
for potential_noisy_instance in (
instance_priority_list_reverse):
if (potential_noisy_instance ==
potential_priority_instance):
loop_break_flag = True
break
noisy_instance = self.find_noisy_instance(
potential_noisy_instance)
if noisy_instance is not None:
hosts_need_release[node.uuid] = {
'priority_vm': potential_priority_instance,
'noisy_vm': potential_noisy_instance}
LOG.debug("Priority VM found: %s",
potential_priority_instance.uuid)
LOG.debug("Noisy VM found: %s",
potential_noisy_instance.uuid)
loop_break_flag = True
break
# No need to check other instances in the node
if loop_break_flag is True:
break
if node.uuid not in hosts_need_release:
hosts_target.append(node)
return hosts_need_release, hosts_target
def filter_dest_servers(self, hosts, instance_to_migrate):
required_cores = instance_to_migrate.vcpus
required_disk = instance_to_migrate.disk
required_memory = instance_to_migrate.memory
dest_servers = []
for host in hosts:
free_res = self.compute_model.get_node_free_resources(host)
if (free_res['vcpu'] >= required_cores and free_res['disk'] >=
required_disk and free_res['memory'] >= required_memory):
dest_servers.append(host)
return dest_servers
def pre_execute(self):
self._pre_execute()
def do_execute(self, audit=None):
self.cache_threshold = self.input_parameters.cache_threshold
self.period = self.input_parameters.period
hosts_need_release, hosts_target = self.group_hosts()
if len(hosts_need_release) == 0:
LOG.debug("No hosts require optimization")
return
if len(hosts_target) == 0:
LOG.debug("No hosts available to migrate")
return
mig_source_node_name = max(hosts_need_release.keys(), key=lambda a:
hosts_need_release[a]['priority_vm'])
instance_to_migrate = hosts_need_release[mig_source_node_name][
'noisy_vm']
if instance_to_migrate is None:
return
dest_servers = self.filter_dest_servers(hosts_target,
instance_to_migrate)
if len(dest_servers) == 0:
LOG.info("No proper target host could be found")
return
# Destination node will be the first available node in the list.
mig_destination_node = dest_servers[0]
mig_source_node = self.compute_model.get_node_by_uuid(
mig_source_node_name)
if self.compute_model.migrate_instance(instance_to_migrate,
mig_source_node,
mig_destination_node):
parameters = {'migration_type': 'live',
'source_node': mig_source_node.uuid,
'destination_node': mig_destination_node.uuid,
'resource_name': instance_to_migrate.name}
self.solution.add_action(action_type=self.MIGRATION,
resource_id=instance_to_migrate.uuid,
input_parameters=parameters)
def post_execute(self):
self.solution.model = self.compute_model
LOG.debug(self.compute_model.to_string())
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