magnum/magnum/conductor/scale_manager.py

90 lines
3.3 KiB
Python
Executable File

# Copyright 2015 Huawei Technologies Co.,LTD.
#
# 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.
import abc
from oslo_log import log as logging
from magnum.common import exception
from magnum.drivers.common.driver import Driver
from magnum.i18n import _
from magnum import objects
LOG = logging.getLogger(__name__)
def get_scale_manager(context, osclient, cluster):
cluster_driver = Driver.get_driver_for_cluster(context, cluster)
manager = cluster_driver.get_scale_manager(context, osclient, cluster)
if not manager:
LOG.warning(
"Currently only kubernetes and mesos cluster scale manager "
"are available")
return manager
class ScaleManager(object):
def __init__(self, context, osclient, cluster):
self.context = context
self.osclient = osclient
self.old_cluster = objects.Cluster.get_by_uuid(context, cluster.uuid)
self.new_cluster = cluster
def get_removal_nodes(self, hosts_output):
if not self._is_scale_down():
return list()
cluster = self.new_cluster
stack = self.osclient.heat().stacks.get(cluster.stack_id)
hosts = hosts_output.get_output_value(stack)
if hosts is None:
raise exception.MagnumException(_(
"Output key '%(output_key)s' is missing from stack "
"%(stack_id)s") % {'output_key': hosts_output.heat_output,
'stack_id': stack.id})
hosts_with_container = self._get_hosts_with_container(self.context,
cluster)
hosts_no_container = list(set(hosts) - hosts_with_container)
LOG.debug('List of hosts that has no container: %s',
str(hosts_no_container))
num_of_removal = self._get_num_of_removal()
if len(hosts_no_container) < num_of_removal:
LOG.warning(
"About to remove %(num_removal)d nodes, which is larger than "
"the number of empty nodes (%(num_empty)d). %(num_non_empty)d "
"non-empty nodes will be removed.", {
'num_removal': num_of_removal,
'num_empty': len(hosts_no_container),
'num_non_empty': num_of_removal - len(hosts_no_container)})
hosts_to_remove = hosts_no_container[0:num_of_removal]
LOG.info('Require removal of hosts: %s', hosts_to_remove)
return hosts_to_remove
def _is_scale_down(self):
return self.new_cluster.node_count < self.old_cluster.node_count
def _get_num_of_removal(self):
return self.old_cluster.node_count - self.new_cluster.node_count
@abc.abstractmethod
def _get_hosts_with_container(self, context, cluster):
"""Return the hosts with container running on them."""
pass