nova-solver-scheduler/nova/scheduler/solvers/constraints/aggregate_vcpu.py

60 lines
2.3 KiB
Python

# Copyright (c) 2014 Cisco Systems Inc.
# All Rights Reserved.
#
# 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 oslo.config import cfg
from nova import db
from nova.openstack.common.gettextutils import _
from nova.openstack.common import log as logging
from nova.scheduler.solvers.constraints import vcpu_constraint
CONF = cfg.CONF
CONF.import_opt('cpu_allocation_ratio', 'nova.scheduler.filters.core_filter')
LOG = logging.getLogger(__name__)
class AggregateVcpuConstraint(vcpu_constraint.VcpuConstraint):
"""AggregateVcpuConstraint with per-aggregate CPU subscription flag.
Fall back to global cpu_allocation_ratio if no per-aggregate setting found.
"""
def _get_cpu_allocation_ratio(self, host_state, filter_properties):
context = filter_properties['context'].elevated()
# TODO(uni): DB query in filter is a performance hit, especially for
# system with lots of hosts. Will need a general solution here to fix
# all filters with aggregate DB call things.
metadata = db.aggregate_metadata_get_by_host(
context, host_state.host, key='cpu_allocation_ratio')
aggregate_vals = metadata.get('cpu_allocation_ratio', set())
num_values = len(aggregate_vals)
if num_values == 0:
return CONF.cpu_allocation_ratio
if num_values > 1:
LOG.warning(_("%(num_values)d ratio values found, "
"of which the minimum value will be used."),
{'num_values': num_values})
try:
ratio = min(map(float, aggregate_vals))
except ValueError as e:
LOG.warning(_("Could not decode cpu_allocation_ratio: '%s'"), e)
ratio = CONF.cpu_allocation_ratio
return ratio