nova/nova/scheduler/filters/io_ops_filter.py

44 lines
1.6 KiB
Python

# Copyright (c) 2012 OpenStack, LLC.
# 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 nova.openstack.common import cfg
from nova.openstack.common import log as logging
from nova.scheduler import filters
LOG = logging.getLogger(__name__)
max_io_ops_per_host_opt = cfg.IntOpt("max_io_ops_per_host",
default=8,
help="Ignore hosts that have too many builds/resizes/snaps/migrations")
CONF = cfg.CONF
CONF.register_opt(max_io_ops_per_host_opt)
class IoOpsFilter(filters.BaseHostFilter):
"""Filter out hosts with too many concurrent I/O operations."""
def host_passes(self, host_state, filter_properties):
"""Use information about current vm and task states collected from
compute node statistics to decide whether to filter.
"""
num_io_ops = host_state.num_io_ops
max_io_ops = CONF.max_io_ops_per_host
passes = num_io_ops < max_io_ops
if not passes:
LOG.debug(_("%(host_state)s fails I/O ops check: Max IOs per host "
"is set to %(max_io_ops)s"), locals())
return passes