deb-manila/manila/scheduler/chance.py
Thomas Bechtold 071d0b59c1 Switch to using oslo_* instead of oslo.*
The oslo team is recommending everyone to switch to the
non-namespaced versions of libraries. Updating the hacking
rule to include a check to prevent oslo.* import from
creeping back in.
oslo.messaging is the only exception because this package doesn't
currently support non-namespaced imports.

Change-Id: I3987e651bc880c8ffa7c0105df0298679dcd3a43
2015-01-27 09:19:50 +01:00

73 lines
2.6 KiB
Python

# Copyright (c) 2010 OpenStack, LLC.
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.
"""
Chance (Random) Scheduler implementation
"""
import random
from oslo_config import cfg
from manila import exception
from manila.i18n import _
from manila.scheduler import driver
CONF = cfg.CONF
class ChanceScheduler(driver.Scheduler):
"""Implements Scheduler as a random node selector."""
def _filter_hosts(self, request_spec, hosts, **kwargs):
"""Filter a list of hosts based on request_spec."""
filter_properties = kwargs.get('filter_properties', {})
ignore_hosts = filter_properties.get('ignore_hosts', [])
hosts = [host for host in hosts if host not in ignore_hosts]
return hosts
def _schedule(self, context, topic, request_spec, **kwargs):
"""Picks a host that is up at random."""
elevated = context.elevated()
hosts = self.hosts_up(elevated, topic)
if not hosts:
msg = _("Is the appropriate service running?")
raise exception.NoValidHost(reason=msg)
hosts = self._filter_hosts(request_spec, hosts, **kwargs)
if not hosts:
msg = _("Could not find another host")
raise exception.NoValidHost(reason=msg)
return hosts[int(random.random() * len(hosts))]
def schedule_create_share(self, context, request_spec, filter_properties):
"""Picks a host that is up at random."""
topic = CONF.share_topic
host = self._schedule(context, topic, request_spec,
filter_properties=filter_properties)
share_id = request_spec['share_id']
snapshot_id = request_spec['snapshot_id']
updated_share = driver.share_update_db(context, share_id, host)
self.share_rpcapi.create_share(context, updated_share, host,
request_spec,
filter_properties,
snapshot_id)