Files
python-ganttclient/nova/scheduler/multi.py
Sandy Walsh bf1155dfb5 Removed zones from api and distributed scheduler
There is a new Zones implementation coming that will use AMQP-to-AMQP
channels vs. the public API. This is being done for three reasons:
1. remove complications in the OpenStack API (and possibly allow EC2 Zones)
2. remove dependencies on keystone and novaclient
3. faster scheduling (fewer chances for race conditions)

Learn more here:
http://wiki.openstack.org/EssexSchedulerImprovements

Change-Id: I6fe538923dd5ae19276afac2ac3311a285fd5c99
2012-02-16 17:53:00 +00:00

77 lines
2.7 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# 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.
"""
Scheduler that allows routing some calls to one driver and others to another.
"""
from nova import flags
from nova.openstack.common import cfg
from nova import utils
from nova.scheduler import driver
multi_scheduler_opts = [
cfg.StrOpt('compute_scheduler_driver',
default='nova.scheduler.chance.ChanceScheduler',
help='Driver to use for scheduling compute calls'),
cfg.StrOpt('volume_scheduler_driver',
default='nova.scheduler.chance.ChanceScheduler',
help='Driver to use for scheduling volume calls'),
]
FLAGS = flags.FLAGS
FLAGS.register_opts(multi_scheduler_opts)
# A mapping of methods to topics so we can figure out which driver to use.
_METHOD_MAP = {'run_instance': 'compute',
'prep_resize': 'compute',
'live_migration': 'compute',
'create_volume': 'volume',
'create_volumes': 'volume'}
class MultiScheduler(driver.Scheduler):
"""A scheduler that holds multiple sub-schedulers.
This exists to allow flag-driven composibility of schedulers, allowing
third parties to integrate custom schedulers more easily.
"""
def __init__(self):
super(MultiScheduler, self).__init__()
compute_driver = utils.import_object(FLAGS.compute_scheduler_driver)
volume_driver = utils.import_object(FLAGS.volume_scheduler_driver)
self.drivers = {'compute': compute_driver,
'volume': volume_driver}
def __getattr__(self, key):
if not key.startswith('schedule_'):
raise AttributeError(key)
method = key[len('schedule_'):]
if method not in _METHOD_MAP:
raise AttributeError(key)
return getattr(self.drivers[_METHOD_MAP[method]], key)
def schedule(self, context, topic, method, *_args, **_kwargs):
return self.drivers[topic].schedule(context, topic,
method, *_args, **_kwargs)