gantt/nova/scheduler/multi.py
Mark McLoughlin 9e1d5467f6 Switch from FLAGS to CONF in nova.scheduler
Use the global CONF variable instead of FLAGS. This is purely a cleanup
since FLAGS is already just another reference to CONF.

We leave the nova.flags imports until a later cleanup commit since
removing them may cause unpredictable problems due to config options not
being registered.

Change-Id: Ia3f66aec300fd88e91cef926da735f9e95aa2cc2
2012-11-04 22:33:01 +00:00

80 lines
2.9 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.
This scheduler was originally used to deal with both compute and volume. But
is now used for openstack extensions that want to use the nova-scheduler to
schedule requests to compute nodes but provide their own manager and topic.
https://bugs.launchpad.net/nova/+bug/1009681
"""
from nova import config
from nova import flags
from nova.openstack.common import cfg
from nova.openstack.common import importutils
from nova.scheduler import driver
multi_scheduler_opts = [
cfg.StrOpt('compute_scheduler_driver',
default='nova.scheduler.'
'filter_scheduler.FilterScheduler',
help='Driver to use for scheduling compute calls'),
cfg.StrOpt('default_scheduler_driver',
default='nova.scheduler.chance.ChanceScheduler',
help='Default driver to use for scheduling calls'),
]
CONF = config.CONF
CONF.register_opts(multi_scheduler_opts)
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 = importutils.import_object(
CONF.compute_scheduler_driver)
default_driver = importutils.import_object(
CONF.default_scheduler_driver)
self.drivers = {'compute': compute_driver,
'default': default_driver}
def schedule_run_instance(self, *args, **kwargs):
return self.drivers['compute'].schedule_run_instance(*args, **kwargs)
def schedule_prep_resize(self, *args, **kwargs):
return self.drivers['compute'].schedule_prep_resize(*args, **kwargs)
def update_service_capabilities(self, service_name, host, capabilities):
# Multi scheduler is only a holder of sub-schedulers, so
# pass the capabilities to the schedulers that matter
for d in self.drivers.values():
d.update_service_capabilities(service_name, host, capabilities)