Files
python-ganttclient/nova/scheduler/simple.py
2011-03-31 14:29:16 -05:00

129 lines
6.0 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.
"""
Simple Scheduler
"""
import datetime
from nova import db
from nova import flags
from nova.scheduler import driver
from nova.scheduler import chance
FLAGS = flags.FLAGS
flags.DEFINE_integer("max_cores", 16,
"maximum number of instance cores to allow per host")
flags.DEFINE_integer("max_gigabytes", 10000,
"maximum number of volume gigabytes to allow per host")
flags.DEFINE_integer("max_networks", 1000,
"maximum number of networks to allow per host")
class SimpleScheduler(chance.ChanceScheduler):
"""Implements Naive Scheduler that tries to find least loaded host."""
def schedule_run_instance(self, context, instance_id, *_args, **_kwargs):
"""Picks a host that is up and has the fewest running instances."""
instance_ref = db.instance_get(context, instance_id)
if (instance_ref['availability_zone']
and ':' in instance_ref['availability_zone']
and context.is_admin):
zone, _x, host = instance_ref['availability_zone'].partition(':')
service = db.service_get_by_args(context.elevated(), host,
'nova-compute')
if not self.service_is_up(service):
raise driver.WillNotSchedule(_("Host %s is not alive") % host)
# TODO(vish): this probably belongs in the manager, if we
# can generalize this somehow
now = datetime.datetime.utcnow()
db.instance_update(context, instance_id, {'host': host,
'scheduled_at': now})
return host
results = db.service_get_all_compute_sorted(context)
for result in results:
(service, instance_cores) = result
if instance_cores + instance_ref['vcpus'] > FLAGS.max_cores:
raise driver.NoValidHost(_("All hosts have too many cores"))
if self.service_is_up(service):
# NOTE(vish): this probably belongs in the manager, if we
# can generalize this somehow
now = datetime.datetime.utcnow()
db.instance_update(context,
instance_id,
{'host': service['host'],
'scheduled_at': now})
return service['host']
raise driver.NoValidHost(_("Scheduler was unable to locate a host"
" for this request. Is the appropriate"
" service running?"))
def schedule_create_volume(self, context, volume_id, *_args, **_kwargs):
"""Picks a host that is up and has the fewest volumes."""
volume_ref = db.volume_get(context, volume_id)
if (volume_ref['availability_zone']
and ':' in volume_ref['availability_zone']
and context.is_admin):
zone, _x, host = volume_ref['availability_zone'].partition(':')
service = db.service_get_by_args(context.elevated(), host,
'nova-volume')
if not self.service_is_up(service):
raise driver.WillNotSchedule(_("Host %s not available") % host)
# TODO(vish): this probably belongs in the manager, if we
# can generalize this somehow
now = datetime.datetime.utcnow()
db.volume_update(context, volume_id, {'host': host,
'scheduled_at': now})
return host
results = db.service_get_all_volume_sorted(context)
for result in results:
(service, volume_gigabytes) = result
if volume_gigabytes + volume_ref['size'] > FLAGS.max_gigabytes:
raise driver.NoValidHost(_("All hosts have too many "
"gigabytes"))
if self.service_is_up(service):
# NOTE(vish): this probably belongs in the manager, if we
# can generalize this somehow
now = datetime.datetime.utcnow()
db.volume_update(context,
volume_id,
{'host': service['host'],
'scheduled_at': now})
return service['host']
raise driver.NoValidHost(_("Scheduler was unable to locate a host"
" for this request. Is the appropriate"
" service running?"))
def schedule_set_network_host(self, context, *_args, **_kwargs):
"""Picks a host that is up and has the fewest networks."""
results = db.service_get_all_network_sorted(context)
for result in results:
(service, instance_count) = result
if instance_count >= FLAGS.max_networks:
raise driver.NoValidHost(_("All hosts have too many networks"))
if self.service_is_up(service):
return service['host']
raise driver.NoValidHost(_("Scheduler was unable to locate a host"
" for this request. Is the appropriate"
" service running?"))