300 lines
11 KiB
Python
300 lines
11 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 base class that all Schedulers should inherit from
|
|
"""
|
|
|
|
import datetime
|
|
|
|
from nova import db
|
|
from nova import exception
|
|
from nova import flags
|
|
from nova import log as logging
|
|
from nova import rpc
|
|
from nova import utils
|
|
from nova.compute import power_state
|
|
|
|
FLAGS = flags.FLAGS
|
|
flags.DEFINE_integer('service_down_time', 60,
|
|
'maximum time since last checkin for up service')
|
|
flags.DECLARE('instances_path', 'nova.compute.manager')
|
|
|
|
|
|
class NoValidHost(exception.Error):
|
|
"""There is no valid host for the command."""
|
|
pass
|
|
|
|
|
|
class WillNotSchedule(exception.Error):
|
|
"""The specified host is not up or doesn't exist."""
|
|
pass
|
|
|
|
|
|
class Scheduler(object):
|
|
"""The base class that all Scheduler clases should inherit from."""
|
|
|
|
def __init__(self):
|
|
self.zone_manager = None
|
|
|
|
def set_zone_manager(self, zone_manager):
|
|
"""Called by the Scheduler Service to supply a ZoneManager."""
|
|
self.zone_manager = zone_manager
|
|
|
|
@staticmethod
|
|
def service_is_up(service):
|
|
"""Check whether a service is up based on last heartbeat."""
|
|
last_heartbeat = service['updated_at'] or service['created_at']
|
|
# Timestamps in DB are UTC.
|
|
elapsed = utils.utcnow() - last_heartbeat
|
|
return elapsed < datetime.timedelta(seconds=FLAGS.service_down_time)
|
|
|
|
def hosts_up(self, context, topic):
|
|
"""Return the list of hosts that have a running service for topic."""
|
|
|
|
services = db.service_get_all_by_topic(context, topic)
|
|
return [service.host
|
|
for service in services
|
|
if self.service_is_up(service)]
|
|
|
|
def schedule(self, context, topic, *_args, **_kwargs):
|
|
"""Must override at least this method for scheduler to work."""
|
|
raise NotImplementedError(_("Must implement a fallback schedule"))
|
|
|
|
def schedule_live_migration(self, context, instance_id, dest):
|
|
"""Live migration scheduling method.
|
|
|
|
:param context:
|
|
:param instance_id:
|
|
:param dest: destination host
|
|
:return:
|
|
The host where instance is running currently.
|
|
Then scheduler send request that host.
|
|
|
|
"""
|
|
|
|
# Whether instance exists and is running.
|
|
instance_ref = db.instance_get(context, instance_id)
|
|
|
|
# Checking instance.
|
|
self._live_migration_src_check(context, instance_ref)
|
|
|
|
# Checking destination host.
|
|
self._live_migration_dest_check(context, instance_ref, dest)
|
|
|
|
# Common checking.
|
|
self._live_migration_common_check(context, instance_ref, dest)
|
|
|
|
# Changing instance_state.
|
|
db.instance_set_state(context,
|
|
instance_id,
|
|
power_state.PAUSED,
|
|
'migrating')
|
|
|
|
# Changing volume state
|
|
for volume_ref in instance_ref['volumes']:
|
|
db.volume_update(context,
|
|
volume_ref['id'],
|
|
{'status': 'migrating'})
|
|
|
|
# Return value is necessary to send request to src
|
|
# Check _schedule() in detail.
|
|
src = instance_ref['host']
|
|
return src
|
|
|
|
def _live_migration_src_check(self, context, instance_ref):
|
|
"""Live migration check routine (for src host).
|
|
|
|
:param context: security context
|
|
:param instance_ref: nova.db.sqlalchemy.models.Instance object
|
|
|
|
"""
|
|
|
|
# Checking instance is running.
|
|
if (power_state.RUNNING != instance_ref['state'] or \
|
|
'running' != instance_ref['state_description']):
|
|
ec2_id = instance_ref['hostname']
|
|
raise exception.InstanceNotRunning(instance_id=ec2_id)
|
|
|
|
# Checing volume node is running when any volumes are mounted
|
|
# to the instance.
|
|
if len(instance_ref['volumes']) != 0:
|
|
services = db.service_get_all_by_topic(context, 'volume')
|
|
if len(services) < 1 or not self.service_is_up(services[0]):
|
|
raise exception.VolumeServiceUnavailable()
|
|
|
|
# Checking src host exists and compute node
|
|
src = instance_ref['host']
|
|
services = db.service_get_all_compute_by_host(context, src)
|
|
|
|
# Checking src host is alive.
|
|
if not self.service_is_up(services[0]):
|
|
raise exception.ComputeServiceUnavailable(host=src)
|
|
|
|
def _live_migration_dest_check(self, context, instance_ref, dest):
|
|
"""Live migration check routine (for destination host).
|
|
|
|
:param context: security context
|
|
:param instance_ref: nova.db.sqlalchemy.models.Instance object
|
|
:param dest: destination host
|
|
|
|
"""
|
|
|
|
# Checking dest exists and compute node.
|
|
dservice_refs = db.service_get_all_compute_by_host(context, dest)
|
|
dservice_ref = dservice_refs[0]
|
|
|
|
# Checking dest host is alive.
|
|
if not self.service_is_up(dservice_ref):
|
|
raise exception.ComputeServiceUnavailable(host=dest)
|
|
|
|
# Checking whether The host where instance is running
|
|
# and dest is not same.
|
|
src = instance_ref['host']
|
|
if dest == src:
|
|
ec2_id = instance_ref['hostname']
|
|
raise exception.UnableToMigrateToSelf(instance_id=ec2_id,
|
|
host=dest)
|
|
|
|
# Checking dst host still has enough capacities.
|
|
self.assert_compute_node_has_enough_resources(context,
|
|
instance_ref,
|
|
dest)
|
|
|
|
def _live_migration_common_check(self, context, instance_ref, dest):
|
|
"""Live migration common check routine.
|
|
|
|
Below checkings are followed by
|
|
http://wiki.libvirt.org/page/TodoPreMigrationChecks
|
|
|
|
:param context: security context
|
|
:param instance_ref: nova.db.sqlalchemy.models.Instance object
|
|
:param dest: destination host
|
|
|
|
"""
|
|
|
|
# Checking shared storage connectivity
|
|
self.mounted_on_same_shared_storage(context, instance_ref, dest)
|
|
|
|
# Checking dest exists.
|
|
dservice_refs = db.service_get_all_compute_by_host(context, dest)
|
|
dservice_ref = dservice_refs[0]['compute_node'][0]
|
|
|
|
# Checking original host( where instance was launched at) exists.
|
|
try:
|
|
oservice_refs = db.service_get_all_compute_by_host(context,
|
|
instance_ref['launched_on'])
|
|
except exception.NotFound:
|
|
raise exception.SourceHostUnavailable()
|
|
oservice_ref = oservice_refs[0]['compute_node'][0]
|
|
|
|
# Checking hypervisor is same.
|
|
orig_hypervisor = oservice_ref['hypervisor_type']
|
|
dest_hypervisor = dservice_ref['hypervisor_type']
|
|
if orig_hypervisor != dest_hypervisor:
|
|
raise exception.InvalidHypervisorType()
|
|
|
|
# Checkng hypervisor version.
|
|
orig_hypervisor = oservice_ref['hypervisor_version']
|
|
dest_hypervisor = dservice_ref['hypervisor_version']
|
|
if orig_hypervisor > dest_hypervisor:
|
|
raise exception.DestinationHypervisorTooOld()
|
|
|
|
# Checking cpuinfo.
|
|
try:
|
|
rpc.call(context,
|
|
db.queue_get_for(context, FLAGS.compute_topic, dest),
|
|
{"method": 'compare_cpu',
|
|
"args": {'cpu_info': oservice_ref['cpu_info']}})
|
|
|
|
except rpc.RemoteError:
|
|
src = instance_ref['host']
|
|
logging.exception(_("host %(dest)s is not compatible with "
|
|
"original host %(src)s.") % locals())
|
|
raise
|
|
|
|
def assert_compute_node_has_enough_resources(self, context,
|
|
instance_ref, dest):
|
|
"""Checks if destination host has enough resource for live migration.
|
|
|
|
Currently, only memory checking has been done.
|
|
If storage migration(block migration, meaning live-migration
|
|
without any shared storage) will be available, local storage
|
|
checking is also necessary.
|
|
|
|
:param context: security context
|
|
:param instance_ref: nova.db.sqlalchemy.models.Instance object
|
|
:param dest: destination host
|
|
|
|
"""
|
|
|
|
# Getting instance information
|
|
ec2_id = instance_ref['hostname']
|
|
|
|
# Getting host information
|
|
service_refs = db.service_get_all_compute_by_host(context, dest)
|
|
compute_node_ref = service_refs[0]['compute_node'][0]
|
|
|
|
mem_total = int(compute_node_ref['memory_mb'])
|
|
mem_used = int(compute_node_ref['memory_mb_used'])
|
|
mem_avail = mem_total - mem_used
|
|
mem_inst = instance_ref['memory_mb']
|
|
if mem_avail <= mem_inst:
|
|
reason = _("Unable to migrate %(ec2_id)s to destination: %(dest)s "
|
|
"(host:%(mem_avail)s <= instance:%(mem_inst)s)")
|
|
raise exception.MigrationError(reason=reason % locals())
|
|
|
|
def mounted_on_same_shared_storage(self, context, instance_ref, dest):
|
|
"""Check if the src and dest host mount same shared storage.
|
|
|
|
At first, dest host creates temp file, and src host can see
|
|
it if they mounts same shared storage. Then src host erase it.
|
|
|
|
:param context: security context
|
|
:param instance_ref: nova.db.sqlalchemy.models.Instance object
|
|
:param dest: destination host
|
|
|
|
"""
|
|
|
|
src = instance_ref['host']
|
|
dst_t = db.queue_get_for(context, FLAGS.compute_topic, dest)
|
|
src_t = db.queue_get_for(context, FLAGS.compute_topic, src)
|
|
|
|
try:
|
|
# create tmpfile at dest host
|
|
filename = rpc.call(context, dst_t,
|
|
{"method": 'create_shared_storage_test_file'})
|
|
|
|
# make sure existence at src host.
|
|
rpc.call(context, src_t,
|
|
{"method": 'check_shared_storage_test_file',
|
|
"args": {'filename': filename}})
|
|
|
|
except rpc.RemoteError:
|
|
ipath = FLAGS.instances_path
|
|
logging.error(_("Cannot confirm tmpfile at %(ipath)s is on "
|
|
"same shared storage between %(src)s "
|
|
"and %(dest)s.") % locals())
|
|
raise
|
|
|
|
finally:
|
|
rpc.call(context, dst_t,
|
|
{"method": 'cleanup_shared_storage_test_file',
|
|
"args": {'filename': filename}})
|