nova/nova/scheduler/host_manager.py

432 lines
17 KiB
Python

# Copyright (c) 2011 OpenStack Foundation
# 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.
"""
Manage hosts in the current zone.
"""
import UserDict
from oslo.config import cfg
from nova.compute import task_states
from nova.compute import vm_states
from nova import db
from nova import exception
from nova.openstack.common import log as logging
from nova.openstack.common import timeutils
from nova.scheduler import filters
from nova.scheduler import weights
host_manager_opts = [
cfg.MultiStrOpt('scheduler_available_filters',
default=['nova.scheduler.filters.all_filters'],
help='Filter classes available to the scheduler which may '
'be specified more than once. An entry of '
'"nova.scheduler.filters.standard_filters" '
'maps to all filters included with nova.'),
cfg.ListOpt('scheduler_default_filters',
default=[
'RetryFilter',
'AvailabilityZoneFilter',
'RamFilter',
'ComputeFilter',
'ComputeCapabilitiesFilter',
'ImagePropertiesFilter'
],
help='Which filter class names to use for filtering hosts '
'when not specified in the request.'),
cfg.ListOpt('scheduler_weight_classes',
default=['nova.scheduler.weights.all_weighers'],
help='Which weight class names to use for weighing hosts'),
]
CONF = cfg.CONF
CONF.register_opts(host_manager_opts)
LOG = logging.getLogger(__name__)
class ReadOnlyDict(UserDict.IterableUserDict):
"""A read-only dict."""
def __init__(self, source=None):
self.data = {}
self.update(source)
def __setitem__(self, key, item):
raise TypeError()
def __delitem__(self, key):
raise TypeError()
def clear(self):
raise TypeError()
def pop(self, key, *args):
raise TypeError()
def popitem(self):
raise TypeError()
def update(self, source=None):
if source is None:
return
elif isinstance(source, UserDict.UserDict):
self.data = source.data
elif isinstance(source, type({})):
self.data = source
else:
raise TypeError()
class HostState(object):
"""Mutable and immutable information tracked for a host.
This is an attempt to remove the ad-hoc data structures
previously used and lock down access.
"""
def __init__(self, host, node, capabilities=None, service=None):
self.host = host
self.nodename = node
self.update_capabilities(capabilities, service)
# Mutable available resources.
# These will change as resources are virtually "consumed".
self.total_usable_disk_gb = 0
self.disk_mb_used = 0
self.free_ram_mb = 0
self.free_disk_mb = 0
self.vcpus_total = 0
self.vcpus_used = 0
# Valid vm types on this host: 'pv', 'hvm' or 'all'
if 'allowed_vm_type' in self.capabilities:
self.allowed_vm_type = self.capabilities['allowed_vm_type']
else:
self.allowed_vm_type = 'all'
# Additional host information from the compute node stats:
self.vm_states = {}
self.task_states = {}
self.num_instances = 0
self.num_instances_by_project = {}
self.num_instances_by_os_type = {}
self.num_io_ops = 0
# Resource oversubscription values for the compute host:
self.limits = {}
self.updated = None
def update_capabilities(self, capabilities=None, service=None):
# Read-only capability dicts
if capabilities is None:
capabilities = {}
self.capabilities = ReadOnlyDict(capabilities)
if service is None:
service = {}
self.service = ReadOnlyDict(service)
def update_from_compute_node(self, compute):
"""Update information about a host from its compute_node info."""
if (self.updated and compute['updated_at']
and self.updated > compute['updated_at']):
return
all_ram_mb = compute['memory_mb']
# Assume virtual size is all consumed by instances if use qcow2 disk.
least = compute.get('disk_available_least')
free_disk_mb = least if least is not None else compute['free_disk_gb']
free_disk_mb *= 1024
self.disk_mb_used = compute['local_gb_used'] * 1024
#NOTE(jogo) free_ram_mb can be negative
self.free_ram_mb = compute['free_ram_mb']
self.total_usable_ram_mb = all_ram_mb
self.total_usable_disk_gb = compute['local_gb']
self.free_disk_mb = free_disk_mb
self.vcpus_total = compute['vcpus']
self.vcpus_used = compute['vcpus_used']
self.updated = compute['updated_at']
stats = compute.get('stats', [])
statmap = self._statmap(stats)
# Track number of instances on host
self.num_instances = int(statmap.get('num_instances', 0))
# Track number of instances by project_id
project_id_keys = [k for k in statmap.keys() if
k.startswith("num_proj_")]
for key in project_id_keys:
project_id = key[9:]
self.num_instances_by_project[project_id] = int(statmap[key])
# Track number of instances in certain vm_states
vm_state_keys = [k for k in statmap.keys() if k.startswith("num_vm_")]
for key in vm_state_keys:
vm_state = key[7:]
self.vm_states[vm_state] = int(statmap[key])
# Track number of instances in certain task_states
task_state_keys = [k for k in statmap.keys() if
k.startswith("num_task_")]
for key in task_state_keys:
task_state = key[9:]
self.task_states[task_state] = int(statmap[key])
# Track number of instances by host_type
os_keys = [k for k in statmap.keys() if k.startswith("num_os_type_")]
for key in os_keys:
os = key[12:]
self.num_instances_by_os_type[os] = int(statmap[key])
self.num_io_ops = int(statmap.get('io_workload', 0))
def consume_from_instance(self, instance):
"""Incrementally update host state from an instance."""
disk_mb = (instance['root_gb'] + instance['ephemeral_gb']) * 1024
ram_mb = instance['memory_mb']
vcpus = instance['vcpus']
self.free_ram_mb -= ram_mb
self.free_disk_mb -= disk_mb
self.vcpus_used += vcpus
self.updated = timeutils.utcnow()
# Track number of instances on host
self.num_instances += 1
# Track number of instances by project_id
project_id = instance.get('project_id')
if project_id not in self.num_instances_by_project:
self.num_instances_by_project[project_id] = 0
self.num_instances_by_project[project_id] += 1
# Track number of instances in certain vm_states
vm_state = instance.get('vm_state', vm_states.BUILDING)
if vm_state not in self.vm_states:
self.vm_states[vm_state] = 0
self.vm_states[vm_state] += 1
# Track number of instances in certain task_states
task_state = instance.get('task_state')
if task_state not in self.task_states:
self.task_states[task_state] = 0
self.task_states[task_state] += 1
# Track number of instances by host_type
os_type = instance.get('os_type')
if os_type not in self.num_instances_by_os_type:
self.num_instances_by_os_type[os_type] = 0
self.num_instances_by_os_type[os_type] += 1
vm_state = instance.get('vm_state', vm_states.BUILDING)
task_state = instance.get('task_state')
if vm_state == vm_states.BUILDING or task_state in [
task_states.RESIZE_MIGRATING, task_states.REBUILDING,
task_states.RESIZE_PREP, task_states.IMAGE_SNAPSHOT,
task_states.IMAGE_BACKUP]:
self.num_io_ops += 1
def _statmap(self, stats):
return dict((st['key'], st['value']) for st in stats)
def __repr__(self):
return ("(%s, %s) ram:%s disk:%s io_ops:%s instances:%s vm_type:%s" %
(self.host, self.nodename, self.free_ram_mb, self.free_disk_mb,
self.num_io_ops, self.num_instances, self.allowed_vm_type))
class HostManager(object):
"""Base HostManager class."""
# Can be overridden in a subclass
host_state_cls = HostState
def __init__(self):
# { (host, hypervisor_hostname) : { <service> : { cap k : v }}}
self.service_states = {}
self.host_state_map = {}
self.filter_handler = filters.HostFilterHandler()
self.filter_classes = self.filter_handler.get_matching_classes(
CONF.scheduler_available_filters)
self.weight_handler = weights.HostWeightHandler()
self.weight_classes = self.weight_handler.get_matching_classes(
CONF.scheduler_weight_classes)
def _choose_host_filters(self, filter_cls_names):
"""Since the caller may specify which filters to use we need
to have an authoritative list of what is permissible. This
function checks the filter names against a predefined set
of acceptable filters.
"""
if filter_cls_names is None:
filter_cls_names = CONF.scheduler_default_filters
if not isinstance(filter_cls_names, (list, tuple)):
filter_cls_names = [filter_cls_names]
good_filters = []
bad_filters = []
for filter_name in filter_cls_names:
found_class = False
for cls in self.filter_classes:
if cls.__name__ == filter_name:
good_filters.append(cls)
found_class = True
break
if not found_class:
bad_filters.append(filter_name)
if bad_filters:
msg = ", ".join(bad_filters)
raise exception.SchedulerHostFilterNotFound(filter_name=msg)
return good_filters
def get_filtered_hosts(self, hosts, filter_properties,
filter_class_names=None):
"""Filter hosts and return only ones passing all filters."""
def _strip_ignore_hosts(host_map, hosts_to_ignore):
ignored_hosts = []
for host in hosts_to_ignore:
for (hostname, nodename) in host_map.keys():
if host == hostname:
del host_map[(hostname, nodename)]
ignored_hosts.append(host)
ignored_hosts_str = ', '.join(ignored_hosts)
msg = _('Host filter ignoring hosts: %s')
LOG.debug(msg % ignored_hosts_str)
def _match_forced_hosts(host_map, hosts_to_force):
forced_hosts = []
for (hostname, nodename) in host_map.keys():
if hostname not in hosts_to_force:
del host_map[(hostname, nodename)]
else:
forced_hosts.append(hostname)
if host_map:
forced_hosts_str = ', '.join(forced_hosts)
msg = _('Host filter forcing available hosts to %s')
else:
forced_hosts_str = ', '.join(hosts_to_force)
msg = _("No hosts matched due to not matching "
"'force_hosts' value of '%s'")
LOG.debug(msg % forced_hosts_str)
def _match_forced_nodes(host_map, nodes_to_force):
forced_nodes = []
for (hostname, nodename) in host_map.keys():
if nodename not in nodes_to_force:
del host_map[(hostname, nodename)]
else:
forced_nodes.append(nodename)
if host_map:
forced_nodes_str = ', '.join(forced_nodes)
msg = _('Host filter forcing available nodes to %s')
else:
forced_nodes_str = ', '.join(nodes_to_force)
msg = _("No nodes matched due to not matching "
"'force_nodes' value of '%s'")
LOG.debug(msg % forced_nodes_str)
filter_classes = self._choose_host_filters(filter_class_names)
ignore_hosts = filter_properties.get('ignore_hosts', [])
force_hosts = filter_properties.get('force_hosts', [])
force_nodes = filter_properties.get('force_nodes', [])
if ignore_hosts or force_hosts or force_nodes:
# NOTE(deva): we can't assume "host" is unique because
# one host may have many nodes.
name_to_cls_map = dict([((x.host, x.nodename), x) for x in hosts])
if ignore_hosts:
_strip_ignore_hosts(name_to_cls_map, ignore_hosts)
if not name_to_cls_map:
return []
# NOTE(deva): allow force_hosts and force_nodes independently
if force_hosts:
_match_forced_hosts(name_to_cls_map, force_hosts)
if force_nodes:
_match_forced_nodes(name_to_cls_map, force_nodes)
if force_hosts or force_nodes:
# NOTE(deva): Skip filters when forcing host or node
if name_to_cls_map:
return name_to_cls_map.values()
hosts = name_to_cls_map.itervalues()
return self.filter_handler.get_filtered_objects(filter_classes,
hosts, filter_properties)
def get_weighed_hosts(self, hosts, weight_properties):
"""Weigh the hosts."""
return self.weight_handler.get_weighed_objects(self.weight_classes,
hosts, weight_properties)
def update_service_capabilities(self, service_name, host, capabilities):
"""Update the per-service capabilities based on this notification."""
if service_name != 'compute':
LOG.debug(_('Ignoring %(service_name)s service update '
'from %(host)s'), {'service_name': service_name,
'host': host})
return
state_key = (host, capabilities.get('hypervisor_hostname'))
LOG.debug(_("Received %(service_name)s service update from "
"%(state_key)s."), {'service_name': service_name,
'state_key': state_key})
# Copy the capabilities, so we don't modify the original dict
capab_copy = dict(capabilities)
capab_copy["timestamp"] = timeutils.utcnow() # Reported time
self.service_states[state_key] = capab_copy
def get_all_host_states(self, context):
"""Returns a list of HostStates that represents all the hosts
the HostManager knows about. Also, each of the consumable resources
in HostState are pre-populated and adjusted based on data in the db.
"""
# Get resource usage across the available compute nodes:
compute_nodes = db.compute_node_get_all(context)
seen_nodes = set()
for compute in compute_nodes:
service = compute['service']
if not service:
LOG.warn(_("No service for compute ID %s") % compute['id'])
continue
host = service['host']
node = compute.get('hypervisor_hostname')
state_key = (host, node)
capabilities = self.service_states.get(state_key, None)
host_state = self.host_state_map.get(state_key)
if host_state:
host_state.update_capabilities(capabilities,
dict(service.iteritems()))
else:
host_state = self.host_state_cls(host, node,
capabilities=capabilities,
service=dict(service.iteritems()))
self.host_state_map[state_key] = host_state
host_state.update_from_compute_node(compute)
seen_nodes.add(state_key)
# remove compute nodes from host_state_map if they are not active
dead_nodes = set(self.host_state_map.keys()) - seen_nodes
for state_key in dead_nodes:
host, node = state_key
LOG.info(_("Removing dead compute node %(host)s:%(node)s "
"from scheduler") % {'host': host, 'node': node})
del self.host_state_map[state_key]
return self.host_state_map.itervalues()