manila/manila/scheduler/host_manager.py

287 lines
10 KiB
Python

# Copyright (c) 2011 OpenStack, LLC.
# 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
import six
from manila import db
from manila import exception
from manila.openstack.common import log as logging
from manila.openstack.common.scheduler import filters
from manila.openstack.common.scheduler import weights
from manila.openstack.common import timeutils
from manila import utils
host_manager_opts = [
cfg.ListOpt('scheduler_default_filters',
default=[
'AvailabilityZoneFilter',
'CapacityFilter',
'CapabilitiesFilter'
],
help='Which filter class names to use for filtering hosts '
'when not specified in the request.'),
cfg.ListOpt('scheduler_default_weighers',
default=[
'CapacityWeigher'
],
help='Which weigher 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."""
def __init__(self, host, capabilities=None, service=None):
self.host = host
self.update_capabilities(capabilities, service)
self.share_backend_name = None
self.vendor_name = None
self.driver_version = 0
self.storage_protocol = None
self.QoS_support = False
# Mutable available resources.
# These will change as resources are virtually "consumed".
self.total_capacity_gb = 0
self.free_capacity_gb = None
self.reserved_percentage = 0
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_share_capability(self, capability):
"""Update information about a host from its volume_node info."""
if capability:
if self.updated and self.updated > capability['timestamp']:
return
self.share_backend = capability.get('share_backend_name', None)
self.vendor_name = capability.get('vendor_name', None)
self.driver_version = capability.get('driver_version', None)
self.storage_protocol = capability.get('storage_protocol', None)
self.QoS_support = capability.get('QoS_support', False)
self.total_capacity_gb = capability['total_capacity_gb']
self.free_capacity_gb = capability['free_capacity_gb']
self.reserved_percentage = capability['reserved_percentage']
self.updated = capability['timestamp']
def consume_from_share(self, share):
"""Incrementally update host state from an share."""
share_gb = share['size']
if self.free_capacity_gb == 'infinite':
# There's virtually infinite space on back-end
pass
elif self.free_capacity_gb == 'unknown':
# Unable to determine the actual free space on back-end
pass
else:
self.free_capacity_gb -= share_gb
self.updated = timeutils.utcnow()
class HostManager(object):
"""Base HostManager class."""
host_state_cls = HostState
def __init__(self):
self.service_states = {} # { <host>: {<service>: {cap k : v}}}
self.host_state_map = {}
self.filter_handler = filters.HostFilterHandler('manila.scheduler.'
'filters')
self.filter_classes = self.filter_handler.get_all_classes()
self.weight_handler = weights.HostWeightHandler('manila.scheduler.'
'weights')
self.weight_classes = self.weight_handler.get_all_classes()
def _choose_host_filters(self, filter_cls_names):
"""Choose acceptable filters.
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:
found_class = True
good_filters.append(cls)
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 _choose_host_weighers(self, weight_cls_names):
"""Choose acceptable weighers.
Since the caller may specify which weighers to use, we need to
have an authoritative list of what is permissible. This
function checks the weigher names against a predefined set of
acceptable weighers.
"""
if weight_cls_names is None:
weight_cls_names = CONF.scheduler_default_weighers
if not isinstance(weight_cls_names, (list, tuple)):
weight_cls_names = [weight_cls_names]
good_weighers = []
bad_weighers = []
for weigher_name in weight_cls_names:
found_class = False
for cls in self.weight_classes:
if cls.__name__ == weigher_name:
good_weighers.append(cls)
found_class = True
break
if not found_class:
bad_weighers.append(weigher_name)
if bad_weighers:
msg = ", ".join(bad_weighers)
raise exception.SchedulerHostWeigherNotFound(weigher_name=msg)
return good_weighers
def get_filtered_hosts(self, hosts, filter_properties,
filter_class_names=None):
"""Filter hosts and return only ones passing all filters."""
filter_classes = self._choose_host_filters(filter_class_names)
return self.filter_handler.get_filtered_objects(filter_classes,
hosts,
filter_properties)
def get_weighed_hosts(self, hosts, weight_properties,
weigher_class_names=None):
"""Weigh the hosts."""
weigher_classes = self._choose_host_weighers(weigher_class_names)
return self.weight_handler.get_weighed_objects(weigher_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 not in ('share'):
LOG.debug('Ignoring %(service_name)s service update '
'from %(host)s', locals())
return
LOG.debug("Received %(service_name)s service update from "
"%(host)s." % {"service_name": service_name, "host": host})
# 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[host] = capab_copy
def get_all_host_states_share(self, context):
"""Get all hosts and their states.
Returns a dict of 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.
For example:
{'192.168.1.100': HostState(), ...}
"""
# Get resource usage across the available share nodes:
topic = CONF.share_topic
share_services = db.service_get_all_by_topic(context, topic)
for service in share_services:
if not utils.service_is_up(service) or service['disabled']:
LOG.warn(_("service is down or disabled."))
continue
host = service['host']
capabilities = self.service_states.get(host, None)
host_state = self.host_state_map.get(host)
if host_state:
# copy capabilities to host_state.capabilities
host_state.update_capabilities(capabilities,
dict(six.iteritems(service)))
else:
host_state = self.host_state_cls(
host,
capabilities=capabilities,
service=dict(six.iteritems(service)))
self.host_state_map[host] = host_state
# update host_state
host_state.update_from_share_capability(capabilities)
return self.host_state_map.itervalues()