From 2c6ab62ae29811c39e6f0b7f8a8b5a224df28810 Mon Sep 17 00:00:00 2001 From: Chris Behrens Date: Fri, 9 Nov 2012 02:48:09 +0000 Subject: [PATCH] Refactor scheduling weights. This makes scheduling weights more plugin friendly and creates shared code that can be used by the host scheduler as well as the future cells scheduler. Weighing classes can now be specified much like you can specify scheduling host filters. The new weights code reverses the old behavior where lower weights win. Higher weights are now the winners. The least_cost module and configs have been deprecated, but are still supported for backwards compatibility. The code has moved to nova.scheduler.weights.least_cost and been modified to work with the new loadable-class code. If any of the least_cost related config options are specified, this least_cost weigher will be used. For those not overriding the default least_cost config values, the new RamWeigher class will be used. The default behavior of the RamWeigher class is the same default behavior as the old least_cost module. The new weights code introduces a new config option 'scheduler_weight_classes' which is used to specify which weigher classes to use. The default is 'all classes', but modified if least_cost deprecated config options are used, as mentioned above. The RamWeigher class introduces a new config option 'ram_weight_multiplier'. The default of 1.0 causes weights equal to the free memory in MB to be returned, thus hosts with more free memory are preferred (causes equal spreading). Changing this value to a negative number such as -1.0 will cause reverse behavior (fill first). DocImpact Change-Id: I1e5e5039c299db02f7287f2d33299ebf0b9732ce --- nova/scheduler/filter_scheduler.py | 94 +++---------- nova/scheduler/host_manager.py | 12 ++ nova/scheduler/least_cost.py | 118 ---------------- nova/scheduler/weights/__init__.py | 61 +++++++++ nova/scheduler/weights/least_cost.py | 126 ++++++++++++++++++ nova/scheduler/weights/ram.py | 46 +++++++ nova/tests/scheduler/test_filter_scheduler.py | 41 ++---- nova/tests/scheduler/test_least_cost.py | 112 +++++++++++----- nova/tests/scheduler/test_weights.py | 117 ++++++++++++++++ nova/weights.py | 71 ++++++++++ 10 files changed, 543 insertions(+), 255 deletions(-) delete mode 100644 nova/scheduler/least_cost.py create mode 100644 nova/scheduler/weights/__init__.py create mode 100644 nova/scheduler/weights/least_cost.py create mode 100644 nova/scheduler/weights/ram.py create mode 100644 nova/tests/scheduler/test_weights.py create mode 100644 nova/weights.py diff --git a/nova/scheduler/filter_scheduler.py b/nova/scheduler/filter_scheduler.py index 10dc7e37cd1f..636818e59093 100644 --- a/nova/scheduler/filter_scheduler.py +++ b/nova/scheduler/filter_scheduler.py @@ -19,16 +19,11 @@ You can customize this scheduler by specifying your own Host Filters and Weighing Functions. """ -import operator - from nova import config from nova import exception -from nova import flags -from nova.openstack.common import importutils from nova.openstack.common import log as logging from nova.openstack.common.notifier import api as notifier from nova.scheduler import driver -from nova.scheduler import least_cost from nova.scheduler import scheduler_options CONF = config.CONF @@ -61,7 +56,7 @@ class FilterScheduler(driver.Scheduler): notifier.notify(context, notifier.publisher_id("scheduler"), 'scheduler.run_instance.start', notifier.INFO, payload) - weighted_hosts = self._schedule(context, request_spec, + weighed_hosts = self._schedule(context, request_spec, filter_properties, instance_uuids) # NOTE(comstud): Make sure we do not pass this through. It @@ -73,11 +68,11 @@ class FilterScheduler(driver.Scheduler): try: try: - weighted_host = weighted_hosts.pop(0) + weighed_host = weighed_hosts.pop(0) except IndexError: raise exception.NoValidHost(reason="") - self._provision_resource(context, weighted_host, + self._provision_resource(context, weighed_host, request_spec, filter_properties, requested_networks, @@ -107,29 +102,29 @@ class FilterScheduler(driver.Scheduler): the prep_resize operation to it. """ - hosts = self._schedule(context, request_spec, filter_properties, - [instance['uuid']]) - if not hosts: + weighed_hosts = self._schedule(context, request_spec, + filter_properties, [instance['uuid']]) + if not weighed_hosts: raise exception.NoValidHost(reason="") - host = hosts.pop(0) + weighed_host = weighed_hosts.pop(0) self._post_select_populate_filter_properties(filter_properties, - host.host_state) + weighed_host.obj) # context is not serializable filter_properties.pop('context', None) # Forward off to the host self.compute_rpcapi.prep_resize(context, image, instance, - instance_type, host.host_state.host, reservations, + instance_type, weighed_host.obj.host, reservations, request_spec=request_spec, filter_properties=filter_properties) - def _provision_resource(self, context, weighted_host, request_spec, + def _provision_resource(self, context, weighed_host, request_spec, filter_properties, requested_networks, injected_files, admin_password, is_first_time, instance_uuid=None): """Create the requested resource in this Zone.""" payload = dict(request_spec=request_spec, - weighted_host=weighted_host.to_dict(), + weighted_host=weighed_host.to_dict(), instance_id=instance_uuid) notifier.notify(context, notifier.publisher_id("scheduler"), 'scheduler.run_instance.scheduled', notifier.INFO, @@ -137,15 +132,15 @@ class FilterScheduler(driver.Scheduler): # TODO(NTTdocomo): Combine the next two updates into one driver.db_instance_node_set(context, - instance_uuid, weighted_host.host_state.nodename) + instance_uuid, weighed_host.obj.nodename) updated_instance = driver.instance_update_db(context, instance_uuid) self._post_select_populate_filter_properties(filter_properties, - weighted_host.host_state) + weighed_host.obj) self.compute_rpcapi.run_instance(context, instance=updated_instance, - host=weighted_host.host_state.host, + host=weighed_host.obj.host, request_spec=request_spec, filter_properties=filter_properties, requested_networks=requested_networks, injected_files=injected_files, @@ -232,7 +227,6 @@ class FilterScheduler(driver.Scheduler): instance_properties = request_spec['instance_properties'] instance_type = request_spec.get("instance_type", None) - cost_functions = self.get_cost_functions() config_options = self._get_configuration_options() # check retry policy. Rather ugly use of instance_uuids[0]... @@ -276,60 +270,12 @@ class FilterScheduler(driver.Scheduler): LOG.debug(_("Filtered %(hosts)s") % locals()) - # weighted_host = WeightedHost() ... the best - # host for the job. - # TODO(comstud): filter_properties will also be used for - # weighing and I plan fold weighing into the host manager - # in a future patch. I'll address the naming of this - # variable at that time. - weighted_host = least_cost.weighted_sum(cost_functions, - hosts, filter_properties) - LOG.debug(_("Weighted %(weighted_host)s") % locals()) - selected_hosts.append(weighted_host) - + weighed_hosts = self.host_manager.get_weighed_hosts(hosts, + filter_properties) + best_host = weighed_hosts[0] + LOG.debug(_("Choosing host %(best_host)s") % locals()) + selected_hosts.append(best_host) # Now consume the resources so the filter/weights # will change for the next instance. - weighted_host.host_state.consume_from_instance( - instance_properties) - - selected_hosts.sort(key=operator.attrgetter('weight')) + best_host.obj.consume_from_instance(instance_properties) return selected_hosts - - def get_cost_functions(self): - """Returns a list of tuples containing weights and cost functions to - use for weighing hosts - """ - if self.cost_function_cache is not None: - return self.cost_function_cache - - cost_fns = [] - for cost_fn_str in CONF.least_cost_functions: - if '.' in cost_fn_str: - short_name = cost_fn_str.split('.')[-1] - else: - short_name = cost_fn_str - cost_fn_str = "%s.%s.%s" % ( - __name__, self.__class__.__name__, short_name) - if not (short_name.startswith('compute_') or - short_name.startswith('noop')): - continue - - try: - # NOTE: import_class is somewhat misnamed since - # the weighing function can be any non-class callable - # (i.e., no 'self') - cost_fn = importutils.import_class(cost_fn_str) - except ImportError: - raise exception.SchedulerCostFunctionNotFound( - cost_fn_str=cost_fn_str) - - try: - flag_name = "%s_weight" % cost_fn.__name__ - weight = getattr(CONF, flag_name) - except AttributeError: - raise exception.SchedulerWeightFlagNotFound( - flag_name=flag_name) - cost_fns.append((weight, cost_fn)) - - self.cost_function_cache = cost_fns - return cost_fns diff --git a/nova/scheduler/host_manager.py b/nova/scheduler/host_manager.py index e93b529f9383..ba4fa3d34d0e 100644 --- a/nova/scheduler/host_manager.py +++ b/nova/scheduler/host_manager.py @@ -28,6 +28,7 @@ from nova.openstack.common import cfg 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', @@ -47,6 +48,9 @@ host_manager_opts = [ ], 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 = config.CONF @@ -258,6 +262,9 @@ class HostManager(object): 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 @@ -316,6 +323,11 @@ class HostManager(object): 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.""" diff --git a/nova/scheduler/least_cost.py b/nova/scheduler/least_cost.py deleted file mode 100644 index d3eaee735126..000000000000 --- a/nova/scheduler/least_cost.py +++ /dev/null @@ -1,118 +0,0 @@ -# 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. -""" -Least Cost is an algorithm for choosing which host machines to -provision a set of resources to. The input is a WeightedHost object which -is decided upon by a set of objective-functions, called the 'cost-functions'. -The WeightedHost contains a combined weight for each cost-function. - -The cost-function and weights are tabulated, and the host with the least cost -is then selected for provisioning. -""" - -from nova import config -from nova import flags -from nova.openstack.common import cfg -from nova.openstack.common import log as logging - - -LOG = logging.getLogger(__name__) - -least_cost_opts = [ - cfg.ListOpt('least_cost_functions', - default=[ - 'nova.scheduler.least_cost.compute_fill_first_cost_fn' - ], - help='Which cost functions the LeastCostScheduler should use'), - cfg.FloatOpt('noop_cost_fn_weight', - default=1.0, - help='How much weight to give the noop cost function'), - cfg.FloatOpt('compute_fill_first_cost_fn_weight', - default=-1.0, - help='How much weight to give the fill-first cost function. ' - 'A negative value will reverse behavior: ' - 'e.g. spread-first'), - ] - -CONF = config.CONF -CONF.register_opts(least_cost_opts) - -# TODO(sirp): Once we have enough of these rules, we can break them out into a -# cost_functions.py file (perhaps in a least_cost_scheduler directory) - - -class WeightedHost(object): - """Reduced set of information about a host that has been weighed. - This is an attempt to remove some of the ad-hoc dict structures - previously used.""" - - def __init__(self, weight, host_state=None): - self.weight = weight - self.host_state = host_state - - def to_dict(self): - x = dict(weight=self.weight) - if self.host_state: - x['host'] = self.host_state.host - return x - - def __repr__(self): - if self.host_state: - return "WeightedHost host: %s" % self.host_state.host - return "WeightedHost with no host_state" - - -def noop_cost_fn(host_state, weighing_properties): - """Return a pre-weight cost of 1 for each host""" - return 1 - - -def compute_fill_first_cost_fn(host_state, weighing_properties): - """More free ram = higher weight. So servers with less free - ram will be preferred. - - Note: the weight for this function in default configuration - is -1.0. With a -1.0 this function runs in reverse, so systems - with the most free memory will be preferred. - """ - return host_state.free_ram_mb - - -def weighted_sum(weighted_fns, host_states, weighing_properties): - """Use the weighted-sum method to compute a score for an array of objects. - - Normalize the results of the objective-functions so that the weights are - meaningful regardless of objective-function's range. - - :param host_list: ``[(host, HostInfo()), ...]`` - :param weighted_fns: list of weights and functions like:: - - [(weight, objective-functions), ...] - - :param weighing_properties: an arbitrary dict of values that can - influence weights. - - :returns: a single WeightedHost object which represents the best - candidate. - """ - - min_score, best_host = None, None - for host_state in host_states: - score = sum(weight * fn(host_state, weighing_properties) - for weight, fn in weighted_fns) - if min_score is None or score < min_score: - min_score, best_host = score, host_state - - return WeightedHost(min_score, host_state=best_host) diff --git a/nova/scheduler/weights/__init__.py b/nova/scheduler/weights/__init__.py new file mode 100644 index 000000000000..55c44b5289c9 --- /dev/null +++ b/nova/scheduler/weights/__init__.py @@ -0,0 +1,61 @@ +# 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. + +""" +Scheduler host weights +""" + + +from nova import config +from nova.openstack.common import log as logging +from nova.scheduler.weights import least_cost +from nova import weights + +LOG = logging.getLogger(__name__) +CONF = config.CONF + + +class WeighedHost(weights.WeighedObject): + def to_dict(self): + x = dict(weight=self.weight) + x['host'] = self.obj.host + return x + + def __repr__(self): + return "WeighedHost [host: %s, weight: %s]" % ( + self.obj.host, self.weight) + + +class BaseHostWeigher(weights.BaseWeigher): + """Base class for host weights.""" + pass + + +class HostWeightHandler(weights.BaseWeightHandler): + object_class = WeighedHost + + def __init__(self): + super(HostWeightHandler, self).__init__(BaseHostWeigher) + + +def all_weighers(): + """Return a list of weight plugin classes found in this directory.""" + + if (CONF.least_cost_functions is not None or + CONF.compute_fill_first_cost_fn_weight is not None): + LOG.deprecated(_('least_cost has been deprecated in favor of ' + 'the RAM Weigher.')) + return least_cost.get_least_cost_weighers() + return HostWeightHandler().get_all_classes() diff --git a/nova/scheduler/weights/least_cost.py b/nova/scheduler/weights/least_cost.py new file mode 100644 index 000000000000..2d886f4612ea --- /dev/null +++ b/nova/scheduler/weights/least_cost.py @@ -0,0 +1,126 @@ +# Copyright (c) 2011-2012 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. +""" +Least Cost is an algorithm for choosing which host machines to +provision a set of resources to. The input is a WeightedHost object which +is decided upon by a set of objective-functions, called the 'cost-functions'. +The WeightedHost contains a combined weight for each cost-function. + +The cost-function and weights are tabulated, and the host with the least cost +is then selected for provisioning. + +NOTE(comstud): This is deprecated. One should use the RAMWeigher and/or +create other weight modules. +""" + +from nova import config +from nova import exception +from nova.openstack.common import cfg +from nova.openstack.common import importutils +from nova.openstack.common import log as logging + + +LOG = logging.getLogger(__name__) + +least_cost_opts = [ + cfg.ListOpt('least_cost_functions', + default=None, + help='Which cost functions the LeastCostScheduler should use'), + cfg.FloatOpt('noop_cost_fn_weight', + default=1.0, + help='How much weight to give the noop cost function'), + cfg.FloatOpt('compute_fill_first_cost_fn_weight', + default=None, + help='How much weight to give the fill-first cost function. ' + 'A negative value will reverse behavior: ' + 'e.g. spread-first'), + ] + +CONF = config.CONF +CONF.register_opts(least_cost_opts) + + +def noop_cost_fn(host_state, weight_properties): + """Return a pre-weight cost of 1 for each host""" + return 1 + + +def compute_fill_first_cost_fn(host_state, weight_properties): + """Higher weights win, so we should return a lower weight + when there's more free ram available. + + Note: the weight modifier for this function in default configuration + is -1.0. With -1.0 this function runs in reverse, so systems + with the most free memory will be preferred. + """ + return -host_state.free_ram_mb + + +def _get_cost_functions(): + """Returns a list of tuples containing weights and cost functions to + use for weighing hosts + """ + cost_fns_conf = CONF.least_cost_functions + if cost_fns_conf is None: + # The old default. This will get fixed up below. + fn_str = 'nova.scheduler.least_cost.compute_fill_first_cost_fn' + cost_fns_conf = [fn_str] + cost_fns = [] + for cost_fn_str in cost_fns_conf: + short_name = cost_fn_str.split('.')[-1] + if not (short_name.startswith('compute_') or + short_name.startswith('noop')): + continue + # Fix up any old paths to the new paths + if cost_fn_str.startswith('nova.scheduler.least_cost.'): + cost_fn_str = ('nova.scheduler.weights.least_cost' + + cost_fn_str[25:]) + try: + # NOTE: import_class is somewhat misnamed since + # the weighing function can be any non-class callable + # (i.e., no 'self') + cost_fn = importutils.import_class(cost_fn_str) + except ImportError: + raise exception.SchedulerCostFunctionNotFound( + cost_fn_str=cost_fn_str) + + try: + flag_name = "%s_weight" % cost_fn.__name__ + weight = getattr(CONF, flag_name) + except AttributeError: + raise exception.SchedulerWeightFlagNotFound( + flag_name=flag_name) + # Set the original default. + if (flag_name == 'compute_fill_first_cost_fn_weight' and + weight is None): + weight = -1.0 + cost_fns.append((weight, cost_fn)) + return cost_fns + + +def get_least_cost_weighers(): + cost_functions = _get_cost_functions() + + # Unfortunately we need to import this late so we don't have an + # import loop. + from nova.scheduler import weights + + class _LeastCostWeigher(weights.BaseHostWeigher): + def weigh_objects(self, weighted_hosts, weight_properties): + for host in weighted_hosts: + host.weight = sum(weight * fn(host.obj, weight_properties) + for weight, fn in cost_functions) + + return [_LeastCostWeigher] diff --git a/nova/scheduler/weights/ram.py b/nova/scheduler/weights/ram.py new file mode 100644 index 000000000000..0fe1911c4cf0 --- /dev/null +++ b/nova/scheduler/weights/ram.py @@ -0,0 +1,46 @@ +# 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. +""" +RAM Weigher. Weigh hosts by their RAM usage. + +The default is to spread instances across all hosts evenly. If you prefer +stacking, you can set the 'ram_weight_multiplier' option to a negative +number and the weighing has the opposite effect of the default. +""" + +from nova import config +from nova.openstack.common import cfg +from nova.scheduler import weights + + +ram_weight_opts = [ + cfg.FloatOpt('ram_weight_multiplier', + default=1.0, + help='Multiplier used for weighing ram. Negative ' + 'numbers mean to stack vs spread.'), +] + +CONF = config.CONF +CONF.register_opts(ram_weight_opts) + + +class RAMWeigher(weights.BaseHostWeigher): + def _weight_multiplier(self): + """Override the weight multiplier.""" + return CONF.ram_weight_multiplier + + def _weigh_object(self, host_state, weight_properties): + """Higher weights win. We want spreading to be the default.""" + return host_state.free_ram_mb diff --git a/nova/tests/scheduler/test_filter_scheduler.py b/nova/tests/scheduler/test_filter_scheduler.py index b8ab45bc246a..e9412ba6006f 100644 --- a/nova/tests/scheduler/test_filter_scheduler.py +++ b/nova/tests/scheduler/test_filter_scheduler.py @@ -27,7 +27,7 @@ from nova import exception from nova.scheduler import driver from nova.scheduler import filter_scheduler from nova.scheduler import host_manager -from nova.scheduler import least_cost +from nova.scheduler import weights from nova.tests.scheduler import fakes from nova.tests.scheduler import test_scheduler @@ -145,11 +145,10 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase): self.next_weight = 1.0 - def _fake_weighted_sum(functions, hosts, options): + def _fake_weigh_objects(_self, functions, hosts, options): self.next_weight += 2.0 host_state = hosts[0] - return least_cost.WeightedHost(self.next_weight, - host_state=host_state) + return [weights.WeighedHost(host_state, self.next_weight)] sched = fakes.FakeFilterScheduler() fake_context = context.RequestContext('user', 'project', @@ -157,7 +156,8 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase): self.stubs.Set(sched.host_manager, 'get_filtered_hosts', fake_get_filtered_hosts) - self.stubs.Set(least_cost, 'weighted_sum', _fake_weighted_sum) + self.stubs.Set(weights.HostWeightHandler, + 'get_weighed_objects', _fake_weigh_objects) fakes.mox_host_manager_db_calls(self.mox, fake_context) request_spec = {'num_instances': 10, @@ -171,10 +171,10 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase): 'vcpus': 1, 'os_type': 'Linux'}} self.mox.ReplayAll() - weighted_hosts = sched._schedule(fake_context, request_spec, {}) - self.assertEquals(len(weighted_hosts), 10) - for weighted_host in weighted_hosts: - self.assertTrue(weighted_host.host_state is not None) + weighed_hosts = sched._schedule(fake_context, request_spec, {}) + self.assertEquals(len(weighed_hosts), 10) + for weighed_host in weighed_hosts: + self.assertTrue(weighed_host.obj is not None) def test_schedule_prep_resize_doesnt_update_host(self): fake_context = context.RequestContext('user', 'project', @@ -184,7 +184,7 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase): def _return_hosts(*args, **kwargs): host_state = host_manager.HostState('host2', 'node2') - return [least_cost.WeightedHost(1.0, host_state=host_state)] + return [weights.WeighedHost(host_state, 1.0)] self.stubs.Set(sched, '_schedule', _return_hosts) @@ -203,19 +203,6 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase): instance, {}, None) self.assertEqual(info['called'], 0) - def test_get_cost_functions(self): - fixture = fakes.FakeFilterScheduler() - fns = fixture.get_cost_functions() - self.assertEquals(len(fns), 1) - weight, fn = fns[0] - self.assertEquals(weight, -1.0) - hostinfo = host_manager.HostState('host', 'node') - hostinfo.update_from_compute_node(dict(memory_mb=1000, - local_gb=0, vcpus=1, disk_available_least=1000, - free_disk_mb=1000, free_ram_mb=872, vcpus_used=0, - local_gb_used=0, updated_at=None)) - self.assertEquals(872, fn(hostinfo, {})) - def test_max_attempts(self): self.flags(scheduler_max_attempts=4) @@ -332,14 +319,14 @@ class FilterSchedulerTestCase(test_scheduler.SchedulerTestCase): reservations = None host = fakes.FakeHostState('host', 'node', {}) - weighted_host = least_cost.WeightedHost(1, host) - hosts = [weighted_host] + weighed_host = weights.WeighedHost(host, 1) + weighed_hosts = [weighed_host] self.mox.StubOutWithMock(sched, '_schedule') self.mox.StubOutWithMock(sched.compute_rpcapi, 'prep_resize') - sched._schedule(self.context, request_spec, - filter_properties, [instance['uuid']]).AndReturn(hosts) + sched._schedule(self.context, request_spec, filter_properties, + [instance['uuid']]).AndReturn(weighed_hosts) sched.compute_rpcapi.prep_resize(self.context, image, instance, instance_type, 'host', reservations, request_spec=request_spec, filter_properties=filter_properties) diff --git a/nova/tests/scheduler/test_least_cost.py b/nova/tests/scheduler/test_least_cost.py index 1d180d7182c0..f8ed20b43d37 100644 --- a/nova/tests/scheduler/test_least_cost.py +++ b/nova/tests/scheduler/test_least_cost.py @@ -1,4 +1,4 @@ -# Copyright 2011 OpenStack LLC. +# Copyright 2011-2012 OpenStack LLC. # All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); you may @@ -15,27 +15,51 @@ """ Tests For Least Cost functions. """ +from nova import config from nova import context -from nova.scheduler import host_manager -from nova.scheduler import least_cost +from nova.openstack.common import cfg +from nova.scheduler import weights +from nova.scheduler.weights import least_cost from nova import test -from nova.tests import matchers from nova.tests.scheduler import fakes -def offset(hostinfo, options): +test_least_cost_opts = [ + cfg.FloatOpt('compute_fake_weigher1_weight', + default=2.0, + help='How much weight to give the fake_weigher1 function'), + cfg.FloatOpt('compute_fake_weigher2_weight', + default=1.0, + help='How much weight to give the fake_weigher2 function'), + ] + +CONF = config.CONF +CONF.import_opt('least_cost_functions', 'nova.scheduler.weights.least_cost') +CONF.import_opt('compute_fill_first_cost_fn_weight', + 'nova.scheduler.weights.least_cost') +CONF.register_opts(test_least_cost_opts) + + +def compute_fake_weigher1(hostinfo, options): return hostinfo.free_ram_mb + 10000 -def scale(hostinfo, options): +def compute_fake_weigher2(hostinfo, options): return hostinfo.free_ram_mb * 2 class LeastCostTestCase(test.TestCase): def setUp(self): super(LeastCostTestCase, self).setUp() - self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0) self.host_manager = fakes.FakeHostManager() + self.weight_handler = weights.HostWeightHandler() + + def _get_weighed_host(self, hosts, weight_properties=None): + weigher_classes = least_cost.get_least_cost_weighers() + if weight_properties is None: + weight_properties = {} + return self.weight_handler.get_weighed_objects(weigher_classes, + hosts, weight_properties)[0] def _get_all_hosts(self): ctxt = context.get_admin_context() @@ -46,8 +70,39 @@ class LeastCostTestCase(test.TestCase): self.mox.ResetAll() return host_states - def test_weighted_sum_happy_day(self): - fn_tuples = [(1.0, offset), (1.0, scale)] + def test_default_of_spread_first(self): + # Default modifier is -1.0, so it turns out that hosts with + # the most free memory win + hostinfo_list = self._get_all_hosts() + + # host1: free_ram_mb=512 + # host2: free_ram_mb=1024 + # host3: free_ram_mb=3072 + # host4: free_ram_mb=8192 + + # so, host1 should win: + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, 8192) + self.assertEqual(weighed_host.obj.host, 'host4') + + def test_filling_first(self): + self.flags(compute_fill_first_cost_fn_weight=1.0) + hostinfo_list = self._get_all_hosts() + + # host1: free_ram_mb=-512 + # host2: free_ram_mb=-1024 + # host3: free_ram_mb=-3072 + # host4: free_ram_mb=-8192 + + # so, host1 should win: + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, -512) + self.assertEqual(weighed_host.obj.host, 'host1') + + def test_weighted_sum_provided_method(self): + fns = ['nova.tests.scheduler.test_least_cost.compute_fake_weigher1', + 'nova.tests.scheduler.test_least_cost.compute_fake_weigher2'] + self.flags(least_cost_functions=fns) hostinfo_list = self._get_all_hosts() # host1: free_ram_mb=512 @@ -59,18 +114,17 @@ class LeastCostTestCase(test.TestCase): # [10512, 11024, 13072, 18192] # [1024, 2048, 6144, 16384] - # adjusted [ 1.0 * x + 1.0 * y] = - # [11536, 13072, 19216, 34576] + # adjusted [ 2.0 * x + 1.0 * y] = + # [22048, 24096, 32288, 52768] # so, host1 should win: - options = {} - weighted_host = least_cost.weighted_sum(fn_tuples, hostinfo_list, - options) - self.assertEqual(weighted_host.weight, 11536) - self.assertEqual(weighted_host.host_state.host, 'host1') + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, 52768) + self.assertEqual(weighed_host.obj.host, 'host4') def test_weighted_sum_single_function(self): - fn_tuples = [(1.0, offset), ] + fns = ['nova.tests.scheduler.test_least_cost.compute_fake_weigher1'] + self.flags(least_cost_functions=fns) hostinfo_list = self._get_all_hosts() # host1: free_ram_mb=0 @@ -80,24 +134,10 @@ class LeastCostTestCase(test.TestCase): # [offset, ]= # [10512, 11024, 13072, 18192] + # adjusted [ 2.0 * x ]= + # [21024, 22048, 26144, 36384] # so, host1 should win: - options = {} - weighted_host = least_cost.weighted_sum(fn_tuples, hostinfo_list, - options) - self.assertEqual(weighted_host.weight, 10512) - self.assertEqual(weighted_host.host_state.host, 'host1') - - -class TestWeightedHost(test.TestCase): - def test_dict_conversion_without_host_state(self): - host = least_cost.WeightedHost('someweight') - expected = {'weight': 'someweight'} - self.assertThat(host.to_dict(), matchers.DictMatches(expected)) - - def test_dict_conversion_with_host_state(self): - host_state = host_manager.HostState('somehost', None) - host = least_cost.WeightedHost('someweight', host_state) - expected = {'weight': 'someweight', - 'host': 'somehost'} - self.assertThat(host.to_dict(), matchers.DictMatches(expected)) + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, 36384) + self.assertEqual(weighed_host.obj.host, 'host4') diff --git a/nova/tests/scheduler/test_weights.py b/nova/tests/scheduler/test_weights.py new file mode 100644 index 000000000000..8699ed811355 --- /dev/null +++ b/nova/tests/scheduler/test_weights.py @@ -0,0 +1,117 @@ +# Copyright 2011-2012 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. +""" +Tests For Scheduler weights. +""" + +from nova import context +from nova.scheduler import weights +from nova import test +from nova.tests import matchers +from nova.tests.scheduler import fakes + + +class TestWeighedHost(test.TestCase): + def test_dict_conversion(self): + host_state = fakes.FakeHostState('somehost', None, {}) + host = weights.WeighedHost(host_state, 'someweight') + expected = {'weight': 'someweight', + 'host': 'somehost'} + self.assertThat(host.to_dict(), matchers.DictMatches(expected)) + + def test_all_weighers(self): + classes = weights.all_weighers() + class_names = [cls.__name__ for cls in classes] + self.assertEqual(len(classes), 1) + self.assertIn('RAMWeigher', class_names) + + def test_all_weighers_with_deprecated_config1(self): + self.flags(compute_fill_first_cost_fn_weight=-1.0) + classes = weights.all_weighers() + class_names = [cls.__name__ for cls in classes] + self.assertEqual(len(classes), 1) + self.assertIn('_LeastCostWeigher', class_names) + + def test_all_weighers_with_deprecated_config2(self): + self.flags(least_cost_functions=['something']) + classes = weights.all_weighers() + class_names = [cls.__name__ for cls in classes] + self.assertEqual(len(classes), 1) + self.assertIn('_LeastCostWeigher', class_names) + + +class RamWeigherTestCase(test.TestCase): + def setUp(self): + super(RamWeigherTestCase, self).setUp() + self.host_manager = fakes.FakeHostManager() + self.weight_handler = weights.HostWeightHandler() + self.weight_classes = self.weight_handler.get_matching_classes( + ['nova.scheduler.weights.ram.RAMWeigher']) + + def _get_weighed_host(self, hosts, weight_properties=None): + if weight_properties is None: + weight_properties = {} + return self.weight_handler.get_weighed_objects(self.weight_classes, + hosts, weight_properties)[0] + + def _get_all_hosts(self): + ctxt = context.get_admin_context() + fakes.mox_host_manager_db_calls(self.mox, ctxt) + self.mox.ReplayAll() + host_states = self.host_manager.get_all_host_states(ctxt) + self.mox.VerifyAll() + self.mox.ResetAll() + return host_states + + def test_default_of_spreading_first(self): + hostinfo_list = self._get_all_hosts() + + # host1: free_ram_mb=512 + # host2: free_ram_mb=1024 + # host3: free_ram_mb=3072 + # host4: free_ram_mb=8192 + + # so, host4 should win: + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, 8192) + self.assertEqual(weighed_host.obj.host, 'host4') + + def test_ram_filter_multiplier1(self): + self.flags(ram_weight_multiplier=-1.0) + hostinfo_list = self._get_all_hosts() + + # host1: free_ram_mb=-512 + # host2: free_ram_mb=-1024 + # host3: free_ram_mb=-3072 + # host4: free_ram_mb=-8192 + + # so, host1 should win: + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, -512) + self.assertEqual(weighed_host.obj.host, 'host1') + + def test_ram_filter_multiplier2(self): + self.flags(ram_weight_multiplier=2.0) + hostinfo_list = self._get_all_hosts() + + # host1: free_ram_mb=512 * 2 + # host2: free_ram_mb=1024 * 2 + # host3: free_ram_mb=3072 * 2 + # host4: free_ram_mb=8192 * 2 + + # so, host4 should win: + weighed_host = self._get_weighed_host(hostinfo_list) + self.assertEqual(weighed_host.weight, 8192 * 2) + self.assertEqual(weighed_host.obj.host, 'host4') diff --git a/nova/weights.py b/nova/weights.py new file mode 100644 index 000000000000..981171b3e371 --- /dev/null +++ b/nova/weights.py @@ -0,0 +1,71 @@ +# Copyright (c) 2011-2012 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. + +""" +Pluggable Weighing support +""" + +from nova import loadables + + +class WeighedObject(object): + """Object with weight information.""" + def __init__(self, obj, weight): + self.obj = obj + self.weight = weight + + def __repr__(self): + return "" % (self.obj, self.weight) + + +class BaseWeigher(object): + """Base class for pluggable weighers.""" + def _weight_multiplier(self): + """How weighted this weigher should be. Normally this would + be overriden in a subclass based on a config value. + """ + return 1.0 + + def _weigh_object(self, obj, weight_properties): + """Override in a subclass to specify a weight for a specific + object. + """ + return 0.0 + + def weigh_objects(self, weighed_obj_list, weight_properties): + """Weigh multiple objects. Override in a subclass if you need + need access to all objects in order to manipulate weights. + """ + for obj in weighed_obj_list: + obj.weight += (self._weight_multiplier() * + self._weigh_object(obj.obj, weight_properties)) + + +class BaseWeightHandler(loadables.BaseLoader): + object_class = WeighedObject + + def get_weighed_objects(self, weigher_classes, obj_list, + weighing_properties): + """Return a sorted (highest score first) list of WeighedObjects.""" + + if not obj_list: + return [] + + weighed_objs = [self.object_class(obj, 0.0) for obj in obj_list] + for weigher_cls in weigher_classes: + weigher = weigher_cls() + weigher.weigh_objects(weighed_objs, weighing_properties) + + return sorted(weighed_objs, key=lambda x: x.weight, reverse=True)