From ba0ac2e0e2f7ddf71caf6dcc6978e96962bfd08b Mon Sep 17 00:00:00 2001 From: Stephen Mulcahy Date: Wed, 27 Nov 2013 10:26:03 +0000 Subject: [PATCH] Add chance weigher to scheduler Adds chance weigher to scheduler to allow distribution of requests randomly between a number of volume managers. Change-Id: I3f652caf200c406965b52b94cebb244d3bc1779a --- cinder/scheduler/weights/chance.py | 28 ++++++++ .../tests/scheduler/test_capacity_weigher.py | 5 +- cinder/tests/scheduler/test_chance_weigher.py | 71 +++++++++++++++++++ setup.cfg | 1 + 4 files changed, 103 insertions(+), 2 deletions(-) create mode 100644 cinder/scheduler/weights/chance.py create mode 100644 cinder/tests/scheduler/test_chance_weigher.py diff --git a/cinder/scheduler/weights/chance.py b/cinder/scheduler/weights/chance.py new file mode 100644 index 00000000000..4e79b79a2c8 --- /dev/null +++ b/cinder/scheduler/weights/chance.py @@ -0,0 +1,28 @@ +# Copyright (C) 2013 Hewlett-Packard Development Company, L.P. +# +# 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. +""" +Chance Weigher. Assign random weights to hosts. + +Used to spread volumes randomly across a list of equally suitable hosts. +""" + + +import random + +from cinder.openstack.common.scheduler import weights + + +class ChanceWeigher(weights.BaseHostWeigher): + def _weigh_object(self, host_state, weight_properties): + return random.random() diff --git a/cinder/tests/scheduler/test_capacity_weigher.py b/cinder/tests/scheduler/test_capacity_weigher.py index 24b93cca781..f76aaafbfdb 100644 --- a/cinder/tests/scheduler/test_capacity_weigher.py +++ b/cinder/tests/scheduler/test_capacity_weigher.py @@ -20,6 +20,8 @@ import testtools from cinder import context from cinder.openstack.common.scheduler.weights import HostWeightHandler + +from cinder.scheduler.weights.capacity import CapacityWeigher from cinder import test from cinder.tests.scheduler import fakes from cinder.tests import utils as test_utils @@ -30,12 +32,11 @@ class CapacityWeigherTestCase(test.TestCase): super(CapacityWeigherTestCase, self).setUp() self.host_manager = fakes.FakeHostManager() self.weight_handler = HostWeightHandler('cinder.scheduler.weights') - self.weight_classes = self.weight_handler.get_all_classes() 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, + return self.weight_handler.get_weighed_objects([CapacityWeigher], hosts, weight_properties)[0] diff --git a/cinder/tests/scheduler/test_chance_weigher.py b/cinder/tests/scheduler/test_chance_weigher.py new file mode 100644 index 00000000000..4c6b448f17d --- /dev/null +++ b/cinder/tests/scheduler/test_chance_weigher.py @@ -0,0 +1,71 @@ +# Copyright (C) 2013 Hewlett-Packard Development Company, L.P. +# +# 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 Chance Weigher. +""" + +import random +import testtools + +from oslo.config import cfg + +from cinder import context +from cinder.scheduler import host_manager +from cinder.scheduler.weights.chance import ChanceWeigher +from cinder import test +from cinder.tests import utils as test_utils + + +class ChanceWeigherTestCase(test.TestCase): + def setUp(self): + super(ChanceWeigherTestCase, self).setUp() + + def fake_random(self, reset=False): + if reset: + self.not_random_float = 0.0 + else: + self.not_random_float += 1.0 + return self.not_random_float + + def test_chance_weigher(self): + # stub random.random() to verify the ChanceWeigher + # is using random.random() (repeated calls to weigh should + # return incrementing weights) + weigher = ChanceWeigher() + self.stubs.Set(random, 'random', self.fake_random) + self.fake_random(reset=True) + host_state = {'host': 'host.example.com', 'free_capacity_gb': 99999} + weight = weigher._weigh_object(host_state, None) + self.assertEquals(1.0, weight) + weight = weigher._weigh_object(host_state, None) + self.assertEquals(2.0, weight) + weight = weigher._weigh_object(host_state, None) + self.assertEquals(3.0, weight) + + def test_host_manager_choosing_chance_weigher(self): + # ensure HostManager can load the ChanceWeigher + # via the entry points mechanism + hm = host_manager.HostManager() + weighers = hm._choose_host_weighers('ChanceWeigher') + self.assertEquals(1, len(weighers)) + self.assertEquals(weighers[0], ChanceWeigher) + + def test_use_of_chance_weigher_via_host_manager(self): + # ensure we don't lose any hosts when weighing with + # the ChanceWeigher + hm = host_manager.HostManager() + fake_hosts = [host_manager.HostState('fake_host%s' % x) + for x in xrange(1, 5)] + weighed_hosts = hm.get_weighed_hosts(fake_hosts, {}, 'ChanceWeigher') + self.assertEquals(4, len(weighed_hosts)) diff --git a/setup.cfg b/setup.cfg index 8377c21c7e1..883c56c3c59 100644 --- a/setup.cfg +++ b/setup.cfg @@ -47,6 +47,7 @@ cinder.scheduler.filters = RetryFilter = cinder.scheduler.filters.retry_filter:RetryFilter cinder.scheduler.weights = CapacityWeigher = cinder.scheduler.weights.capacity:CapacityWeigher + ChanceWeigher = cinder.scheduler.weights.chance:ChanceWeigher [build_sphinx] all_files = 1