141 lines
4.6 KiB
Python
141 lines
4.6 KiB
Python
# Copyright 2011 OpenStack LLC.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""
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Tests For Least Cost Scheduler
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"""
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from nova import test
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from nova.scheduler import least_cost
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from nova.tests.scheduler import test_abstract_scheduler
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MB = 1024 * 1024
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class FakeHost(object):
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def __init__(self, host_id, free_ram, io):
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self.id = host_id
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self.free_ram = free_ram
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self.io = io
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class WeightedSumTestCase(test.TestCase):
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def test_empty_domain(self):
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domain = []
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weighted_fns = []
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result = least_cost.weighted_sum(domain, weighted_fns)
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expected = []
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self.assertEqual(expected, result)
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def test_basic_costing(self):
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hosts = [
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FakeHost(1, 512 * MB, 100),
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FakeHost(2, 256 * MB, 400),
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FakeHost(3, 512 * MB, 100),
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]
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weighted_fns = [
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(1, lambda h: h.free_ram), # Fill-first, free_ram is a *cost*
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(2, lambda h: h.io), # Avoid high I/O
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]
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costs = least_cost.weighted_sum(
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domain=hosts, weighted_fns=weighted_fns)
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# Each 256 MB unit of free-ram contributes 0.5 points by way of:
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# cost = weight * (score/max_score) = 1 * (256/512) = 0.5
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# Each 100 iops of IO adds 0.5 points by way of:
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# cost = 2 * (100/400) = 2 * 0.25 = 0.5
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expected = [1.5, 2.5, 1.5]
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self.assertEqual(expected, costs)
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class LeastCostSchedulerTestCase(test.TestCase):
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def setUp(self):
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super(LeastCostSchedulerTestCase, self).setUp()
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class FakeZoneManager:
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pass
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zone_manager = FakeZoneManager()
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states = test_abstract_scheduler.fake_zone_manager_service_states(
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num_hosts=10)
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zone_manager.service_states = states
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self.sched = least_cost.LeastCostScheduler()
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self.sched.zone_manager = zone_manager
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def tearDown(self):
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super(LeastCostSchedulerTestCase, self).tearDown()
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def assertWeights(self, expected, num, request_spec, hosts):
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weighted = self.sched.weigh_hosts(num, request_spec, hosts)
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self.assertDictListMatch(weighted, expected, approx_equal=True)
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def test_no_hosts(self):
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num = 1
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request_spec = {}
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hosts = []
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expected = []
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self.assertWeights(expected, num, request_spec, hosts)
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def test_noop_cost_fn(self):
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self.flags(least_cost_scheduler_cost_functions=[
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'nova.scheduler.least_cost.noop_cost_fn'],
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noop_cost_fn_weight=1)
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num = 1
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request_spec = {}
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hosts = self.sched.filter_hosts(num, request_spec)
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expected = [dict(weight=1, hostname=hostname)
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for hostname, caps in hosts]
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self.assertWeights(expected, num, request_spec, hosts)
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def test_cost_fn_weights(self):
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self.flags(least_cost_scheduler_cost_functions=[
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'nova.scheduler.least_cost.noop_cost_fn'],
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noop_cost_fn_weight=2)
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num = 1
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request_spec = {}
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hosts = self.sched.filter_hosts(num, request_spec)
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expected = [dict(weight=2, hostname=hostname)
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for hostname, caps in hosts]
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self.assertWeights(expected, num, request_spec, hosts)
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def test_compute_fill_first_cost_fn(self):
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self.flags(least_cost_scheduler_cost_functions=[
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'nova.scheduler.least_cost.compute_fill_first_cost_fn'],
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compute_fill_first_cost_fn_weight=1)
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num = 1
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instance_type = {'memory_mb': 1024}
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request_spec = {'instance_type': instance_type}
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hosts = self.sched.filter_hosts('compute', request_spec, None)
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expected = []
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for idx, (hostname, caps) in enumerate(hosts):
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# Costs are normalized so over 10 hosts, each host with increasing
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# free ram will cost 1/N more. Since the lowest cost host has some
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# free ram, we add in the 1/N for the base_cost
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weight = 0.1 + (0.1 * idx)
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weight_dict = dict(weight=weight, hostname=hostname)
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expected.append(weight_dict)
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self.assertWeights(expected, num, request_spec, hosts)
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