openstack/nova
Code Issues Proposed changes

Merge "Added a new scheduler metrics weight plugin"

Browse Source
This commit is contained in:
Jenkins 2013-12-07 20:05:10 +00:00 committed by Gerrit Code Review
commit d83c9a6aa0
6 changed files with 1016 additions and 704 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
doc/source/devref/filter_scheduler.rst
View File

@ -266,9 +266,24 @@ Weights
Filter Scheduler uses so-called **weights** during its work.
The Filter Scheduler weights hosts based on the config option
``scheduler_weight_classes``, this defaults to
``nova.scheduler.weights.all_weighers``, which selects the only weigher available
-- the RamWeigher. Hosts are then weighted and sorted with the largest weight winning.
`scheduler_weight_classes`, this defaults to
`nova.scheduler.weights.all_weighers`, which selects all the available weighers
in the package nova.scheduler.weights. Hosts are then weighted and sorted with
the largest weight winning. For each host, the final weight is calculated by
summing up all weigher's weight value multiplying its own weight_mutiplier:
::
final_weight = 0
for each weigher:
final_weight += weigher's weight_mutiplier * weigher's calculated weight value
The weigher's weight_mutiplier can be set in the configuration file, e.g.
::
[metrics]
weight_multiplier=1.0
Filter Scheduler finds local list of acceptable hosts by repeated filtering and
weighing. Each time it chooses a host, it virtually consumes resources on it,

1406
etc/nova/nova.conf.sample
View File

File diff suppressed because it is too large Load Diff

5
nova/exception.py
View File

@ -960,6 +960,11 @@ class FlavorExtraSpecsNotFound(NotFound):
"key %(extra_specs_key)s.")
class ComputeHostMetricNotFound(NotFound):
msg_fmt = _("Metric %(name)s could not be found on the compute "
"host node %(host)s.%(node)s.")
class FileNotFound(NotFound):
msg_fmt = _("File %(file_path)s could not be found.")

94
nova/scheduler/weights/metrics.py Normal file
View File

@ -0,0 +1,94 @@
# 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.
"""
Metrics Weigher. Weigh hosts by their metrics.
This weigher can compute the weight based on the compute node host's various
metrics. The to-be weighed metrics and their weighing ratio are specified
in the configuration file as the followings:
metrics_weight_setting = name1=1.0, name2=-1.0
The final weight would be name1.value * 1.0 + name2.value * -1.0.
"""
from oslo.config import cfg
from nova import exception
from nova.openstack.common.gettextutils import _
from nova.openstack.common import log as logging
from nova.scheduler import weights
metrics_weight_opts = [
cfg.FloatOpt('weight_multiplier',
default=1.0,
help='Multiplier used for weighing metrics.'),
cfg.ListOpt('weight_setting',
default=[],
help='How the metrics are going to be weighed. This '
'should be in the form of "<name1>=<ratio1>, '
'<name2>=<ratio2>, ...", where <nameX> is one '
'of the metric to be weighed, and <ratioX> is '
'the corresponding ratio. So for "name1=1.0, '
'name2=-1.0" The final weight would be '
'name1.value * 1.0 + name2.value * -1.0.'),
]
CONF = cfg.CONF
CONF.register_opts(metrics_weight_opts, group='metrics')
LOG = logging.getLogger(__name__)
class MetricsWeigher(weights.BaseHostWeigher):
def __init__(self):
self._parse_setting()
def _parse_setting(self):
self.setting = []
bad = []
for item in CONF.metrics.weight_setting:
try:
(name, ratio) = item.split('=')
ratio = float(ratio)
except ValueError:
name = None
ratio = None
if name and ratio is not None:
self.setting.append((name, ratio))
else:
bad.append(item)
if bad:
LOG.error(_("Ignoring the invalid elements of"
" metrics_weight_setting: %s"),
",".join(bad))
def _weight_multiplier(self):
"""Override the weight multiplier."""
return CONF.metrics.weight_multiplier
def _weigh_object(self, host_state, weight_properties):
value = 0.0
for (name, ratio) in self.setting:
try:
value += host_state.metrics[name].value * ratio
except KeyError:
raise exception.ComputeHostMetricNotFound(
host=host_state.host,
node=host_state.nodename,
name=name)
return value

72
nova/tests/scheduler/fakes.py
View File

@ -20,6 +20,7 @@ import mox
from nova.compute import vm_states
from nova import db
from nova.openstack.common import jsonutils
from nova.scheduler import filter_scheduler
from nova.scheduler import host_manager
@ -53,6 +54,77 @@ COMPUTE_NODES = [
dict(id=5, local_gb=1024, memory_mb=1024, vcpus=1, service=None),
]
COMPUTE_NODES_METRICS = [
dict(id=1, local_gb=1024, memory_mb=1024, vcpus=1,
disk_available_least=512, free_ram_mb=512, vcpus_used=1,
free_disk_mb=512, local_gb_used=0, updated_at=None,
service=dict(host='host1', disabled=False),
hypervisor_hostname='node1', host_ip='127.0.0.1',
hypervisor_version=0,
metrics=jsonutils.dumps([{'name': 'foo',
'value': 512,
'timestamp': None,
'source': 'host1'
},
{'name': 'bar',
'value': 1.0,
'timestamp': None,
'source': 'host1'
},
])),
dict(id=2, local_gb=2048, memory_mb=2048, vcpus=2,
disk_available_least=1024, free_ram_mb=1024, vcpus_used=2,
free_disk_mb=1024, local_gb_used=0, updated_at=None,
service=dict(host='host2', disabled=True),
hypervisor_hostname='node2', host_ip='127.0.0.1',
hypervisor_version=0,
metrics=jsonutils.dumps([{'name': 'foo',
'value': 1024,
'timestamp': None,
'source': 'host2'
},
{'name': 'bar',
'value': 2.0,
'timestamp': None,
'source': 'host2'
},
])),
dict(id=3, local_gb=4096, memory_mb=4096, vcpus=4,
disk_available_least=3072, free_ram_mb=3072, vcpus_used=1,
free_disk_mb=3072, local_gb_used=0, updated_at=None,
service=dict(host='host3', disabled=False),
hypervisor_hostname='node3', host_ip='127.0.0.1',
hypervisor_version=0,
metrics=jsonutils.dumps([{'name': 'foo',
'value': 3072,
'timestamp': None,
'source': 'host3'
},
{'name': 'bar',
'value': 1.0,
'timestamp': None,
'source': 'host3'
},
])),
dict(id=4, local_gb=8192, memory_mb=8192, vcpus=8,
disk_available_least=8192, free_ram_mb=8192, vcpus_used=0,
free_disk_mb=8192, local_gb_used=0, updated_at=None,
service=dict(host='host4', disabled=False),
hypervisor_hostname='node4', host_ip='127.0.0.1',
hypervisor_version=0,
metrics=jsonutils.dumps([{'name': 'foo',
'value': 8192,
'timestamp': None,
'source': 'host4'
},
{'name': 'bar',
'value': 0,
'timestamp': None,
'source': 'host4'
},
])),
]
INSTANCES = [
dict(root_gb=512, ephemeral_gb=0, memory_mb=512, vcpus=1,
host='host1', node='node1'),

122
nova/tests/scheduler/test_weights.py
View File

@ -17,6 +17,8 @@ Tests For Scheduler weights.
"""
from nova import context
from nova import exception
from nova.openstack.common.fixture import mockpatch
from nova.scheduler import weights
from nova import test
from nova.tests import matchers
@ -34,13 +36,17 @@ class TestWeighedHost(test.NoDBTestCase):
def test_all_weighers(self):
classes = weights.all_weighers()
class_names = [cls.__name__ for cls in classes]
self.assertEqual(len(classes), 1)
self.assertEqual(len(classes), 2)
self.assertIn('RAMWeigher', class_names)
self.assertIn('MetricsWeigher', class_names)
class RamWeigherTestCase(test.NoDBTestCase):
def setUp(self):
super(RamWeigherTestCase, self).setUp()
self.useFixture(mockpatch.Patch(
'nova.db.compute_node_get_all',
return_value=fakes.COMPUTE_NODES))
self.host_manager = fakes.FakeHostManager()
self.weight_handler = weights.HostWeightHandler()
self.weight_classes = self.weight_handler.get_matching_classes(
@ -54,12 +60,7 @@ class RamWeigherTestCase(test.NoDBTestCase):
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
return self.host_manager.get_all_host_states(ctxt)
def test_default_of_spreading_first(self):
hostinfo_list = self._get_all_hosts()
@ -101,3 +102,110 @@ class RamWeigherTestCase(test.NoDBTestCase):
weighed_host = self._get_weighed_host(hostinfo_list)
self.assertEqual(weighed_host.weight, 8192 * 2)
self.assertEqual(weighed_host.obj.host, 'host4')
class MetricsWeigherTestCase(test.NoDBTestCase):
def setUp(self):
super(MetricsWeigherTestCase, self).setUp()
self.useFixture(mockpatch.Patch(
'nova.db.compute_node_get_all',
return_value=fakes.COMPUTE_NODES_METRICS))
self.host_manager = fakes.FakeHostManager()
self.weight_handler = weights.HostWeightHandler()
self.weight_classes = self.weight_handler.get_matching_classes(
['nova.scheduler.weights.metrics.MetricsWeigher'])
def _get_weighed_host(self, hosts, setting, weight_properties=None):
if not weight_properties:
weight_properties = {}
self.flags(weight_setting=setting, group='metrics')
return self.weight_handler.get_weighed_objects(self.weight_classes,
hosts, weight_properties)[0]
def _get_all_hosts(self):
ctxt = context.get_admin_context()
return self.host_manager.get_all_host_states(ctxt)
def _do_test(self, settings, expected_weight, expected_host):
hostinfo_list = self._get_all_hosts()
weighed_host = self._get_weighed_host(hostinfo_list, settings)
self.assertEqual(weighed_host.weight, expected_weight)
self.assertEqual(weighed_host.obj.host, expected_host)
def test_single_resource(self):
# host1: foo=512
# host2: foo=1024
# host3: foo=3072
# host4: foo=8192
# so, host4 should win:
setting = ['foo=1']
self._do_test(setting, 8192, 'host4')
def test_multiple_resource(self):
# host1: foo=512, bar=1
# host2: foo=1024, bar=2
# host3: foo=3072, bar=1
# host4: foo=8192, bar=0
# so, host2 should win:
setting = ['foo=0.0001', 'bar=1']
self._do_test(setting, 2.1024, 'host2')
def test_single_resourcenegtive_ratio(self):
# host1: foo=512
# host2: foo=1024
# host3: foo=3072
# host4: foo=8192
# so, host1 should win:
setting = ['foo=-1']
self._do_test(setting, -512, 'host1')
def test_multiple_resource_missing_ratio(self):
# host1: foo=512, bar=1
# host2: foo=1024, bar=2
# host3: foo=3072, bar=1
# host4: foo=8192, bar=0
# so, host4 should win:
setting = ['foo=0.0001', 'bar']
self._do_test(setting, 0.8192, 'host4')
def test_multiple_resource_wrong_ratio(self):
# host1: foo=512, bar=1
# host2: foo=1024, bar=2
# host3: foo=3072, bar=1
# host4: foo=8192, bar=0
# so, host4 should win:
setting = ['foo=0.0001', 'bar = 2.0t']
self._do_test(setting, 0.8192, 'host4')
def _check_parsing_result(self, weigher, setting, results):
self.flags(weight_setting=setting, group='metrics')
weigher._parse_setting()
self.assertTrue(len(results) == len(weigher.setting))
for item in results:
self.assertTrue(item in weigher.setting)
def test_parse_setting(self):
weigher = self.weight_classes[0]()
self._check_parsing_result(weigher,
['foo=1'],
[('foo', 1.0)])
self._check_parsing_result(weigher,
['foo=1', 'bar=-2.1'],
[('foo', 1.0), ('bar', -2.1)])
self._check_parsing_result(weigher,
['foo=a1', 'bar=-2.1'],
[('bar', -2.1)])
self._check_parsing_result(weigher,
['foo', 'bar=-2.1'],
[('bar', -2.1)])
self._check_parsing_result(weigher,
['=5', 'bar=-2.1'],
[('bar', -2.1)])
def test_metric_not_found(self):
setting = ['foo=1', 'zot=2']
self.assertRaises(exception.ComputeHostMetricNotFound,
self._do_test,
setting,
8192,
'host4')