Merge "Add auto-reloading JSON config file support to scheduler."

This commit is contained in:
Jenkins
2011-11-08 14:40:32 +00:00
committed by Gerrit Code Review
5 changed files with 110 additions and 148 deletions

View File

@@ -25,21 +25,21 @@ import types
import M2Crypto
from nova.compute import api as compute_api
from novaclient import v1_1 as novaclient
from novaclient import exceptions as novaclient_exceptions
from nova import crypto
from nova import db
from nova import exception
from nova import flags
from nova import log as logging
from nova import rpc
from nova.compute import api as compute_api
from nova.scheduler import api
from nova.scheduler import driver
from nova.scheduler import filters
from nova.scheduler import least_cost
from nova.scheduler import scheduler_options
from nova import utils
FLAGS = flags.FLAGS
@@ -59,6 +59,10 @@ class DistributedScheduler(driver.Scheduler):
"""Scheduler that can work across any nova deployment, from simple
deployments to multiple nested zones.
"""
def __init__(self, *args, **kwargs):
super(DistributedScheduler, self).__init__(*args, **kwargs)
self.cost_function_cache = {}
self.options = scheduler_options.SchedulerOptions()
def schedule(self, context, topic, method, *args, **kwargs):
"""The schedule() contract requires we return the one
@@ -243,6 +247,10 @@ class DistributedScheduler(driver.Scheduler):
"""Broken out for testing."""
return db.zone_get_all(context)
def _get_configuration_options(self):
"""Fetch options dictionary. Broken out for testing."""
return self.options.get_configuration()
def _schedule(self, elevated, topic, request_spec, *args, **kwargs):
"""Returns a list of hosts that meet the required specs,
ordered by their fitness.
@@ -257,9 +265,13 @@ class DistributedScheduler(driver.Scheduler):
"provisioning.")
raise NotImplementedError(msg)
cost_functions = self.get_cost_functions()
ram_requirement_mb = instance_type['memory_mb']
disk_requirement_bg = instance_type['local_gb']
options = self._get_configuration_options()
# Find our local list of acceptable hosts by repeatedly
# filtering and weighing our options. Each time we choose a
# host, we virtually consume resources on it so subsequent
@@ -274,7 +286,7 @@ class DistributedScheduler(driver.Scheduler):
for num in xrange(num_instances):
# Filter local hosts based on requirements ...
filtered_hosts = self._filter_hosts(topic, request_spec,
unfiltered_hosts)
unfiltered_hosts, options)
if not filtered_hosts:
# Can't get any more locally.
@@ -284,8 +296,8 @@ class DistributedScheduler(driver.Scheduler):
# weighted_host = WeightedHost() ... the best
# host for the job.
weighted_host = least_cost.weigh_hosts(request_spec,
filtered_hosts)
weighted_host = least_cost.weighted_sum(cost_functions,
filtered_hosts, options)
LOG.debug(_("Weighted %(weighted_host)s") % locals())
selected_hosts.append(weighted_host)
@@ -343,7 +355,7 @@ class DistributedScheduler(driver.Scheduler):
raise exception.SchedulerHostFilterNotFound(filter_name=msg)
return good_filters
def _filter_hosts(self, topic, request_spec, hosts=None):
def _filter_hosts(self, topic, request_spec, hosts, options):
"""Filter the full host list. hosts = [(host, HostInfo()), ...].
This method returns a subset of hosts, in the same format."""
selected_filters = self._choose_host_filters()
@@ -358,6 +370,48 @@ class DistributedScheduler(driver.Scheduler):
for selected_filter in selected_filters:
query = selected_filter.instance_type_to_filter(instance_type)
hosts = selected_filter.filter_hosts(hosts, query)
hosts = selected_filter.filter_hosts(hosts, query, options)
return hosts
def get_cost_functions(self, topic=None):
"""Returns a list of tuples containing weights and cost functions to
use for weighing hosts
"""
if topic is None:
# Schedulers only support compute right now.
topic = "compute"
if topic in self.cost_function_cache:
return self.cost_function_cache[topic]
cost_fns = []
for cost_fn_str in FLAGS.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('%s_' % topic) 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 = utils.import_class(cost_fn_str)
except exception.ClassNotFound:
raise exception.SchedulerCostFunctionNotFound(
cost_fn_str=cost_fn_str)
try:
flag_name = "%s_weight" % cost_fn.__name__
weight = getattr(FLAGS, flag_name)
except AttributeError:
raise exception.SchedulerWeightFlagNotFound(
flag_name=flag_name)
cost_fns.append((weight, cost_fn))
self.cost_function_cache[topic] = cost_fns
return cost_fns

View File

@@ -23,11 +23,8 @@ is then selected for provisioning.
"""
import collections
from nova import flags
from nova import log as logging
from nova import utils
from nova import exception
LOG = logging.getLogger('nova.scheduler.least_cost')
@@ -46,9 +43,6 @@ flags.DEFINE_float('compute_fill_first_cost_fn_weight', 1.0,
'How much weight to give the fill-first cost function')
COST_FUNCTION_CACHE = {}
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
@@ -74,36 +68,18 @@ class WeightedHost(object):
return x
def noop_cost_fn(host_info):
def noop_cost_fn(host_info, options=None):
"""Return a pre-weight cost of 1 for each host"""
return 1
def compute_fill_first_cost_fn(host_info):
def compute_fill_first_cost_fn(host_info, options=None):
"""More free ram = higher weight. So servers will less free
ram will be preferred."""
return host_info.free_ram_mb
def normalize_grid(grid):
"""Normalize a grid of numbers by row."""
if not grid:
return [[]]
normalized = []
for row in grid:
if not row:
normalized.append([])
continue
mx = float(max(row))
if abs(mx) < 0.001:
normalized = [0.0] * len(row)
continue
normalized.append([float(col) / mx for col in row])
return normalized
def weighted_sum(host_list, weighted_fns):
def weighted_sum(weighted_fns, host_list, options):
"""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.
@@ -111,6 +87,7 @@ def weighted_sum(host_list, weighted_fns):
host_list - [(host, HostInfo()), ...]
weighted_fns - list of weights and functions like:
[(weight, objective-functions), ...]
options is an arbitrary dict of values.
Returns a single WeightedHost object which represents the best
candidate.
@@ -120,8 +97,8 @@ def weighted_sum(host_list, weighted_fns):
# One row per host. One column per function.
scores = []
for weight, fn in weighted_fns:
scores.append([fn(host_info) for hostname, host_info in host_list])
scores = normalize_grid(scores)
scores.append([fn(host_info, options) for hostname, host_info
in host_list])
# Adjust the weights in the grid by the functions weight adjustment
# and sum them up to get a final list of weights.
@@ -143,54 +120,3 @@ def weighted_sum(host_list, weighted_fns):
final_scores = sorted(final_scores)
weight, (host, hostinfo) = final_scores[0] # Lowest score is the winner!
return WeightedHost(weight, host=host, hostinfo=hostinfo)
def get_cost_fns(topic=None):
"""Returns a list of tuples containing weights and cost functions to
use for weighing hosts
"""
global COST_FUNCTION_CACHE
cost_function_cache = COST_FUNCTION_CACHE
if topic is None:
# Schedulers only support compute right now.
topic = "compute"
if topic in cost_function_cache:
return cost_function_cache[topic]
cost_fns = []
for cost_fn_str in FLAGS.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('%s_' % topic) or
short_name.startswith('noop')):
continue
try:
# NOTE(sirp): import_class is somewhat misnamed since it can
# any callable from a module
cost_fn = utils.import_class(cost_fn_str)
except exception.ClassNotFound:
raise exception.SchedulerCostFunctionNotFound(
cost_fn_str=cost_fn_str)
try:
flag_name = "%s_weight" % cost_fn.__name__
weight = getattr(FLAGS, flag_name)
except AttributeError:
raise exception.SchedulerWeightFlagNotFound(
flag_name=flag_name)
cost_fns.append((weight, cost_fn))
cost_function_cache[topic] = cost_fns
return cost_fns
def weigh_hosts(request_spec, host_list):
"""Returns the best host as a WeightedHost."""
cost_fns = get_cost_fns()
return weighted_sum(host_list, cost_fns)

View File

@@ -212,10 +212,11 @@ class DistributedSchedulerTestCase(test.TestCase):
self.next_weight = 1.0
def _fake_filter_hosts(topic, request_info, unfiltered_hosts):
def _fake_filter_hosts(topic, request_info, unfiltered_hosts,
options):
return unfiltered_hosts
def _fake_weigh_hosts(request_info, hosts):
def _fake_weighted_sum(functions, hosts, options):
self.next_weight += 2.0
host, hostinfo = hosts[0]
return least_cost.WeightedHost(self.next_weight, host=host,
@@ -225,7 +226,7 @@ class DistributedSchedulerTestCase(test.TestCase):
fake_context = context.RequestContext('user', 'project')
sched.zone_manager = ds_fakes.FakeZoneManager()
self.stubs.Set(sched, '_filter_hosts', _fake_filter_hosts)
self.stubs.Set(least_cost, 'weigh_hosts', _fake_weigh_hosts)
self.stubs.Set(least_cost, 'weighted_sum', _fake_weighted_sum)
self.stubs.Set(nova.db, 'zone_get_all', fake_zone_get_all)
self.stubs.Set(sched, '_call_zone_method', fake_call_zone_method)
@@ -260,3 +261,12 @@ class DistributedSchedulerTestCase(test.TestCase):
self.assertTrue(isinstance(weighted_host, least_cost.WeightedHost))
self.assertEqual(weighted_host.to_dict(), dict(weight=1, host='x',
blob='y', zone='z'))
def test_get_cost_functions(self):
fixture = ds_fakes.FakeDistributedScheduler()
fns = fixture.get_cost_functions()
self.assertEquals(len(fns), 1)
weight, fn = fns[0]
self.assertEquals(weight, 1.0)
hostinfo = zone_manager.HostInfo('host', free_ram_mb=1000)
self.assertEquals(1000, fn(hostinfo))

View File

@@ -122,7 +122,7 @@ class HostFilterTestCase(test.TestCase):
hf = hfs[0]
all_hosts = self._get_all_hosts()
cooked = hf.instance_type_to_filter(self.instance_type)
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(4, len(hosts))
for host, capabilities in hosts:
self.assertTrue(host.startswith('host'))
@@ -132,7 +132,7 @@ class HostFilterTestCase(test.TestCase):
# filter all hosts that can support 30 ram and 300 disk
cooked = hf.instance_type_to_filter(self.instance_type)
all_hosts = self._get_all_hosts()
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(3, len(hosts))
just_hosts = [host for host, hostinfo in hosts]
just_hosts.sort()
@@ -147,7 +147,7 @@ class HostFilterTestCase(test.TestCase):
# reserving 2048 ram
cooked = hf.instance_type_to_filter(self.instance_type)
all_hosts = self._get_all_hosts()
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(2, len(hosts))
just_hosts = [host for host, hostinfo in hosts]
just_hosts.sort()
@@ -159,7 +159,7 @@ class HostFilterTestCase(test.TestCase):
# filter all hosts that can support 30 ram and 300 disk
cooked = hf.instance_type_to_filter(self.gpu_instance_type)
all_hosts = self._get_all_hosts()
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(1, len(hosts))
just_hosts = [host for host, caps in hosts]
self.assertEquals('host4', just_hosts[0])
@@ -169,7 +169,7 @@ class HostFilterTestCase(test.TestCase):
# filter all hosts that can support 30 ram and 300 disk
cooked = hf.instance_type_to_filter(self.instance_type)
all_hosts = self._get_all_hosts()
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(2, len(hosts))
just_hosts = [host for host, caps in hosts]
just_hosts.sort()
@@ -189,7 +189,7 @@ class HostFilterTestCase(test.TestCase):
]
]
cooked = json.dumps(raw)
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(3, len(hosts))
just_hosts = [host for host, caps in hosts]
@@ -201,7 +201,7 @@ class HostFilterTestCase(test.TestCase):
['=', '$compute.host_memory_free', 30],
]
cooked = json.dumps(raw)
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(3, len(hosts))
just_hosts = [host for host, caps in hosts]
@@ -211,7 +211,7 @@ class HostFilterTestCase(test.TestCase):
raw = ['in', '$compute.host_memory_free', 20, 40, 60, 80, 100]
cooked = json.dumps(raw)
hosts = hf.filter_hosts(all_hosts, cooked)
hosts = hf.filter_hosts(all_hosts, cooked, {})
self.assertEquals(2, len(hosts))
just_hosts = [host for host, caps in hosts]
just_hosts.sort()
@@ -222,32 +222,32 @@ class HostFilterTestCase(test.TestCase):
raw = ['unknown command', ]
cooked = json.dumps(raw)
try:
hf.filter_hosts(all_hosts, cooked)
hf.filter_hosts(all_hosts, cooked, {})
self.fail("Should give KeyError")
except KeyError, e:
pass
self.assertTrue(hf.filter_hosts(all_hosts, json.dumps([])))
self.assertTrue(hf.filter_hosts(all_hosts, json.dumps({})))
self.assertTrue(hf.filter_hosts(all_hosts, json.dumps([]), {}))
self.assertTrue(hf.filter_hosts(all_hosts, json.dumps({}), {}))
self.assertTrue(hf.filter_hosts(all_hosts, json.dumps(
['not', True, False, True, False],
)))
), {}))
try:
hf.filter_hosts(all_hosts, json.dumps(
'not', True, False, True, False,
))
'not', True, False, True, False,), {})
self.fail("Should give KeyError")
except KeyError, e:
pass
self.assertFalse(hf.filter_hosts(all_hosts,
json.dumps(['=', '$foo', 100])))
json.dumps(['=', '$foo', 100]), {}))
self.assertFalse(hf.filter_hosts(all_hosts,
json.dumps(['=', '$.....', 100])))
json.dumps(['=', '$.....', 100]), {}))
self.assertFalse(hf.filter_hosts(all_hosts,
json.dumps(
['>', ['and', ['or', ['not', ['<', ['>=', ['<=', ['in', ]]]]]]]])))
['>', ['and', ['or', ['not', ['<', ['>=', ['<=', ['in', ]]]]]]]]),
{}))
self.assertFalse(hf.filter_hosts(all_hosts,
json.dumps(['=', {}, ['>', '$missing....foo']])))
json.dumps(['=', {}, ['>', '$missing....foo']]), {}))

View File

@@ -21,11 +21,11 @@ from nova import test
from nova.tests.scheduler import fake_zone_manager
def offset(hostinfo):
def offset(hostinfo, options):
return hostinfo.free_ram_mb + 10000
def scale(hostinfo):
def scale(hostinfo, options):
return hostinfo.free_ram_mb * 2
@@ -39,23 +39,6 @@ class LeastCostTestCase(test.TestCase):
def tearDown(self):
super(LeastCostTestCase, self).tearDown()
def test_normalize_grid(self):
raw = [
[1, 2, 3, 4, 5],
[10, 20, 30, 40, 50],
[100, 200, 300, 400, 500],
]
expected = [
[.2, .4, .6, .8, 1.0],
[.2, .4, .6, .8, 1.0],
[.2, .4, .6, .8, 1.0],
]
self.assertEquals(expected, least_cost.normalize_grid(raw))
self.assertEquals([[]], least_cost.normalize_grid([]))
self.assertEquals([[]], least_cost.normalize_grid([[]]))
def test_weighted_sum_happy_day(self):
fn_tuples = [(1.0, offset), (1.0, scale)]
hostinfo_list = self.zone_manager.get_all_host_data(None).items()
@@ -69,16 +52,14 @@ class LeastCostTestCase(test.TestCase):
# [10000, 11536, 13072, 18192]
# [0, 768, 1536, 4096]
# normalized =
# [ 0.55, 0.63, 0.72, 1.0]
# [ 0.0, 0.19, 0.38, 1.0]
# adjusted [ 1.0 * x + 1.0 * y] =
# [0.55, 0.82, 1.1, 2.0]
# [10000, 12304, 14608, 22288]
# so, host1 should win:
weighted_host = least_cost.weighted_sum(hostinfo_list, fn_tuples)
self.assertTrue(abs(weighted_host.weight - 0.55) < 0.01)
options = {}
weighted_host = least_cost.weighted_sum(fn_tuples, hostinfo_list,
options)
self.assertEqual(weighted_host.weight, 10000)
self.assertEqual(weighted_host.host, 'host1')
def test_weighted_sum_single_function(self):
@@ -93,18 +74,9 @@ class LeastCostTestCase(test.TestCase):
# [offset, ]=
# [10000, 11536, 13072, 18192]
# normalized =
# [ 0.55, 0.63, 0.72, 1.0]
# so, host1 should win:
weighted_host = least_cost.weighted_sum(hostinfo_list, fn_tuples)
self.assertTrue(abs(weighted_host.weight - 0.55) < 0.01)
options = {}
weighted_host = least_cost.weighted_sum(fn_tuples, hostinfo_list,
options)
self.assertEqual(weighted_host.weight, 10000)
self.assertEqual(weighted_host.host, 'host1')
def test_get_cost_functions(self):
fns = least_cost.get_cost_fns()
self.assertEquals(len(fns), 1)
weight, fn = fns[0]
self.assertEquals(weight, 1.0)
hostinfo = zone_manager.HostInfo('host', free_ram_mb=1000)
self.assertEquals(1000, fn(hostinfo))