diff --git a/nova/scheduler/distributed_scheduler.py b/nova/scheduler/distributed_scheduler.py
index db1e1ed417d3..224b194018c7 100644
--- a/nova/scheduler/distributed_scheduler.py
+++ b/nova/scheduler/distributed_scheduler.py
@@ -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
diff --git a/nova/scheduler/filters/abstract_filter.py b/nova/scheduler/filters/abstract_filter.py
index 5784f8791b3a..45fcd3ea1515 100644
--- a/nova/scheduler/filters/abstract_filter.py
+++ b/nova/scheduler/filters/abstract_filter.py
@@ -23,7 +23,7 @@ class AbstractHostFilter(object):
         """Convert instance_type into a filter for most common use-case."""
         raise NotImplementedError()
 
-    def filter_hosts(self, host_list, query):
+    def filter_hosts(self, host_list, query, options):
         """Return a list of hosts that fulfill the filter."""
         raise NotImplementedError()
 
diff --git a/nova/scheduler/filters/all_hosts_filter.py b/nova/scheduler/filters/all_hosts_filter.py
index 7e6d2573b8ce..6ca4c281e2f9 100644
--- a/nova/scheduler/filters/all_hosts_filter.py
+++ b/nova/scheduler/filters/all_hosts_filter.py
@@ -26,6 +26,6 @@ class AllHostsFilter(abstract_filter.AbstractHostFilter):
         """
         return instance_type
 
-    def filter_hosts(self, host_list, query):
+    def filter_hosts(self, host_list, query, options):
         """Return the entire list of supplied hosts."""
         return list(host_list)
diff --git a/nova/scheduler/filters/instance_type_filter.py b/nova/scheduler/filters/instance_type_filter.py
index 2104924d7346..7e05cb9e7e89 100644
--- a/nova/scheduler/filters/instance_type_filter.py
+++ b/nova/scheduler/filters/instance_type_filter.py
@@ -51,7 +51,7 @@ class InstanceTypeFilter(abstract_filter.AbstractHostFilter):
         free_ram_mb = host_info.free_ram_mb
         return free_ram_mb >= requested_ram
 
-    def filter_hosts(self, host_list, query):
+    def filter_hosts(self, host_list, query, options):
         """Return a list of hosts that can create instance_type."""
         instance_type = query
         selected_hosts = []
diff --git a/nova/scheduler/filters/json_filter.py b/nova/scheduler/filters/json_filter.py
index 5eea38bc791f..692a330bb927 100644
--- a/nova/scheduler/filters/json_filter.py
+++ b/nova/scheduler/filters/json_filter.py
@@ -134,7 +134,7 @@ class JsonFilter(abstract_filter.AbstractHostFilter):
         result = method(self, cooked_args)
         return result
 
-    def filter_hosts(self, host_list, query):
+    def filter_hosts(self, host_list, query, options):
         """Return a list of hosts that can fulfill the requirements
         specified in the query.
         """
diff --git a/nova/scheduler/least_cost.py b/nova/scheduler/least_cost.py
index 83dc087abd16..7e12ca390865 100644
--- a/nova/scheduler/least_cost.py
+++ b/nova/scheduler/least_cost.py
@@ -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)
diff --git a/nova/scheduler/scheduler_options.py b/nova/scheduler/scheduler_options.py
new file mode 100644
index 000000000000..61966dc50b6f
--- /dev/null
+++ b/nova/scheduler/scheduler_options.py
@@ -0,0 +1,98 @@
+# 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.
+
+"""
+SchedulerOptions monitors a local .json file for changes and loads
+it if needed. This file is converted to a data structure and passed
+into the filtering and weighing functions which can use it for
+dynamic configuration.
+"""
+
+import datetime
+import json
+import os
+
+from nova import flags
+from nova import log as logging
+
+
+FLAGS = flags.FLAGS
+flags.DEFINE_string('scheduler_json_config_location',
+        '',
+        'Absolute path to scheduler configuration JSON file.')
+
+LOG = logging.getLogger('nova.scheduler.scheduler_options')
+
+
+class SchedulerOptions(object):
+    """
+    SchedulerOptions monitors a local .json file for changes and loads it
+    if needed. This file is converted to a data structure and passed into
+    the filtering and weighing functions which can use it for dynamic
+    configuration.
+    """
+
+    def __init__(self):
+        super(SchedulerOptions, self).__init__()
+        self.data = {}
+        self.last_modified = None
+        self.last_checked = None
+
+    def _get_file_handle(self, filename):
+        """Get file handle. Broken out for testing."""
+        return open(filename)
+
+    def _get_file_timestamp(self, filename):
+        """Get the last modified datetime. Broken out for testing."""
+        try:
+            return os.path.getmtime(filename)
+        except os.error, e:
+            LOG.exception(_("Could not stat scheduler options file "
+                            "%(filename)s: '%(e)s'", locals()))
+            raise
+
+    def _load_file(self, handle):
+        """Decode the JSON file. Broken out for testing."""
+        try:
+            return json.load(handle)
+        except ValueError, e:
+            LOG.exception(_("Could not decode scheduler options: "
+                            "'%(e)s'") % locals())
+            return {}
+
+    def _get_time_now(self):
+        """Get current UTC. Broken out for testing."""
+        return datetime.datetime.utcnow()
+
+    def get_configuration(self, filename=None):
+        """Check the json file for changes and load it if needed."""
+        if not filename:
+            filename = FLAGS.scheduler_json_config_location
+        if not filename:
+            return self.data
+        if self.last_checked:
+            now = self._get_time_now()
+            if now - self.last_checked < datetime.timedelta(minutes=5):
+                return self.data
+
+        last_modified = self._get_file_timestamp(filename)
+        if not last_modified or not self.last_modified or \
+                                        last_modified > self.last_modified:
+            self.data = self._load_file(self._get_file_handle(filename))
+            self.last_modified = last_modified
+        if not self.data:
+            self.data = {}
+
+        return self.data
diff --git a/nova/tests/scheduler/test_distributed_scheduler.py b/nova/tests/scheduler/test_distributed_scheduler.py
index a66fae343caa..657232f7bf0d 100644
--- a/nova/tests/scheduler/test_distributed_scheduler.py
+++ b/nova/tests/scheduler/test_distributed_scheduler.py
@@ -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))
diff --git a/nova/tests/scheduler/test_host_filter.py b/nova/tests/scheduler/test_host_filter.py
index b5b5aadefaeb..62131a625344 100644
--- a/nova/tests/scheduler/test_host_filter.py
+++ b/nova/tests/scheduler/test_host_filter.py
@@ -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']]), {}))
diff --git a/nova/tests/scheduler/test_least_cost.py b/nova/tests/scheduler/test_least_cost.py
index a45e951817e4..4a3af2eac8ac 100644
--- a/nova/tests/scheduler/test_least_cost.py
+++ b/nova/tests/scheduler/test_least_cost.py
@@ -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))
diff --git a/nova/tests/scheduler/test_scheduler_options.py b/nova/tests/scheduler/test_scheduler_options.py
new file mode 100644
index 000000000000..d99452b59961
--- /dev/null
+++ b/nova/tests/scheduler/test_scheduler_options.py
@@ -0,0 +1,138 @@
+# Copyright 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.
+"""
+Tests For PickledScheduler.
+"""
+
+import datetime
+import json
+import StringIO
+
+from nova.scheduler import scheduler_options
+from nova import test
+
+
+class FakeSchedulerOptions(scheduler_options.SchedulerOptions):
+    def __init__(self, last_checked, now, file_old, file_now, data, filedata):
+        super(FakeSchedulerOptions, self).__init__()
+        # Change internals ...
+        self.last_modified = file_old
+        self.last_checked = last_checked
+        self.data = data
+
+        # For overrides ...
+        self._time_now = now
+        self._file_now = file_now
+        self._file_data = filedata
+
+        self.file_was_loaded = False
+
+    def _get_file_timestamp(self, filename):
+        return self._file_now
+
+    def _get_file_handle(self, filename):
+        self.file_was_loaded = True
+        return StringIO.StringIO(self._file_data)
+
+    def _get_time_now(self):
+        return self._time_now
+
+
+class SchedulerOptionsTestCase(test.TestCase):
+    def test_get_configuration_first_time_no_flag(self):
+        last_checked = None
+        now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_old = None
+        file_now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+
+        data = dict(a=1, b=2, c=3)
+        jdata = json.dumps(data)
+
+        fake = FakeSchedulerOptions(last_checked, now, file_old, file_now,
+                                                                  {}, jdata)
+        self.assertEquals({}, fake.get_configuration())
+        self.assertFalse(fake.file_was_loaded)
+
+    def test_get_configuration_first_time_empty_file(self):
+        last_checked = None
+        now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_old = None
+        file_now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+
+        data = dict(a=1, b=2, c=3)
+        jdata = ""
+
+        fake = FakeSchedulerOptions(last_checked, now, file_old, file_now,
+                                                                  {}, jdata)
+        self.assertEquals({}, fake.get_configuration('foo.json'))
+        self.assertTrue(fake.file_was_loaded)
+
+    def test_get_configuration_first_time_happy_day(self):
+        last_checked = None
+        now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_old = None
+        file_now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+
+        data = dict(a=1, b=2, c=3)
+        jdata = json.dumps(data)
+
+        fake = FakeSchedulerOptions(last_checked, now, file_old, file_now,
+                                                                  {}, jdata)
+        self.assertEquals(data, fake.get_configuration('foo.json'))
+        self.assertTrue(fake.file_was_loaded)
+
+    def test_get_configuration_second_time_no_change(self):
+        last_checked = datetime.datetime(2011, 1, 1, 1, 1, 1)
+        now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_old = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+
+        data = dict(a=1, b=2, c=3)
+        jdata = json.dumps(data)
+
+        fake = FakeSchedulerOptions(last_checked, now, file_old, file_now,
+                                                                 data, jdata)
+        self.assertEquals(data, fake.get_configuration('foo.json'))
+        self.assertFalse(fake.file_was_loaded)
+
+    def test_get_configuration_second_time_too_fast(self):
+        last_checked = datetime.datetime(2011, 1, 1, 1, 1, 1)
+        now = datetime.datetime(2011, 1, 1, 1, 1, 2)
+        file_old = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_now = datetime.datetime(2013, 1, 1, 1, 1, 1)
+
+        old_data = dict(a=1, b=2, c=3)
+        data = dict(a=11, b=12, c=13)
+        jdata = json.dumps(data)
+
+        fake = FakeSchedulerOptions(last_checked, now, file_old, file_now,
+                                                            old_data, jdata)
+        self.assertEquals(old_data, fake.get_configuration('foo.json'))
+        self.assertFalse(fake.file_was_loaded)
+
+    def test_get_configuration_second_time_change(self):
+        last_checked = datetime.datetime(2011, 1, 1, 1, 1, 1)
+        now = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_old = datetime.datetime(2012, 1, 1, 1, 1, 1)
+        file_now = datetime.datetime(2013, 1, 1, 1, 1, 1)
+
+        old_data = dict(a=1, b=2, c=3)
+        data = dict(a=11, b=12, c=13)
+        jdata = json.dumps(data)
+
+        fake = FakeSchedulerOptions(last_checked, now, file_old, file_now,
+                                                            old_data, jdata)
+        self.assertEquals(data, fake.get_configuration('foo.json'))
+        self.assertTrue(fake.file_was_loaded)