Merge lp:~cbehrens/nova/dist-sched-enhancements into lp:~hudson-openstack/nova/trunk

[Chris Behrens]

compute_api.get_all should be able to recurse zones (bug 744217).
Also, allow to build more than one instance at once with zone_aware_scheduler types.
Other cleanups with regards to zone aware scheduler...

[Ed Leafe (ed-leafe)]

Lines 8-15: if min_count is specified, but no max_count, then at line 14, min_count will be some integer, and max_count will be None. Line 15 will then set min_count to None, too. Is that the desired behavior? Wouldn't the logic used in lines 94-95 make more sense?

Lines 45-51: as long as you're changing that line, can you fix the wonky indentation of the continued lines to use one of the standards for nova? Two levels (i.e., 8 spaces) is preferred, but you can also do the 'align with the item in the main line' approach. The current indentation uses something apparently random.

Lines 168-174: same as above.

Line 485: The log message sounds incorrect; instead of saying "ran out of hosts after weighing", it should probably say "no available hosts after filtering" or something like that.

review: Needs Fixing

[Chris Behrens (cbehrens)]

Oops, yeah. 8-15 doesn't make complete sense, does it? hehe. Will fix.

45-51, 168-174: Good call.

485: Yeah, that message is not quite right. I originally had that message in weigh_hosts in least_cost.py where it made sense at the time.

[Ed Leafe (ed-leafe)]

Changes look good.

review: Approve

[Rick Harris (rconradharris)]

Looks solid overall.

> 13 + if not min_count:
> 14 + min_count = 1
> 15 + else:
> 16 + min_count = int(min_count)

This looks like a double-negative: if NOT then do this; if NOT NOT then do that. Might be clearer as:

    if min_count:
        min_count = int(min_count)
    else:
        min_count = 1

or even:

    min_count = int(min_count) if min_count else 1

This is the kind of nit which is personal-preference so feel free to disregard
if you don't agree :)

> 50 + recurse_zones = query_str.get('recurse_zones')
> 51 + recurse_zones = recurse_zones and True or False

Won't this mean if you pass 'False' or '0' that recurse_zones is interpreted
as True. Is that expected behavior?

If we don't already have anything in utils yet, might be worth adding a
bool_from_str function. Something like:

    def bool_from_str(val):
        return val.lower() in ('true', '1')

    recurse_zones = utils.bool_from_str(query_str.get('recurse_zones'))

[Chris Behrens (cbehrens)]

Ah, the recurse_zones thing.. I mistakenly was thinking the variable was an int value. But you're right. It's a string. Probably worth adding that call in utils.

I'll fix up the min_count thing, also.. I tend to like using a positive expression when there's an 'else' case as well..

[Rick Harris (rconradharris)]

Looks good; thanks for adding the bool_from_str tests.

review: Approve

[Josh Kearney (jk0)]

LGTM!

review: Approve

=== modified file 'nova/api/openstack/create_instance_helper.py'
--- nova/api/openstack/create_instance_helper.py	2011-06-17 17:17:14 +0000
+++ nova/api/openstack/create_instance_helper.py	2011-06-29 22:27:29 +0000
@@ -114,6 +114,15 @@
         name = name.strip()
 
         reservation_id = body['server'].get('reservation_id')
+        min_count = body['server'].get('min_count')
+        max_count = body['server'].get('max_count')
+        # min_count and max_count are optional.  If they exist, they come
+        # in as strings.  We want to default 'min_count' to 1, and default
+        # 'max_count' to be 'min_count'.
+        min_count = int(min_count) if min_count else 1
+        max_count = int(max_count) if max_count else min_count
+        if min_count > max_count:
+            min_count = max_count
 
         try:
             inst_type = \
@@ -137,7 +146,9 @@
                                   injected_files=injected_files,
                                   admin_password=password,
                                   zone_blob=zone_blob,
-                                  reservation_id=reservation_id))
+                                  reservation_id=reservation_id,
+                                  min_count=min_count,
+                                  max_count=max_count))
         except quota.QuotaError as error:
             self._handle_quota_error(error)
         except exception.ImageNotFound as error:

=== modified file 'nova/api/openstack/servers.py'
--- nova/api/openstack/servers.py	2011-06-15 20:58:55 +0000
+++ nova/api/openstack/servers.py	2011-06-29 22:27:29 +0000
@@ -76,10 +76,17 @@
 
         builder - the response model builder
         """
-        reservation_id = req.str_GET.get('reservation_id')
+        query_str = req.str_GET
+        reservation_id = query_str.get('reservation_id')
+        project_id = query_str.get('project_id')
+        fixed_ip = query_str.get('fixed_ip')
+        recurse_zones = utils.bool_from_str(query_str.get('recurse_zones'))
         instance_list = self.compute_api.get_all(
-                                            req.environ['nova.context'],
-                                            reservation_id=reservation_id)
+                req.environ['nova.context'],
+                reservation_id=reservation_id,
+                project_id=project_id,
+                fixed_ip=fixed_ip,
+                recurse_zones=recurse_zones)
         limited_list = self._limit_items(instance_list, req)
         builder = self._get_view_builder(req)
         servers = [builder.build(inst, is_detail)['server']
@@ -111,14 +118,15 @@
         extra_values = None
         result = None
         try:
-            extra_values, result = self.helper.create_instance(
-                                    req, body, self.compute_api.create)
+            extra_values, instances = self.helper.create_instance(
+                    req, body, self.compute_api.create)
         except faults.Fault, f:
             return f
 
-        instances = result
-
-        (inst, ) = instances
+        # We can only return 1 instance via the API, if we happen to
+        # build more than one...  instances is a list, so we'll just
+        # use the first one..
+        inst = instances[0]
         for key in ['instance_type', 'image_ref']:
             inst[key] = extra_values[key]
 

=== modified file 'nova/compute/api.py'
--- nova/compute/api.py	2011-06-28 22:05:41 +0000
+++ nova/compute/api.py	2011-06-29 22:27:29 +0000
@@ -143,7 +143,7 @@
 
     def _check_create_parameters(self, context, instance_type,
                image_href, kernel_id=None, ramdisk_id=None,
-               min_count=1, max_count=1,
+               min_count=None, max_count=None,
                display_name='', display_description='',
                key_name=None, key_data=None, security_group='default',
                availability_zone=None, user_data=None, metadata={},
@@ -154,6 +154,10 @@
 
         if not instance_type:
             instance_type = instance_types.get_default_instance_type()
+        if not min_count:
+            min_count = 1
+        if not max_count:
+            max_count = min_count
 
         num_instances = quota.allowed_instances(context, max_count,
                                                 instance_type)
@@ -338,7 +342,7 @@
 
     def create_all_at_once(self, context, instance_type,
                image_href, kernel_id=None, ramdisk_id=None,
-               min_count=1, max_count=1,
+               min_count=None, max_count=None,
                display_name='', display_description='',
                key_name=None, key_data=None, security_group='default',
                availability_zone=None, user_data=None, metadata={},
@@ -368,7 +372,7 @@
 
     def create(self, context, instance_type,
                image_href, kernel_id=None, ramdisk_id=None,
-               min_count=1, max_count=1,
+               min_count=None, max_count=None,
                display_name='', display_description='',
                key_name=None, key_data=None, security_group='default',
                availability_zone=None, user_data=None, metadata={},
@@ -613,17 +617,53 @@
         """
         return self.get(context, instance_id)
 
-    def get_all_across_zones(self, context, reservation_id):
-        """Get all instances with this reservation_id, across
-        all available Zones (if any).
+    def get_all(self, context, project_id=None, reservation_id=None,
+                fixed_ip=None, recurse_zones=False):
+        """Get all instances filtered by one of the given parameters.
+
+        If there is no filter and the context is an admin, it will retreive
+        all instances in the system.
         """
-        context = context.elevated()
-        instances = self.db.instance_get_all_by_reservation(
+
+        if reservation_id is not None:
+            recurse_zones = True
+            instances = self.db.instance_get_all_by_reservation(
                                     context, reservation_id)
-
-        children = scheduler_api.call_zone_method(context, "list",
-                                novaclient_collection_name="servers",
-                                reservation_id=reservation_id)
+        elif fixed_ip is not None:
+            try:
+                instances = self.db.fixed_ip_get_instance(context, fixed_ip)
+            except exception.FloatingIpNotFound, e:
+                if not recurse_zones:
+                    raise
+                instances = None
+        elif project_id or not context.is_admin:
+            if not context.project:
+                instances = self.db.instance_get_all_by_user(
+                    context, context.user_id)
+            else:
+                if project_id is None:
+                    project_id = context.project_id
+                instances = self.db.instance_get_all_by_project(
+                    context, project_id)
+        else:
+            instances = self.db.instance_get_all(context)
+
+        if instances is None:
+            instances = []
+        elif not isinstance(instances, list):
+            instances = [instances]
+
+        if not recurse_zones:
+            return instances
+
+        admin_context = context.elevated()
+        children = scheduler_api.call_zone_method(admin_context,
+                "list",
+                novaclient_collection_name="servers",
+                reservation_id=reservation_id,
+                project_id=project_id,
+                fixed_ip=fixed_ip,
+                recurse_zones=True)
 
         for zone, servers in children:
             for server in servers:
@@ -632,32 +672,6 @@
                 instances.append(server._info)
         return instances
 
-    def get_all(self, context, project_id=None, reservation_id=None,
-                fixed_ip=None):
-        """Get all instances filtered by one of the given parameters.
-
-        If there is no filter and the context is an admin, it will retreive
-        all instances in the system.
-        """
-        if reservation_id is not None:
-            return self.get_all_across_zones(context, reservation_id)
-
-        if fixed_ip is not None:
-            return self.db.fixed_ip_get_instance(context, fixed_ip)
-
-        if project_id or not context.is_admin:
-            if not context.project:
-                return self.db.instance_get_all_by_user(
-                    context, context.user_id)
-
-            if project_id is None:
-                project_id = context.project_id
-
-            return self.db.instance_get_all_by_project(
-                context, project_id)
-
-        return self.db.instance_get_all(context)
-
     def _cast_compute_message(self, method, context, instance_id, host=None,
                               params=None):
         """Generic handler for RPC casts to compute.

=== modified file 'nova/scheduler/api.py'
--- nova/scheduler/api.py	2011-06-24 12:01:51 +0000
+++ nova/scheduler/api.py	2011-06-29 22:27:29 +0000
@@ -162,32 +162,53 @@
                     _wrap_method(_process, func), zone_list)]
 
 
-def _issue_novaclient_command(nova, zone, collection, method_name, item_id):
+def _issue_novaclient_command(nova, zone, collection,
+        method_name, *args, **kwargs):
     """Use novaclient to issue command to a single child zone.
-       One of these will be run in parallel for each child zone."""
+       One of these will be run in parallel for each child zone.
+    """
     manager = getattr(nova, collection)
-    result = None
+
+    # NOTE(comstud): This is not ideal, but we have to do this based on
+    # how novaclient is implemented right now.
+    # 'find' is special cased as novaclient requires kwargs for it to
+    # filter on a 'get_all'.
+    # Every other method first needs to do a 'get' on the first argument
+    # passed, which should be a UUID.  If it's 'get' itself that we want,
+    # we just return the result.  Otherwise, we next call the real method
+    # that's wanted... passing other arguments that may or may not exist.
+    if method_name in ['find', 'findall']:
+        try:
+            return getattr(manager, method_name)(**kwargs)
+        except novaclient.NotFound:
+            url = zone.api_url
+            LOG.debug(_("%(collection)s.%(method_name)s didn't find "
+                    "anything matching '%(kwargs)s' on '%(url)s'" %
+                    locals()))
+            return None
+
+    args = list(args)
+    # pop off the UUID to look up
+    item = args.pop(0)
     try:
-        try:
-            result = manager.get(int(item_id))
-        except ValueError, e:
-            result = manager.find(name=item_id)
+        result = manager.get(item)
     except novaclient.NotFound:
         url = zone.api_url
-        LOG.debug(_("%(collection)s '%(item_id)s' not found on '%(url)s'" %
+        LOG.debug(_("%(collection)s '%(item)s' not found on '%(url)s'" %
                                                 locals()))
         return None
 
-    if method_name.lower() not in ['get', 'find']:
-        result = getattr(result, method_name)()
+    if method_name.lower() != 'get':
+        # if we're doing something other than 'get', call it passing args.
+        result = getattr(result, method_name)(*args, **kwargs)
     return result
 
 
-def wrap_novaclient_function(f, collection, method_name, item_id):
-    """Appends collection, method_name and item_id to the incoming
+def wrap_novaclient_function(f, collection, method_name, *args, **kwargs):
+    """Appends collection, method_name and arguments to the incoming
     (nova, zone) call from child_zone_helper."""
     def inner(nova, zone):
-        return f(nova, zone, collection, method_name, item_id)
+        return f(nova, zone, collection, method_name, *args, **kwargs)
 
     return inner
 
@@ -220,7 +241,7 @@
            the wrapped method. (This ensures that zone-local code can
            continue to use integer IDs).
 
-        4. If the item was not found, we delgate the call to a child zone
+        4. If the item was not found, we delegate the call to a child zone
            using the UUID.
     """
     def __init__(self, method_name):

=== modified file 'nova/scheduler/host_filter.py'
--- nova/scheduler/host_filter.py	2011-06-24 14:52:59 +0000
+++ nova/scheduler/host_filter.py	2011-06-29 22:27:29 +0000
@@ -329,8 +329,9 @@
                     'instance_type': <InstanceType dict>}
     """
 
-    def filter_hosts(self, num, request_spec):
+    def filter_hosts(self, topic, request_spec, hosts=None):
         """Filter the full host list (from the ZoneManager)"""
+
         filter_name = request_spec.get('filter', None)
         host_filter = choose_host_filter(filter_name)
 
@@ -341,8 +342,9 @@
         name, query = host_filter.instance_type_to_filter(instance_type)
         return host_filter.filter_hosts(self.zone_manager, query)
 
-    def weigh_hosts(self, num, request_spec, hosts):
+    def weigh_hosts(self, topic, request_spec, hosts):
         """Derived classes must override this method and return
         a lists of hosts in [{weight, hostname}] format.
         """
-        return [dict(weight=1, hostname=host) for host, caps in hosts]
+        return [dict(weight=1, hostname=hostname, capabilities=caps)
+                for hostname, caps in hosts]

=== modified file 'nova/scheduler/least_cost.py'
--- nova/scheduler/least_cost.py	2011-05-17 23:15:31 +0000
+++ nova/scheduler/least_cost.py	2011-06-29 22:27:29 +0000
@@ -48,25 +48,43 @@
     return 1
 
 
-flags.DEFINE_integer('fill_first_cost_fn_weight', 1,
+flags.DEFINE_integer('compute_fill_first_cost_fn_weight', 1,
                      'How much weight to give the fill-first cost function')
 
 
-def fill_first_cost_fn(host):
+def compute_fill_first_cost_fn(host):
     """Prefer hosts that have less ram available, filter_hosts will exclude
     hosts that don't have enough ram"""
     hostname, caps = host
-    free_mem = caps['compute']['host_memory_free']
+    free_mem = caps['host_memory_free']
     return free_mem
 
 
 class LeastCostScheduler(zone_aware_scheduler.ZoneAwareScheduler):
-    def get_cost_fns(self):
+    def __init__(self, *args, **kwargs):
+        self.cost_fns_cache = {}
+        super(LeastCostScheduler, self).__init__(*args, **kwargs)
+
+    def get_cost_fns(self, topic):
         """Returns a list of tuples containing weights and cost functions to
         use for weighing hosts
         """
+
+        if topic in self.cost_fns_cache:
+            return self.cost_fns_cache[topic]
+
         cost_fns = []
         for cost_fn_str in FLAGS.least_cost_scheduler_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
@@ -84,23 +102,23 @@
 
             cost_fns.append((weight, cost_fn))
 
+        self.cost_fns_cache[topic] = cost_fns
         return cost_fns
 
-    def weigh_hosts(self, num, request_spec, hosts):
+    def weigh_hosts(self, topic, request_spec, hosts):
         """Returns a list of dictionaries of form:
-            [ {weight: weight, hostname: hostname} ]"""
-
-        # FIXME(sirp): weigh_hosts should handle more than just instances
-        hostnames = [hostname for hostname, caps in hosts]
-
-        cost_fns = self.get_cost_fns()
+           [ {weight: weight, hostname: hostname, capabilities: capabs} ]
+        """
+
+        cost_fns = self.get_cost_fns(topic)
         costs = weighted_sum(domain=hosts, weighted_fns=cost_fns)
 
         weighted = []
         weight_log = []
-        for cost, hostname in zip(costs, hostnames):
+        for cost, (hostname, caps) in zip(costs, hosts):
             weight_log.append("%s: %s" % (hostname, "%.2f" % cost))
-            weight_dict = dict(weight=cost, hostname=hostname)
+            weight_dict = dict(weight=cost, hostname=hostname,
+                    capabilities=caps)
             weighted.append(weight_dict)
 
         LOG.debug(_("Weighted Costs => %s") % weight_log)
@@ -127,7 +145,8 @@
     weighted_fns - list of weights and functions like:
         [(weight, objective-functions)]
 
-    Returns an unsorted of scores. To pair with hosts do: zip(scores, hosts)
+    Returns an unsorted list of scores. To pair with hosts do:
+        zip(scores, hosts)
     """
     # Table of form:
     #   { domain1: [score1, score2, ..., scoreM]
@@ -150,7 +169,6 @@
     domain_scores = []
     for idx in sorted(score_table):
         elem_score = sum(score_table[idx])
-        elem = domain[idx]
         domain_scores.append(elem_score)
 
     return domain_scores

=== modified file 'nova/scheduler/zone_aware_scheduler.py'
--- nova/scheduler/zone_aware_scheduler.py	2011-06-15 17:21:41 +0000
+++ nova/scheduler/zone_aware_scheduler.py	2011-06-29 22:27:29 +0000
@@ -180,18 +180,22 @@
                                     request_spec, kwargs)
             return None
 
+        num_instances = request_spec.get('num_instances', 1)
+        LOG.debug(_("Attempting to build %(num_instances)d instance(s)") %
+                locals())
+
         # Create build plan and provision ...
         build_plan = self.select(context, request_spec)
         if not build_plan:
             raise driver.NoValidHost(_('No hosts were available'))
 
-        for num in xrange(request_spec['num_instances']):
+        for num in xrange(num_instances):
             if not build_plan:
                 break
 
-            item = build_plan.pop(0)
-            self._provision_resource(context, item, instance_id, request_spec,
-                                    kwargs)
+            build_plan_item = build_plan.pop(0)
+            self._provision_resource(context, build_plan_item, instance_id,
+                                     request_spec, kwargs)
 
         # Returning None short-circuits the routing to Compute (since
         # we've already done it here)
@@ -224,18 +228,36 @@
             raise NotImplemented(_("Zone Aware Scheduler only understands "
                                    "Compute nodes (for now)"))
 
-        #TODO(sandy): how to infer this from OS API params?
-        num_instances = 1
-
-        # Filter local hosts based on requirements ...
-        host_list = self.filter_hosts(num_instances, request_spec)
-
-        # TODO(sirp): weigh_hosts should also be a function of 'topic' or
-        # resources, so that we can apply different objective functions to it
-
-        # then weigh the selected hosts.
-        # weighted = [{weight=weight, name=hostname}, ...]
-        weighted = self.weigh_hosts(num_instances, request_spec, host_list)
+        num_instances = request_spec.get('num_instances', 1)
+        instance_type = request_spec['instance_type']
+
+        weighted = []
+        host_list = None
+
+        for i in xrange(num_instances):
+            # Filter local hosts based on requirements ...
+            #
+            # The first pass through here will pass 'None' as the
+            # host_list.. which tells the filter to build the full
+            # list of hosts.
+            # On a 2nd pass, the filter can modify the host_list with
+            # any updates it needs to make based on resources that
+            # may have been consumed from a previous build..
+            host_list = self.filter_hosts(topic, request_spec, host_list)
+            if not host_list:
+                LOG.warn(_("Filter returned no hosts after processing "
+                        "%(i)d of %(num_instances)d instances") % locals())
+                break
+
+            # then weigh the selected hosts.
+            # weighted = [{weight=weight, hostname=hostname,
+            #              capabilities=capabs}, ...]
+            weights = self.weigh_hosts(topic, request_spec, host_list)
+            weights.sort(key=operator.itemgetter('weight'))
+            best_weight = weights[0]
+            weighted.append(best_weight)
+            self.consume_resources(topic, best_weight['capabilities'],
+                    instance_type)
 
         # Next, tack on the best weights from the child zones ...
         json_spec = json.dumps(request_spec)
@@ -254,18 +276,65 @@
         weighted.sort(key=operator.itemgetter('weight'))
         return weighted
 
-    def filter_hosts(self, num, request_spec):
-        """Derived classes must override this method and return
-           a list of hosts in [(hostname, capability_dict)] format.
-        """
-        # NOTE(sirp): The default logic is the equivalent to AllHostsFilter
-        service_states = self.zone_manager.service_states
-        return [(host, services)
-                for host, services in service_states.iteritems()]
-
-    def weigh_hosts(self, num, request_spec, hosts):
+    def compute_filter(self, hostname, capabilities, request_spec):
+        """Return whether or not we can schedule to this compute node.
+        Derived classes should override this and return True if the host
+        is acceptable for scheduling.
+        """
+        instance_type = request_spec['instance_type']
+        requested_mem = instance_type['memory_mb'] * 1024 * 1024
+        return capabilities['host_memory_free'] >= requested_mem
+
+    def filter_hosts(self, topic, request_spec, host_list=None):
+        """Return a list of hosts which are acceptable for scheduling.
+        Return value should be a list of (hostname, capability_dict)s.
+        Derived classes may override this, but may find the
+        '<topic>_filter' function more appropriate.
+        """
+
+        def _default_filter(self, hostname, capabilities, request_spec):
+            """Default filter function if there's no <topic>_filter"""
+            # NOTE(sirp): The default logic is the equivalent to
+            # AllHostsFilter
+            return True
+
+        filter_func = getattr(self, '%s_filter' % topic, _default_filter)
+
+        if host_list is None:
+            first_run = True
+            host_list = self.zone_manager.service_states.iteritems()
+        else:
+            first_run = False
+
+        filtered_hosts = []
+        for host, services in host_list:
+            if first_run:
+                if topic not in services:
+                    continue
+                services = services[topic]
+            if filter_func(host, services, request_spec):
+                filtered_hosts.append((host, services))
+        return filtered_hosts
+
+    def weigh_hosts(self, topic, request_spec, hosts):
         """Derived classes may override this to provide more sophisticated
         scheduling objectives
         """
         # NOTE(sirp): The default logic is the same as the NoopCostFunction
-        return [dict(weight=1, hostname=host) for host, caps in hosts]
+        return [dict(weight=1, hostname=hostname, capabilities=capabilities)
+                for hostname, capabilities in hosts]
+
+    def compute_consume(self, capabilities, instance_type):
+        """Consume compute resources for selected host"""
+
+        requested_mem = max(instance_type['memory_mb'], 0) * 1024 * 1024
+        capabilities['host_memory_free'] -= requested_mem
+
+    def consume_resources(self, topic, capabilities, instance_type):
+        """Consume resources for a specific host.  'host' is a tuple
+        of the hostname and the services"""
+
+        consume_func = getattr(self, '%s_consume' % topic, None)
+        if not consume_func:
+            return
+        consume_func(capabilities, instance_type)

=== modified file 'nova/tests/scheduler/test_least_cost_scheduler.py'
--- nova/tests/scheduler/test_least_cost_scheduler.py	2011-06-14 01:14:26 +0000
+++ nova/tests/scheduler/test_least_cost_scheduler.py	2011-06-29 22:27:29 +0000
@@ -122,15 +122,16 @@
                     for hostname, caps in hosts]
         self.assertWeights(expected, num, request_spec, hosts)
 
-    def test_fill_first_cost_fn(self):
+    def test_compute_fill_first_cost_fn(self):
         FLAGS.least_cost_scheduler_cost_functions = [
-            'nova.scheduler.least_cost.fill_first_cost_fn',
+            'nova.scheduler.least_cost.compute_fill_first_cost_fn',
         ]
-        FLAGS.fill_first_cost_fn_weight = 1
+        FLAGS.compute_fill_first_cost_fn_weight = 1
 
         num = 1
-        request_spec = {}
-        hosts = self.sched.filter_hosts(num, request_spec)
+        instance_type = {'memory_mb': 1024}
+        request_spec = {'instance_type': instance_type}
+        hosts = self.sched.filter_hosts('compute', request_spec, None)
 
         expected = []
         for idx, (hostname, caps) in enumerate(hosts):

=== modified file 'nova/tests/scheduler/test_scheduler.py'
--- nova/tests/scheduler/test_scheduler.py	2011-06-24 12:01:51 +0000
+++ nova/tests/scheduler/test_scheduler.py	2011-06-29 22:27:29 +0000
@@ -1074,7 +1074,7 @@
 
         self.assertEquals(api._issue_novaclient_command(
                     FakeNovaClient(FakeServerCollection()),
-                    zone, "servers", "find", "name").b, 22)
+                    zone, "servers", "find", name="test").b, 22)
 
         self.assertEquals(api._issue_novaclient_command(
                     FakeNovaClient(FakeServerCollection()),
@@ -1088,7 +1088,7 @@
 
         self.assertEquals(api._issue_novaclient_command(
                     FakeNovaClient(FakeEmptyServerCollection()),
-                    zone, "servers", "find", "name"), None)
+                    zone, "servers", "find", name="test"), None)
 
         self.assertEquals(api._issue_novaclient_command(
                     FakeNovaClient(FakeEmptyServerCollection()),

=== modified file 'nova/tests/scheduler/test_zone_aware_scheduler.py'
--- nova/tests/scheduler/test_zone_aware_scheduler.py	2011-06-14 01:14:26 +0000
+++ nova/tests/scheduler/test_zone_aware_scheduler.py	2011-06-29 22:27:29 +0000
@@ -55,29 +55,21 @@
 
 
 class FakeZoneAwareScheduler(zone_aware_scheduler.ZoneAwareScheduler):
-    def filter_hosts(self, num, specs):
-        # NOTE(sirp): this is returning [(hostname, services)]
-        return self.zone_manager.service_states.items()
-
-    def weigh_hosts(self, num, specs, hosts):
-        fake_weight = 99
-        weighted = []
-        for hostname, caps in hosts:
-            weighted.append(dict(weight=fake_weight, name=hostname))
-        return weighted
+    # No need to stub anything at the moment
+    pass
 
 
 class FakeZoneManager(zone_manager.ZoneManager):
     def __init__(self):
         self.service_states = {
             'host1': {
-                'compute': {'ram': 1000},
+                'compute': {'host_memory_free': 1073741824},
             },
             'host2': {
-                'compute': {'ram': 2000},
+                'compute': {'host_memory_free': 2147483648},
             },
             'host3': {
-                'compute': {'ram': 3000},
+                'compute': {'host_memory_free': 3221225472},
             },
         }
 
@@ -154,8 +146,8 @@
 
     def test_zone_aware_scheduler(self):
         """
-        Create a nested set of FakeZones, ensure that a select call returns the
-        appropriate build plan.
+        Create a nested set of FakeZones, try to build multiple instances
+        and ensure that a select call returns the appropriate build plan.
         """
         sched = FakeZoneAwareScheduler()
         self.stubs.Set(sched, '_call_zone_method', fake_call_zone_method)
@@ -164,13 +156,17 @@
         sched.set_zone_manager(zm)
 
         fake_context = {}
-        build_plan = sched.select(fake_context, {})
-
-        self.assertEqual(15, len(build_plan))
-
-        hostnames = [plan_item['name']
-                     for plan_item in build_plan if 'name' in plan_item]
-        self.assertEqual(3, len(hostnames))
+        build_plan = sched.select(fake_context,
+                {'instance_type': {'memory_mb': 512},
+                    'num_instances': 4})
+
+        # 4 from local zones, 12 from remotes
+        self.assertEqual(16, len(build_plan))
+
+        hostnames = [plan_item['hostname']
+                     for plan_item in build_plan if 'hostname' in plan_item]
+        # 4 local hosts
+        self.assertEqual(4, len(hostnames))
 
     def test_empty_zone_aware_scheduler(self):
         """
@@ -185,8 +181,7 @@
         fake_context = {}
         self.assertRaises(driver.NoValidHost, sched.schedule_run_instance,
                           fake_context, 1,
-                          dict(host_filter=None,
-                               request_spec={'instance_type': {}}))
+                          dict(host_filter=None, instance_type={}))
 
     def test_schedule_do_not_schedule_with_hint(self):
         """

=== modified file 'nova/tests/test_utils.py'
--- nova/tests/test_utils.py	2011-06-24 12:01:51 +0000
+++ nova/tests/test_utils.py	2011-06-29 22:27:29 +0000
@@ -276,6 +276,19 @@
         result = utils.parse_server_string('www.exa:mple.com:8443')
         self.assertEqual(('', ''), result)
 
+    def test_bool_from_str(self):
+        self.assertTrue(utils.bool_from_str('1'))
+        self.assertTrue(utils.bool_from_str('2'))
+        self.assertTrue(utils.bool_from_str('-1'))
+        self.assertTrue(utils.bool_from_str('true'))
+        self.assertTrue(utils.bool_from_str('True'))
+        self.assertTrue(utils.bool_from_str('tRuE'))
+        self.assertFalse(utils.bool_from_str('False'))
+        self.assertFalse(utils.bool_from_str('false'))
+        self.assertFalse(utils.bool_from_str('0'))
+        self.assertFalse(utils.bool_from_str(None))
+        self.assertFalse(utils.bool_from_str('junk'))
+
 
 class IsUUIDLikeTestCase(test.TestCase):
     def assertUUIDLike(self, val, expected):

=== modified file 'nova/utils.py'
--- nova/utils.py	2011-06-28 20:53:45 +0000
+++ nova/utils.py	2011-06-29 22:27:29 +0000
@@ -772,6 +772,17 @@
     return (len(val) == 36) and (val.count('-') == 4)
 
 
+def bool_from_str(val):
+    """Convert a string representation of a bool into a bool value"""
+
+    if not val:
+        return False
+    try:
+        return True if int(val) else False
+    except ValueError:
+        return val.lower() == 'true'
+
+
 class Bootstrapper(object):
     """Provides environment bootstrapping capabilities for entry points."""
 

=== modified file 'tools/pip-requires'
--- tools/pip-requires	2011-06-28 15:13:52 +0000
+++ tools/pip-requires	2011-06-29 22:27:29 +0000
@@ -9,7 +9,7 @@
 carrot==0.10.5
 eventlet
 lockfile==0.8
-python-novaclient==2.5.3
+python-novaclient==2.5.7
 python-daemon==1.5.5
 python-gflags==1.3
 redis==2.0.0