In this branch we are forwarding incoming requests to child zones when the requested resource is not found in the current zone.

For example: If 'nova pause 123' is issued against Zone 1, but instance 123 does not live in Zone 1, the call will be forwarded to all child zones hoping someone can deal with it.

NOTE: This currently only works with OpenStack API requests and routing checks are only being done against Compute/instance_id checks.
Specifically:
* servers.get/pause/unpause/diagnostics/suspend/resume/rescue/unrescue/delete
* servers.create is pending for distributed scheduler
* servers.get_all will get added early in Diablo.

What I've been doing for testing:
1. Set up a Nova deployment in a VM (Zone0)
2. Clone the VM and set --zone_name=zone1 (and change all the IP addresses to the new address in nova.conf, glance.conf and novarc)
3. Set --enable_zone_routing=true on all zones
4. use the --connection_type=fake driver for compute to keep things easy
5. Add Zone1 as a child of Zone0 (nova zone-add)

(make sure the instance id's are different in each zone)

Example of calls being sent to child zones:
http://paste.openstack.org/show/964/

nova/api/openstack/servers.py

@@ -37,6 +37,7 @@ from nova.auth import manager as auth_manager
 from nova.compute import instance_types
 from nova.compute import power_state
 import nova.api.openstack
+from nova.scheduler import api as scheduler_api
 
 
 LOG = logging.getLogger('server')
@@ -87,15 +88,18 @@ class Controller(wsgi.Controller):
                 for inst in limited_list]
         return dict(servers=servers)
 
+    @scheduler_api.redirect_handler
     def show(self, req, id):
         """ Returns server details by server id """
         try:
-            instance = self.compute_api.get(req.environ['nova.context'], id)
+            instance = self.compute_api.routing_get(
+                req.environ['nova.context'], id)
             builder = self._get_view_builder(req)
             return builder.build(instance, is_detail=True)
         except exception.NotFound:
             return faults.Fault(exc.HTTPNotFound())
 
+    @scheduler_api.redirect_handler
     def delete(self, req, id):
         """ Destroys a server """
         try:
@@ -226,6 +230,7 @@ class Controller(wsgi.Controller):
         # if the original error is okay, just reraise it
         raise error
 
+    @scheduler_api.redirect_handler
     def update(self, req, id):
         """ Updates the server name or password """
         if len(req.body) == 0:
@@ -251,6 +256,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPNotFound())
         return exc.HTTPNoContent()
 
+    @scheduler_api.redirect_handler
     def action(self, req, id):
         """Multi-purpose method used to reboot, rebuild, or
         resize a server"""
@@ -316,6 +322,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def lock(self, req, id):
         """
         lock the instance with id
@@ -331,6 +338,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def unlock(self, req, id):
         """
         unlock the instance with id
@@ -346,6 +354,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def get_lock(self, req, id):
         """
         return the boolean state of (instance with id)'s lock
@@ -360,6 +369,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def reset_network(self, req, id):
         """
         Reset networking on an instance (admin only).
@@ -374,6 +384,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def inject_network_info(self, req, id):
         """
         Inject network info for an instance (admin only).
@@ -388,6 +399,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def pause(self, req, id):
         """ Permit Admins to Pause the server. """
         ctxt = req.environ['nova.context']
@@ -399,6 +411,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def unpause(self, req, id):
         """ Permit Admins to Unpause the server. """
         ctxt = req.environ['nova.context']
@@ -410,6 +423,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def suspend(self, req, id):
         """permit admins to suspend the server"""
         context = req.environ['nova.context']
@@ -421,6 +435,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def resume(self, req, id):
         """permit admins to resume the server from suspend"""
         context = req.environ['nova.context']
@@ -432,6 +447,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def rescue(self, req, id):
         """Permit users to rescue the server."""
         context = req.environ["nova.context"]
@@ -443,6 +459,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def unrescue(self, req, id):
         """Permit users to unrescue the server."""
         context = req.environ["nova.context"]
@@ -454,6 +471,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPUnprocessableEntity())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def get_ajax_console(self, req, id):
         """ Returns a url to an instance's ajaxterm console. """
         try:
@@ -463,6 +481,7 @@ class Controller(wsgi.Controller):
             return faults.Fault(exc.HTTPNotFound())
         return exc.HTTPAccepted()
 
+    @scheduler_api.redirect_handler
     def diagnostics(self, req, id):
         """Permit Admins to retrieve server diagnostics."""
         ctxt = req.environ["nova.context"]

nova/api/openstack/zones.py

@@ -17,6 +17,7 @@ import common
 
 from nova import db
 from nova import flags
+from nova import log as logging
 from nova import wsgi
 from nova.scheduler import api
 
@@ -38,7 +39,8 @@ def _exclude_keys(item, keys):
 
 
 def _scrub_zone(zone):
-    return _filter_keys(zone, ('id', 'api_url'))
+    return _exclude_keys(zone, ('username', 'password', 'created_at',
+                    'deleted', 'deleted_at', 'updated_at'))
 
 
 class Controller(wsgi.Controller):
@@ -53,12 +55,8 @@ class Controller(wsgi.Controller):
         # Ask the ZoneManager in the Scheduler for most recent data,
         # or fall-back to the database ...
         items = api.get_zone_list(req.environ['nova.context'])
-        if not items:
-            items = db.zone_get_all(req.environ['nova.context'])
-
         items = common.limited(items, req)
-        items = [_exclude_keys(item, ['username', 'password'])
+        items = [_scrub_zone(item) for item in items]
-                      for item in items]
         return dict(zones=items)
 
     def detail(self, req):
@@ -81,23 +79,23 @@ class Controller(wsgi.Controller):
     def show(self, req, id):
         """Return data about the given zone id"""
         zone_id = int(id)
-        zone = db.zone_get(req.environ['nova.context'], zone_id)
+        zone = api.zone_get(req.environ['nova.context'], zone_id)
         return dict(zone=_scrub_zone(zone))
 
     def delete(self, req, id):
         zone_id = int(id)
-        db.zone_delete(req.environ['nova.context'], zone_id)
+        api.zone_delete(req.environ['nova.context'], zone_id)
         return {}
 
     def create(self, req):
         context = req.environ['nova.context']
         env = self._deserialize(req.body, req.get_content_type())
-        zone = db.zone_create(context, env["zone"])
+        zone = api.zone_create(context, env["zone"])
         return dict(zone=_scrub_zone(zone))
 
     def update(self, req, id):
         context = req.environ['nova.context']
         env = self._deserialize(req.body, req.get_content_type())
         zone_id = int(id)
-        zone = db.zone_update(context, zone_id, env["zone"])
+        zone = api.zone_update(context, zone_id, env["zone"])
         return dict(zone=_scrub_zone(zone))

nova/compute/api.py

@@ -34,6 +34,7 @@ from nova import rpc
 from nova import utils
 from nova import volume
 from nova.compute import instance_types
+from nova.scheduler import api as scheduler_api
 from nova.db import base
 
 FLAGS = flags.FLAGS
@@ -352,6 +353,7 @@ class API(base.Base):
         rv = self.db.instance_update(context, instance_id, kwargs)
         return dict(rv.iteritems())
 
+    @scheduler_api.reroute_compute("delete")
     def delete(self, context, instance_id):
         LOG.debug(_("Going to try to terminate %s"), instance_id)
         try:
@@ -384,6 +386,13 @@ class API(base.Base):
         rv = self.db.instance_get(context, instance_id)
         return dict(rv.iteritems())
 
+    @scheduler_api.reroute_compute("get")
+    def routing_get(self, context, instance_id):
+        """Use this method instead of get() if this is the only
+           operation you intend to to. It will route to novaclient.get
+           if the instance is not found."""
+        return self.get(context, instance_id)
+
     def get_all(self, context, project_id=None, reservation_id=None,
                 fixed_ip=None):
         """Get all instances, possibly filtered by one of the
@@ -527,14 +536,17 @@ class API(base.Base):
                               "instance_id": instance_id,
                               "flavor_id": flavor_id}})
 
+    @scheduler_api.reroute_compute("pause")
     def pause(self, context, instance_id):
         """Pause the given instance."""
         self._cast_compute_message('pause_instance', context, instance_id)
 
+    @scheduler_api.reroute_compute("unpause")
     def unpause(self, context, instance_id):
         """Unpause the given instance."""
         self._cast_compute_message('unpause_instance', context, instance_id)
 
+    @scheduler_api.reroute_compute("diagnostics")
     def get_diagnostics(self, context, instance_id):
         """Retrieve diagnostics for the given instance."""
         return self._call_compute_message(
@@ -546,18 +558,22 @@ class API(base.Base):
         """Retrieve actions for the given instance."""
         return self.db.instance_get_actions(context, instance_id)
 
+    @scheduler_api.reroute_compute("suspend")
     def suspend(self, context, instance_id):
         """suspend the instance with instance_id"""
         self._cast_compute_message('suspend_instance', context, instance_id)
 
+    @scheduler_api.reroute_compute("resume")
     def resume(self, context, instance_id):
         """resume the instance with instance_id"""
         self._cast_compute_message('resume_instance', context, instance_id)
 
+    @scheduler_api.reroute_compute("rescue")
     def rescue(self, context, instance_id):
         """Rescue the given instance."""
         self._cast_compute_message('rescue_instance', context, instance_id)
 
+    @scheduler_api.reroute_compute("unrescue")
     def unrescue(self, context, instance_id):
         """Unrescue the given instance."""
         self._cast_compute_message('unrescue_instance', context, instance_id)
@@ -573,7 +589,6 @@ class API(base.Base):
 
     def get_ajax_console(self, context, instance_id):
         """Get a url to an AJAX Console"""
-        instance = self.get(context, instance_id)
         output = self._call_compute_message('get_ajax_console',
                                             context,
                                             instance_id)

nova/db/api.py

@@ -71,6 +71,7 @@ class NoMoreTargets(exception.Error):
     """No more available blades"""
     pass
 
+
 ###################
 
 

nova/scheduler/api.py

@@ -17,11 +17,21 @@
 Handles all requests relating to schedulers.
 """
 
+import novaclient
+
+from nova import db
+from nova import exception
 from nova import flags
 from nova import log as logging
 from nova import rpc
 
+from eventlet import greenpool
+
 FLAGS = flags.FLAGS
+flags.DEFINE_bool('enable_zone_routing',
+    False,
+    'When True, routing to child zones will occur.')
+
 LOG = logging.getLogger('nova.scheduler.api')
 
 
@@ -45,9 +55,27 @@ def get_zone_list(context):
     items = _call_scheduler('get_zone_list', context)
     for item in items:
         item['api_url'] = item['api_url'].replace('\\/', '/')
+    if not items:
+        items = db.zone_get_all(context)
     return items
 
 
+def zone_get(context, zone_id):
+    return db.zone_get(context, zone_id)
+
+
+def zone_delete(context, zone_id):
+    return db.zone_delete(context, zone_id)
+
+
+def zone_create(context, data):
+    return db.zone_create(context, data)
+
+
+def zone_update(context, zone_id, data):
+    return db.zone_update(context, zone_id, data)
+
+
 def get_zone_capabilities(context, service=None):
     """Returns a dict of key, value capabilities for this zone,
        or for a particular class of services running in this zone."""
@@ -62,3 +90,152 @@ def update_service_capabilities(context, service_name, host, capabilities):
                   args=dict(service_name=service_name, host=host,
                             capabilities=capabilities))
     return rpc.fanout_cast(context, 'scheduler', kwargs)
+
+
+def _wrap_method(function, self):
+    """Wrap method to supply self."""
+    def _wrap(*args, **kwargs):
+        return function(self, *args, **kwargs)
+    return _wrap
+
+
+def _process(func, zone):
+    """Worker stub for green thread pool. Give the worker
+    an authenticated nova client and zone info."""
+    nova = novaclient.OpenStack(zone.username, zone.password, zone.api_url)
+    nova.authenticate()
+    return func(nova, zone)
+
+
+def child_zone_helper(zone_list, func):
+    """Fire off a command to each zone in the list.
+    The return is [novaclient return objects] from each child zone.
+    For example, if you are calling server.pause(), the list will
+    be whatever the response from server.pause() is. One entry
+    per child zone called."""
+    green_pool = greenpool.GreenPool()
+    return [result for result in green_pool.imap(
+                    _wrap_method(_process, func), zone_list)]
+
+
+def _issue_novaclient_command(nova, zone, collection, method_name, item_id):
+    """Use novaclient to issue command to a single child zone.
+       One of these will be run in parallel for each child zone."""
+    manager = getattr(nova, collection)
+    result = None
+    try:
+        try:
+            result = manager.get(int(item_id))
+        except ValueError, e:
+            result = manager.find(name=item_id)
+    except novaclient.NotFound:
+        url = zone.api_url
+        LOG.debug(_("%(collection)s '%(item_id)s' not found on '%(url)s'" %
+                                                locals()))
+        return None
+
+    if method_name.lower() not in ['get', 'find']:
+        result = getattr(result, method_name)()
+    return result
+
+
+def wrap_novaclient_function(f, collection, method_name, item_id):
+    """Appends collection, method_name and item_id to the incoming
+    (nova, zone) call from child_zone_helper."""
+    def inner(nova, zone):
+        return f(nova, zone, collection, method_name, item_id)
+
+    return inner
+
+
+class RedirectResult(exception.Error):
+    """Used to the HTTP API know that these results are pre-cooked
+    and they can be returned to the caller directly."""
+    def __init__(self, results):
+        self.results = results
+        super(RedirectResult, self).__init__(
+               message=_("Uncaught Zone redirection exception"))
+
+
+class reroute_compute(object):
+    """Decorator used to indicate that the method should
+       delegate the call the child zones if the db query
+       can't find anything."""
+    def __init__(self, method_name):
+        self.method_name = method_name
+
+    def __call__(self, f):
+        def wrapped_f(*args, **kwargs):
+            collection, context, item_id = \
+                            self.get_collection_context_and_id(args, kwargs)
+            try:
+                # Call the original function ...
+                return f(*args, **kwargs)
+            except exception.InstanceNotFound, e:
+                LOG.debug(_("Instance %(item_id)s not found "
+                                    "locally: '%(e)s'" % locals()))
+
+                if not FLAGS.enable_zone_routing:
+                    raise
+
+                zones = db.zone_get_all(context)
+                if not zones:
+                    raise
+
+                # Ask the children to provide an answer ...
+                LOG.debug(_("Asking child zones ..."))
+                result = self._call_child_zones(zones,
+                            wrap_novaclient_function(_issue_novaclient_command,
+                                   collection, self.method_name, item_id))
+                # Scrub the results and raise another exception
+                # so the API layers can bail out gracefully ...
+                raise RedirectResult(self.unmarshall_result(result))
+        return wrapped_f
+
+    def _call_child_zones(self, zones, function):
+        """Ask the child zones to perform this operation.
+        Broken out for testing."""
+        return child_zone_helper(zones, function)
+
+    def get_collection_context_and_id(self, args, kwargs):
+        """Returns a tuple of (novaclient collection name, security
+           context and resource id. Derived class should override this."""
+        context = kwargs.get('context', None)
+        instance_id = kwargs.get('instance_id', None)
+        if len(args) > 0 and not context:
+            context = args[1]
+        if len(args) > 1 and not instance_id:
+            instance_id = args[2]
+        return ("servers", context, instance_id)
+
+    def unmarshall_result(self, zone_responses):
+        """Result is a list of responses from each child zone.
+        Each decorator derivation is responsible to turning this
+        into a format expected by the calling method. For
+        example, this one is expected to return a single Server
+        dict {'server':{k:v}}. Others may return a list of them, like
+        {'servers':[{k,v}]}"""
+        reduced_response = []
+        for zone_response in zone_responses:
+            if not zone_response:
+                continue
+
+            server = zone_response.__dict__
+
+            for k in server.keys():
+                if k[0] == '_' or k == 'manager':
+                    del server[k]
+
+            reduced_response.append(dict(server=server))
+        if reduced_response:
+            return reduced_response[0]  # first for now.
+        return {}
+
+
+def redirect_handler(f):
+    def new_f(*args, **kwargs):
+        try:
+            return f(*args, **kwargs)
+        except RedirectResult, e:
+            return e.results
+    return new_f

nova/scheduler/zone_manager.py

@@ -58,8 +58,9 @@ class ZoneState(object):
            child zone."""
         self.last_seen = datetime.now()
         self.attempt = 0
-        self.name = zone_metadata["name"]
+        self.name = zone_metadata.get("name", "n/a")
-        self.capabilities = zone_metadata["capabilities"]
+        self.capabilities = ", ".join(["%s=%s" % (k, v)
+                        for k, v in zone_metadata.iteritems() if k != 'name'])
         self.is_active = True
 
     def to_dict(self):
@@ -104,7 +105,7 @@ class ZoneManager(object):
     """Keeps the zone states updated."""
     def __init__(self):
         self.last_zone_db_check = datetime.min
-        self.zone_states = {}
+        self.zone_states = {}  # { <zone_id> : ZoneState }
         self.service_states = {}  # { <service> : { <host> : { cap k : v }}}
         self.green_pool = greenpool.GreenPool()
 

nova/tests/test_scheduler.py

@@ -21,6 +21,9 @@ Tests For Scheduler
 
 import datetime
 import mox
+import novaclient.exceptions
+import stubout
+import webob
 
 from mox import IgnoreArg
 from nova import context
@@ -32,6 +35,7 @@ from nova import test
 from nova import rpc
 from nova import utils
 from nova.auth import manager as auth_manager
+from nova.scheduler import api
 from nova.scheduler import manager
 from nova.scheduler import driver
 from nova.compute import power_state
@@ -937,3 +941,160 @@ class SimpleDriverTestCase(test.TestCase):
         db.instance_destroy(self.context, instance_id)
         db.service_destroy(self.context, s_ref['id'])
         db.service_destroy(self.context, s_ref2['id'])
+
+
+class FakeZone(object):
+    def __init__(self, api_url, username, password):
+        self.api_url = api_url
+        self.username = username
+        self.password = password
+
+
+def zone_get_all(context):
+    return [
+                FakeZone('http://example.com', 'bob', 'xxx'),
+           ]
+
+
+class FakeRerouteCompute(api.reroute_compute):
+    def _call_child_zones(self, zones, function):
+        return []
+
+    def get_collection_context_and_id(self, args, kwargs):
+        return ("servers", None, 1)
+
+    def unmarshall_result(self, zone_responses):
+        return dict(magic="found me")
+
+
+def go_boom(self, context, instance):
+    raise exception.InstanceNotFound("boom message", instance)
+
+
+def found_instance(self, context, instance):
+    return dict(name='myserver')
+
+
+class FakeResource(object):
+    def __init__(self, attribute_dict):
+        for k, v in attribute_dict.iteritems():
+            setattr(self, k, v)
+
+    def pause(self):
+        pass
+
+
+class ZoneRedirectTest(test.TestCase):
+    def setUp(self):
+        super(ZoneRedirectTest, self).setUp()
+        self.stubs = stubout.StubOutForTesting()
+
+        self.stubs.Set(db, 'zone_get_all', zone_get_all)
+
+        self.enable_zone_routing = FLAGS.enable_zone_routing
+        FLAGS.enable_zone_routing = True
+
+    def tearDown(self):
+        self.stubs.UnsetAll()
+        FLAGS.enable_zone_routing = self.enable_zone_routing
+        super(ZoneRedirectTest, self).tearDown()
+
+    def test_trap_found_locally(self):
+        decorator = FakeRerouteCompute("foo")
+        try:
+            result = decorator(found_instance)(None, None, 1)
+        except api.RedirectResult, e:
+            self.fail(_("Successful database hit should succeed"))
+
+    def test_trap_not_found_locally(self):
+        decorator = FakeRerouteCompute("foo")
+        try:
+            result = decorator(go_boom)(None, None, 1)
+            self.assertFail(_("Should have rerouted."))
+        except api.RedirectResult, e:
+            self.assertEquals(e.results['magic'], 'found me')
+
+    def test_routing_flags(self):
+        FLAGS.enable_zone_routing = False
+        decorator = FakeRerouteCompute("foo")
+        try:
+            result = decorator(go_boom)(None, None, 1)
+            self.assertFail(_("Should have thrown exception."))
+        except exception.InstanceNotFound, e:
+            self.assertEquals(e.message, 'boom message')
+
+    def test_get_collection_context_and_id(self):
+        decorator = api.reroute_compute("foo")
+        self.assertEquals(decorator.get_collection_context_and_id(
+            (None, 10, 20), {}), ("servers", 10, 20))
+        self.assertEquals(decorator.get_collection_context_and_id(
+            (None, 11,),  dict(instance_id=21)), ("servers", 11, 21))
+        self.assertEquals(decorator.get_collection_context_and_id(
+            (None,), dict(context=12, instance_id=22)), ("servers", 12, 22))
+
+    def test_unmarshal_single_server(self):
+        decorator = api.reroute_compute("foo")
+        self.assertEquals(decorator.unmarshall_result([]), {})
+        self.assertEquals(decorator.unmarshall_result(
+                [FakeResource(dict(a=1, b=2)), ]),
+                dict(server=dict(a=1, b=2)))
+        self.assertEquals(decorator.unmarshall_result(
+                [FakeResource(dict(a=1, _b=2)), ]),
+                dict(server=dict(a=1,)))
+        self.assertEquals(decorator.unmarshall_result(
+                [FakeResource(dict(a=1, manager=2)), ]),
+                dict(server=dict(a=1,)))
+        self.assertEquals(decorator.unmarshall_result(
+                [FakeResource(dict(_a=1, manager=2)), ]),
+                dict(server={}))
+
+
+class FakeServerCollection(object):
+    def get(self, instance_id):
+        return FakeResource(dict(a=10, b=20))
+
+    def find(self, name):
+        return FakeResource(dict(a=11, b=22))
+
+
+class FakeEmptyServerCollection(object):
+    def get(self, f):
+        raise novaclient.NotFound(1)
+
+    def find(self, name):
+        raise novaclient.NotFound(2)
+
+
+class FakeNovaClient(object):
+    def __init__(self, collection):
+        self.servers = collection
+
+
+class DynamicNovaClientTest(test.TestCase):
+    def test_issue_novaclient_command_found(self):
+        zone = FakeZone('http://example.com', 'bob', 'xxx')
+        self.assertEquals(api._issue_novaclient_command(
+                    FakeNovaClient(FakeServerCollection()),
+                    zone, "servers", "get", 100).a, 10)
+
+        self.assertEquals(api._issue_novaclient_command(
+                    FakeNovaClient(FakeServerCollection()),
+                    zone, "servers", "find", "name").b, 22)
+
+        self.assertEquals(api._issue_novaclient_command(
+                    FakeNovaClient(FakeServerCollection()),
+                    zone, "servers", "pause", 100), None)
+
+    def test_issue_novaclient_command_not_found(self):
+        zone = FakeZone('http://example.com', 'bob', 'xxx')
+        self.assertEquals(api._issue_novaclient_command(
+                    FakeNovaClient(FakeEmptyServerCollection()),
+                    zone, "servers", "get", 100), None)
+
+        self.assertEquals(api._issue_novaclient_command(
+                    FakeNovaClient(FakeEmptyServerCollection()),
+                    zone, "servers", "find", "name"), None)
+
+        self.assertEquals(api._issue_novaclient_command(
+                    FakeNovaClient(FakeEmptyServerCollection()),
+                    zone, "servers", "any", "name"), None)