diff --git a/nova/baserpc.py b/nova/baserpc.py
index 1cb474209e83..b166cb40033c 100644
--- a/nova/baserpc.py
+++ b/nova/baserpc.py
@@ -18,11 +18,20 @@
 Base RPC client and server common to all services.
 """
 
+from oslo.config import cfg
+
 from nova.openstack.common import jsonutils
 from nova.openstack.common import rpc
 import nova.openstack.common.rpc.proxy as rpc_proxy
 
 
+CONF = cfg.CONF
+rpcapi_cap_opt = cfg.StrOpt('baseapi',
+        default=None,
+        help='Set a version cap for messages sent to the base api in any '
+             'service')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 _NAMESPACE = 'baseapi'
 
 
@@ -45,9 +54,16 @@ class BaseAPI(rpc_proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        # baseapi was added in havana
+    }
+
     def __init__(self, topic):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.baseapi,
+                                               CONF.upgrade_levels.baseapi)
         super(BaseAPI, self).__init__(topic=topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
         self.namespace = _NAMESPACE
 
     def ping(self, context, arg, timeout=None):
diff --git a/nova/cells/rpc_driver.py b/nova/cells/rpc_driver.py
index 0dcf1184cf40..6b11e0f058cc 100644
--- a/nova/cells/rpc_driver.py
+++ b/nova/cells/rpc_driver.py
@@ -34,6 +34,11 @@ CONF = cfg.CONF
 CONF.register_opts(cell_rpc_driver_opts, group='cells')
 CONF.import_opt('call_timeout', 'nova.cells.opts', group='cells')
 
+rpcapi_cap_opt = cfg.StrOpt('intercell',
+        default=None,
+        help='Set a version cap for messages sent between cells services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 _CELL_TO_CELL_RPC_API_VERSION = '1.0'
 
 
@@ -103,9 +108,21 @@ class InterCellRPCAPI(rpc_proxy.RpcProxy):
 
     API version history:
         1.0 - Initial version.
+
+        ... Grizzly supports message version 1.0.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.0.
     """
+
+    VERSION_ALIASES = {
+        'grizzly': '1.0',
+    }
+
     def __init__(self, default_version):
-        super(InterCellRPCAPI, self).__init__(None, default_version)
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.intercell,
+                                               CONF.upgrade_levels.intercell)
+        super(InterCellRPCAPI, self).__init__(None, default_version,
+                version_cap=version_cap)
 
     @staticmethod
     def _get_server_params_for_cell(next_hop):
diff --git a/nova/cells/rpcapi.py b/nova/cells/rpcapi.py
index 767498291a26..e65d8f4906d4 100644
--- a/nova/cells/rpcapi.py
+++ b/nova/cells/rpcapi.py
@@ -33,6 +33,11 @@ CONF = cfg.CONF
 CONF.import_opt('enable', 'nova.cells.opts', group='cells')
 CONF.import_opt('topic', 'nova.cells.opts', group='cells')
 
+rpcapi_cap_opt = cfg.StrOpt('cells',
+        default=None,
+        help='Set a version cap for messages sent to local cells services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class CellsAPI(rpc_proxy.RpcProxy):
     '''Cells client-side RPC API
@@ -49,15 +54,27 @@ class CellsAPI(rpc_proxy.RpcProxy):
         1.5 - Adds actions_get(), action_get_by_request_id(), and
               action_events_get()
         1.6 - Adds consoleauth_delete_tokens() and validate_console_port()
+
+        ... Grizzly supports message version 1.6.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.6.
+
         1.7 - Adds service_update()
         1.8 - Adds build_instances(), deprecates schedule_run_instance()
         1.9 - Adds get_capacities()
     '''
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '1.6'
+    }
+
     def __init__(self):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.cells,
+                                               CONF.upgrade_levels.cells)
         super(CellsAPI, self).__init__(topic=CONF.cells.topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
 
     def cast_compute_api_method(self, ctxt, cell_name, method,
             *args, **kwargs):
diff --git a/nova/cert/rpcapi.py b/nova/cert/rpcapi.py
index 505efe75f83d..f4311b517bf0 100644
--- a/nova/cert/rpcapi.py
+++ b/nova/cert/rpcapi.py
@@ -31,6 +31,11 @@ rpcapi_opts = [
 CONF = cfg.CONF
 CONF.register_opts(rpcapi_opts)
 
+rpcapi_cap_opt = cfg.StrOpt('cert',
+        default=None,
+        help='Set a version cap for messages sent to cert services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class CertAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     '''Client side of the cert rpc API.
@@ -39,6 +44,10 @@ class CertAPI(nova.openstack.common.rpc.proxy.RpcProxy):
 
         1.0 - Initial version.
         1.1 - Added get_backdoor_port()
+
+        ... Grizzly supports message version 1.1.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.1.
     '''
 
     #
@@ -51,10 +60,17 @@ class CertAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '1.1',
+    }
+
     def __init__(self):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.cert,
+                                               CONF.upgrade_levels.cert)
         super(CertAPI, self).__init__(
                 topic=CONF.cert_topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
 
     def revoke_certs_by_user(self, ctxt, user_id):
         return self.call(ctxt, self.make_msg('revoke_certs_by_user',
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index 98e90cf24eff..30db6010fb4b 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -36,6 +36,11 @@ rpcapi_opts = [
 CONF = cfg.CONF
 CONF.register_opts(rpcapi_opts)
 
+rpcapi_cap_opt = cfg.StrOpt('compute',
+        default=None,
+        help='Set a version cap for messages sent to compute services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 def _compute_topic(topic, ctxt, host, instance):
     '''Get the topic to use for a message.
@@ -167,6 +172,11 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                vnc on the correct port
         2.27 - Adds 'reservations' to terminate_instance() and
                soft_delete_instance()
+
+        ... Grizzly supports message version 2.27.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 2.27.
+
         2.28 - Adds check_instance_shared_storage()
         2.29 - Made start_instance() and stop_instance() take new-world
                instance objects
@@ -182,11 +192,18 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '2.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '2.27',
+    }
+
     def __init__(self):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.compute,
+                                               CONF.upgrade_levels.compute)
         super(ComputeAPI, self).__init__(
                 topic=CONF.compute_topic,
                 default_version=self.BASE_RPC_API_VERSION,
-                serializer=objects_base.NovaObjectSerializer())
+                serializer=objects_base.NovaObjectSerializer(),
+                version_cap=version_cap)
 
     def add_aggregate_host(self, ctxt, aggregate, host_param, host,
                            slave_info=None):
diff --git a/nova/conductor/rpcapi.py b/nova/conductor/rpcapi.py
index c9b1c0af701e..bb66ca8b2bb0 100644
--- a/nova/conductor/rpcapi.py
+++ b/nova/conductor/rpcapi.py
@@ -22,6 +22,11 @@ import nova.openstack.common.rpc.proxy
 
 CONF = cfg.CONF
 
+rpcapi_cap_opt = cfg.StrOpt('conductor',
+        default=None,
+        help='Set a version cap for messages sent to conductor services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class ConductorAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     """Client side of the conductor RPC API
@@ -88,6 +93,11 @@ class ConductorAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     1.47 - Added columns_to_join to instance_get_all_by_host and
                  instance_get_all_by_filters
     1.48 - Added compute_unrescue
+
+        ... Grizzly supports message version 1.48.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.48.
+
     1.49 - Added columns_to_join to instance_get_by_uuid
     1.50 - Added object_action() and object_class_action()
     1.51 - Added the 'legacy' argument to
@@ -96,11 +106,18 @@ class ConductorAPI(nova.openstack.common.rpc.proxy.RpcProxy):
 
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '1.48',
+    }
+
     def __init__(self):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.conductor,
+                                               CONF.upgrade_levels.conductor)
         super(ConductorAPI, self).__init__(
             topic=CONF.conductor.topic,
             default_version=self.BASE_RPC_API_VERSION,
-            serializer=objects_base.NovaObjectSerializer())
+            serializer=objects_base.NovaObjectSerializer(),
+            version_cap=version_cap)
 
     def instance_update(self, context, instance_uuid, updates,
                         service=None):
@@ -119,10 +136,16 @@ class ConductorAPI(nova.openstack.common.rpc.proxy.RpcProxy):
 
     def instance_get_by_uuid(self, context, instance_uuid,
                              columns_to_join=None):
-        msg = self.make_msg('instance_get_by_uuid',
-                            instance_uuid=instance_uuid,
-                            columns_to_join=columns_to_join)
-        return self.call(context, msg, version='1.49')
+        if self.can_send_version('1.49'):
+            version = '1.49'
+            msg = self.make_msg('instance_get_by_uuid',
+                                instance_uuid=instance_uuid,
+                                columns_to_join=columns_to_join)
+        else:
+            version = '1.2'
+            msg = self.make_msg('instance_get_by_uuid',
+                                instance_uuid=instance_uuid)
+        return self.call(context, msg, version=version)
 
     def migration_get(self, context, migration_id):
         msg = self.make_msg('migration_get', migration_id=migration_id)
diff --git a/nova/console/rpcapi.py b/nova/console/rpcapi.py
index 86debae32dc4..7a78b52c2263 100644
--- a/nova/console/rpcapi.py
+++ b/nova/console/rpcapi.py
@@ -31,6 +31,11 @@ rpcapi_opts = [
 CONF = cfg.CONF
 CONF.register_opts(rpcapi_opts)
 
+rpcapi_cap_opt = cfg.StrOpt('console',
+        default=None,
+        help='Set a version cap for messages sent to console services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class ConsoleAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     '''Client side of the console rpc API.
@@ -39,6 +44,10 @@ class ConsoleAPI(nova.openstack.common.rpc.proxy.RpcProxy):
 
         1.0 - Initial version.
         1.1 - Added get_backdoor_port()
+
+        ... Grizzly supports message version 1.1.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.1.
     '''
 
     #
@@ -51,11 +60,18 @@ class ConsoleAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '1.1',
+    }
+
     def __init__(self, topic=None):
         topic = topic if topic else CONF.console_topic
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.console,
+                                               CONF.upgrade_levels.console)
         super(ConsoleAPI, self).__init__(
                 topic=topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
 
     def add_console(self, ctxt, instance_id):
         self.cast(ctxt, self.make_msg('add_console', instance_id=instance_id))
diff --git a/nova/consoleauth/rpcapi.py b/nova/consoleauth/rpcapi.py
index 62aeab8dafbd..ffc1a3de4e14 100644
--- a/nova/consoleauth/rpcapi.py
+++ b/nova/consoleauth/rpcapi.py
@@ -24,6 +24,11 @@ import nova.openstack.common.rpc.proxy
 
 CONF = cfg.CONF
 
+rpcapi_cap_opt = cfg.StrOpt('consoleauth',
+        default=None,
+        help='Set a version cap for messages sent to consoleauth services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class ConsoleAuthAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     '''Client side of the consoleauth rpc API.
@@ -34,6 +39,10 @@ class ConsoleAuthAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         1.1 - Added get_backdoor_port()
         1.2 - Added instance_uuid to authorize_console, and
               delete_tokens_for_instance
+
+        ... Grizzly supports message version 1.2.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.2.
     '''
 
     #
@@ -46,10 +55,17 @@ class ConsoleAuthAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '1.2',
+    }
+
     def __init__(self):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.consoleauth,
+                                               CONF.upgrade_levels.consoleauth)
         super(ConsoleAuthAPI, self).__init__(
                 topic=CONF.consoleauth_topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
 
     def authorize_console(self, ctxt, token, console_type, host, port,
                           internal_access_path, instance_uuid=None):
diff --git a/nova/network/rpcapi.py b/nova/network/rpcapi.py
index c335c9cb455f..1fa5610ca0f1 100644
--- a/nova/network/rpcapi.py
+++ b/nova/network/rpcapi.py
@@ -37,6 +37,11 @@ rpcapi_opts = [
 CONF = cfg.CONF
 CONF.register_opts(rpcapi_opts)
 
+rpcapi_cap_opt = cfg.StrOpt('network',
+        default=None,
+        help='Set a version cap for messages sent to network services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class NetworkAPI(rpc_proxy.RpcProxy):
     '''Client side of the network rpc API.
@@ -54,6 +59,10 @@ class NetworkAPI(rpc_proxy.RpcProxy):
         1.8 - Adds macs to allocate_for_instance
         1.9 - Adds rxtx_factor to [add|remove]_fixed_ip, removes instance_uuid
               from allocate_for_instance and instance_get_nw_info
+
+        ... Grizzly supports message version 1.9.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 1.9.
     '''
 
     #
@@ -66,11 +75,18 @@ class NetworkAPI(rpc_proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '1.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '1.9',
+    }
+
     def __init__(self, topic=None):
         topic = topic if topic else CONF.network_topic
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.network,
+                                               CONF.upgrade_levels.network)
         super(NetworkAPI, self).__init__(
                 topic=topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
 
     def get_all_networks(self, ctxt):
         return self.call(ctxt, self.make_msg('get_all_networks'))
diff --git a/nova/scheduler/rpcapi.py b/nova/scheduler/rpcapi.py
index 2cfd5688fbf8..369363bb4bde 100644
--- a/nova/scheduler/rpcapi.py
+++ b/nova/scheduler/rpcapi.py
@@ -32,6 +32,11 @@ rpcapi_opts = [
 CONF = cfg.CONF
 CONF.register_opts(rpcapi_opts)
 
+rpcapi_cap_opt = cfg.StrOpt('scheduler',
+        default=None,
+        help='Set a version cap for messages sent to scheduler services')
+CONF.register_opt(rpcapi_cap_opt, 'upgrade_levels')
+
 
 class SchedulerAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     '''Client side of the scheduler rpc API.
@@ -58,6 +63,10 @@ class SchedulerAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 - accepts a list of capabilities
         2.5 - Add get_backdoor_port()
         2.6 - Add select_hosts()
+
+        ... Grizzly supports message version 2.6.  So, any changes to existing
+        methods in 2.x after that point should be done such that they can
+        handle the version_cap being set to 2.6.
     '''
 
     #
@@ -70,9 +79,16 @@ class SchedulerAPI(nova.openstack.common.rpc.proxy.RpcProxy):
     #
     BASE_RPC_API_VERSION = '2.0'
 
+    VERSION_ALIASES = {
+        'grizzly': '2.6',
+    }
+
     def __init__(self):
+        version_cap = self.VERSION_ALIASES.get(CONF.upgrade_levels.scheduler,
+                                               CONF.upgrade_levels.scheduler)
         super(SchedulerAPI, self).__init__(topic=CONF.scheduler_topic,
-                default_version=self.BASE_RPC_API_VERSION)
+                default_version=self.BASE_RPC_API_VERSION,
+                version_cap=version_cap)
 
     def run_instance(self, ctxt, request_spec, admin_password,
             injected_files, requested_networks, is_first_time,