From: Kevin Benton <blak111@gmail.com>
Date: Wed, 16 Dec 2015 06:49:50 +0000 (-0800)
Subject: Use a joined relationship for AZ info on routers
X-Git-Url: https://review.fuel-infra.org/gitweb?a=commitdiff_plain;h=0b2fa9540655b27e5dc079dade29f232cadc0531;p=openstack-build%2Fneutron-build.git

Use a joined relationship for AZ info on routers

This patch adds a joined relationship from the routers
to the agent table to prevent excessive DB lookups of the
agent availability zones during router listings.

This fix is the same as the one for networks here:
I908ceb1a68e0eed7c304e3ff82279ad6fa406167

A follow-up patch will add an AZ table so this doesn't
have to join directly to the agents table.

Change-Id: I808f8ff0c581478b2ea1144e297d83af599a32f2
Closes-Bug: #1526644
---

diff --git a/neutron/db/availability_zone/router.py b/neutron/db/availability_zone/router.py
index ccb7244f4..1f3aad493 100644
--- a/neutron/db/availability_zone/router.py
+++ b/neutron/db/availability_zone/router.py
@@ -29,7 +29,7 @@ class RouterAvailabilityZoneMixin(l3_attrs_db.ExtraAttributesMixin):
         router_res[az_ext.AZ_HINTS] = az_ext.convert_az_string_to_list(
             router_res[az_ext.AZ_HINTS])
         router_res['availability_zones'] = (
-            self.get_router_availability_zones(router_db['id']))
+            self.get_router_availability_zones(router_db))
 
     def _process_extra_attr_router_create(
         self, context, router_db, router_req):
diff --git a/neutron/db/l3_agentschedulers_db.py b/neutron/db/l3_agentschedulers_db.py
index b61de7b75..ff0010c8b 100644
--- a/neutron/db/l3_agentschedulers_db.py
+++ b/neutron/db/l3_agentschedulers_db.py
@@ -31,7 +31,6 @@ from neutron.common import utils as n_utils
 from neutron import context as n_ctx
 from neutron.db import agents_db
 from neutron.db import agentschedulers_db
-from neutron.db import api as db_api
 from neutron.db import l3_attrs_db
 from neutron.db import model_base
 from neutron.extensions import l3agentscheduler
@@ -563,12 +562,5 @@ class AZL3AgentSchedulerDbMixin(L3AgentSchedulerDbMixin,
                                 router_az.RouterAvailabilityZonePluginBase):
     """Mixin class to add availability_zone supported l3 agent scheduler."""
 
-    def get_router_availability_zones(self, router_id):
-        session = db_api.get_session()
-        with session.begin():
-            query = session.query(agents_db.Agent.availability_zone)
-            query = query.join(RouterL3AgentBinding)
-            query = query.filter(
-                RouterL3AgentBinding.router_id == router_id)
-            query = query.group_by(agents_db.Agent.availability_zone)
-            return [item[0] for item in query]
+    def get_router_availability_zones(self, router):
+        return list({agent.availability_zone for agent in router.l3_agents})
diff --git a/neutron/db/l3_db.py b/neutron/db/l3_db.py
index d27a62dc5..4c9009987 100644
--- a/neutron/db/l3_db.py
+++ b/neutron/db/l3_db.py
@@ -91,6 +91,8 @@ class Router(model_base.HasStandardAttributes, model_base.BASEV2,
         RouterPort,
         backref='router',
         lazy='dynamic')
+    l3_agents = orm.relationship('Agent', lazy='joined', viewonly=True,
+                                 secondary='routerl3agentbindings')
 
 
 class FloatingIP(model_base.HasStandardAttributes, model_base.BASEV2,
diff --git a/neutron/extensions/router_availability_zone.py b/neutron/extensions/router_availability_zone.py
index f7d2d92bc..3e09bb302 100644
--- a/neutron/extensions/router_availability_zone.py
+++ b/neutron/extensions/router_availability_zone.py
@@ -64,5 +64,5 @@ class Router_availability_zone(extensions.ExtensionDescriptor):
 class RouterAvailabilityZonePluginBase(object):
 
     @abc.abstractmethod
-    def get_router_availability_zones(self, router_id):
+    def get_router_availability_zones(self, router):
         """Return availability zones which a router belongs to."""