Not creating HA router when not enough l3 agents

Currently a HA router can be successfully created even when
there is not enough active l3 agent. Current code only checks
existing l3 agents but does not check if the agent is already
down.

This patch fixes this problem by checking only active l3 agents
when getting the number of agents for scheduling HA router.

Closes-Bug: 1420117

Change-Id: I6c1d108db1a7c93b61c0dd0b1ffee319a411b17a

diff --git a/neutron/db/l3_hamode_db.py b/neutron/db/l3_hamode_db.py
index 74884d2dfa15edebabd47704ba2fd057ce74f6ea..7d52eb1d18d4a689eb07549cf8e74597ba56fde7 100644 (file)
--- a/neutron/db/l3_hamode_db.py
+++ b/neutron/db/l3_hamode_db.py
@@ -262,13 +262,13 @@ class L3_HA_NAT_db_mixin(l3_dvr_db.L3_NAT_with_dvr_db_mixin):
         """
 
         min_agents = cfg.CONF.min_l3_agents_per_router
-        num_agents = len(self.get_l3_agents(context,
+        num_agents = len(self.get_l3_agents(context, active=True,
             filters={'agent_modes': [constants.L3_AGENT_MODE_LEGACY,
                                      constants.L3_AGENT_MODE_DVR_SNAT]}))
         max_agents = cfg.CONF.max_l3_agents_per_router
         if max_agents:
             if max_agents > num_agents:
-                LOG.info(_LI("Number of available agents lower than "
+                LOG.info(_LI("Number of active agents lower than "
                              "max_l3_agents_per_router. L3 agents "
                              "available: %s"), num_agents)
             else:

diff --git a/neutron/tests/unit/db/test_l3_hamode_db.py b/neutron/tests/unit/db/test_l3_hamode_db.py
index e13991aa0e0245d70a7c3c30733cf4c810301ce6..bd8f9e9cd443c9e5cda47eca47b9b89eea30e44a 100644 (file)
--- a/neutron/tests/unit/db/test_l3_hamode_db.py
+++ b/neutron/tests/unit/db/test_l3_hamode_db.py
@@ -12,8 +12,10 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import datetime
 import mock
 from oslo_config import cfg
+from oslo_utils import timeutils
 
 from neutron.api.v2 import attributes
 from neutron.common import constants
@@ -52,22 +54,28 @@ class L3HATestFramework(testlib_api.SqlTestCase):
         cfg.CONF.set_override('allow_overlapping_ips', True)
 
         self.plugin = FakeL3PluginWithAgents()
-        self._register_agents()
+        self.agent1 = self._register_agent('legacy', 'l3host')
+        self.agent2 = self._register_agent('dvr_snat', 'l3host_2')
 
-    def _register_agents(self):
+    def _register_agent(self, agent_mode, host):
         agent_status = {
             'agent_type': constants.AGENT_TYPE_L3,
             'binary': 'neutron-l3-agent',
-            'host': 'l3host',
+            'host': host,
             'topic': 'N/A',
-            'configurations': {'agent_mode': 'legacy'}
+            'configurations': {'agent_mode': agent_mode}
         }
 
         self.plugin.create_or_update_agent(self.admin_ctx, agent_status)
-        agent_status['host'] = 'l3host_2'
-        agent_status['configurations'] = {'agent_mode': 'dvr_snat'}
-        self.plugin.create_or_update_agent(self.admin_ctx, agent_status)
-        self.agent1, self.agent2 = self.plugin.get_agents(self.admin_ctx)
+        return self.plugin.get_agents(
+            self.admin_ctx, filters={'host': [host]})[0]
+
+    def _bring_down_agent(self, agent_id):
+        update = {
+            'agent': {
+                'heartbeat_timestamp':
+                timeutils.utcnow() - datetime.timedelta(hours=1)}}
+        self.plugin.update_agent(self.admin_ctx, agent_id, update)
 
     def _create_router(self, ha=True, tenant_id='tenant1', distributed=None,
                        ctx=None):
@@ -478,6 +486,14 @@ class L3HATestCase(L3HATestFramework):
             self.admin_ctx)
         self.assertEqual(2, num_ha_candidates)
 
+    def test_get_number_of_agents_for_scheduling_not_enough_agents(self):
+        cfg.CONF.set_override('min_l3_agents_per_router', 3)
+        agent_to_bring_down = self._register_agent('legacy', 'l3host_3')
+        self._bring_down_agent(agent_to_bring_down['id'])
+        self.assertRaises(l3_ext_ha_mode.HANotEnoughAvailableAgents,
+                          self.plugin.get_number_of_agents_for_scheduling,
+                          self.admin_ctx)
+
 
 class L3HAModeDbTestCase(L3HATestFramework):
 

diff --git a/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py b/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
index 09e3f708021ed7b7cf9f4b573a3d41f061d86588..f7ee3d766fe85ba887b03409170b1ebedb5259a8 100644 (file)
--- a/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
+++ b/neutron/tests/unit/scheduler/test_l3_agent_scheduler.py
@@ -1641,10 +1641,10 @@ class L3HAChanceSchedulerTestCase(L3HATestCaseMixin):
             admin_state_up=True)
         self.assertEqual(2, len(agents))
 
+        r2 = self._create_ha_router()
         self._set_l3_agent_admin_state(self.adminContext,
                                        self.agent_id2, False)
 
-        r2 = self._create_ha_router()
         self.plugin.schedule_router(self.adminContext, r2['id'])
         agents = self.plugin.get_l3_agents_hosting_routers(
             self.adminContext, [r2['id']],