openstack/neutron
Code Issues Proposed changes

Skip rescheduling networks if no DHCP agents available

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This eliminates the problem of unscheduled networks in case
of communication failure between agents and servers which
can occur if messaging queue service fails.

Change-Id: Ied4fa301fc3d475bee25c47f3a01c2381ae9a01e
Closes-Bug: #1461714
This commit is contained in:
Eugene Nikanorov 2015-06-05 01:46:22 +04:00
parent 1ab4fc7319
commit 1318437a0c
2 changed files with 22 additions and 3 deletions
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11
neutron/db/agentschedulers_db.py
View File

@ -271,7 +271,16 @@ class DhcpAgentSchedulerDbMixin(dhcpagentscheduler
dhcp_notifier = self.agent_notifiers.get(constants.AGENT_TYPE_DHCP)
try:
for binding in self._filter_bindings(context, down_bindings):
dead_bindings = [b for b in
self._filter_bindings(context, down_bindings)]
dead_agents = set([b.dhcp_agent_id for b in dead_bindings])
agents = self.get_agents_db(
context, {'agent_type': [constants.AGENT_TYPE_DHCP]})
if len(agents) == len(dead_agents):
LOG.warn(_LW("No DHCP agents available, "
"skipping rescheduling"))
return
for binding in dead_bindings:
LOG.warn(_LW("Removing network %(network)s from agent "
"%(agent)s because the agent did not report "
"to the server in the last %(dead_time)s "

14
neutron/tests/unit/scheduler/test_dhcp_agent_scheduler.py
View File

@ -21,6 +21,7 @@ import testscenarios
from neutron.common import constants
from neutron import context
from neutron.db import agentschedulers_db as sched_db
from neutron.db import common_db_mixin
from neutron.db import models_v2
from neutron.extensions import dhcpagentscheduler
from neutron.scheduler import dhcp_agent_scheduler
@ -177,7 +178,8 @@ class TestAutoScheduleNetworks(TestDhcpSchedulerBaseTestCase):
class TestNetworksFailover(TestDhcpSchedulerBaseTestCase,
sched_db.DhcpAgentSchedulerDbMixin):
sched_db.DhcpAgentSchedulerDbMixin,
common_db_mixin.CommonDbMixin):
def test_reschedule_network_from_down_agent(self):
agents = self._create_and_set_agents_down(['host-a', 'host-b'], 1)
self._test_schedule_bind_network([agents[0]], self.network_id)
@ -201,7 +203,7 @@ class TestNetworksFailover(TestDhcpSchedulerBaseTestCase,
mock.ANY, self.network_id, agents[1].host)
def _test_failed_rescheduling(self, rn_side_effect=None):
agents = self._create_and_set_agents_down(['host-a'], 1)
agents = self._create_and_set_agents_down(['host-a', 'host-b'], 1)
self._test_schedule_bind_network([agents[0]], self.network_id)
with mock.patch.object(self,
'remove_network_from_dhcp_agent',
@ -257,6 +259,14 @@ class TestNetworksFailover(TestDhcpSchedulerBaseTestCase,
# just make sure that no exception is raised
self.remove_networks_from_down_agents()
def test_reschedule_doesnt_occur_if_no_agents(self):
agents = self._create_and_set_agents_down(['host-a'], 1)
self._test_schedule_bind_network([agents[0]], self.network_id)
with mock.patch.object(
self, 'remove_network_from_dhcp_agent') as rn:
self.remove_networks_from_down_agents()
self.assertFalse(rn.called)
class DHCPAgentWeightSchedulerTestCase(TestDhcpSchedulerBaseTestCase):
"""Unit test scenarios for WeightScheduler.schedule."""