openstack
/
neutron
Code Issues Proposed changes

Split the FIP Namespace delete in L3 agent for DVR 

Right now we are seeing a race condition in the l3 agent
for DVR routers when a floatingip is deleted and created.

The agent tries to delete the floatingip namespace and
while it tries to delete there is another call to add a
namespace. There is a timing window in between these two
calls where sometimes the call to create a namespace succeeds
but, when tried to execute any commands in the namespace
it fails, since the namespace was deleted concurrently.

Since the fip namespace is associated with an external net
and each node has only one fip namespace for an external net,
we would like to only delete the fip namespace when the
external net is deleted.

The first step is to split the delete functionality into two.
The call to fip_ns.cleanup will only remove the dependency that
the fipnamespace has with the router namespace such as fpr and
rfp veth pairs.

The call to fip_ns.delete will actually delete the
the fip namespace and the fg device.

Partial-Bug: #1501873
Change-Id: Ic94625d5a968f554af70c274b2b2c20ab64e2487
This commit is contained in:
Swaminathan Vasudevan 2015-09-30 11:15:52 -07:00 committed by Carl Baldwin
parent d57c546f1f
commit c874f6dada
3 changed files with 12 additions and 56 deletions
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24
neutron/agent/l3/dvr_local_router.py
View File

@ -136,26 +136,10 @@ class DvrLocalRouter(dvr_router_base.DvrRouterBase):
self.fip_ns.local_subnets.release(self.router_id)
self.rtr_fip_subnet = None
ns_ip.del_veth(fip_2_rtr_name)
is_last = self.fip_ns.unsubscribe(self.router_id)
if is_last:
# TODO(Carl) I can't help but think that another router could
# come in and want to start using this namespace while this is
# destroying it. The two could end up conflicting on
# creating/destroying interfaces and such. I think I'd like a
# semaphore to sync creation/deletion of this namespace.
# NOTE (Swami): Since we are deleting the namespace here we
# should be able to delete the floatingip agent gateway port
# for the provided external net since we don't need it anymore.
if self.fip_ns.agent_gateway_port:
LOG.debug('Removed last floatingip, so requesting the '
'server to delete Floatingip Agent Gateway port:'
'%s', self.fip_ns.agent_gateway_port)
self.agent.plugin_rpc.delete_agent_gateway_port(
self.agent.context,
self.fip_ns.agent_gateway_port['network_id'])
self.fip_ns.delete()
self.fip_ns = None
self.fip_ns.unsubscribe(self.router_id)
# NOTE (Swami): The fg interface and the namespace will be deleted
# when the external gateway port is removed. This will be
# initiated from the server through an RPC call.
def add_floating_ip(self, fip, interface_name, device):
if not self._add_fip_addr_to_device(fip, device):

27
neutron/tests/functional/agent/test_l3_agent.py
View File

@ -1154,7 +1154,6 @@ class TestDvrRouter(L3AgentTestFramework):
router, ip_versions, snat_ns_name)
self._delete_router(self.agent, router.router_id)
self._assert_interfaces_deleted_from_ovs()
self._assert_router_does_not_exist(router)
self._assert_snat_namespace_does_not_exist(router)
@ -1362,7 +1361,7 @@ class TestDvrRouter(L3AgentTestFramework):
router1.router[l3_constants.FLOATINGIP_KEY] = []
self.manage_router(restarted_agent, router1.router)
self._assert_dvr_snat_gateway(router1)
self.assertFalse(self._namespace_exists(fip_ns))
self.assertTrue(self._namespace_exists(fip_ns))
def test_dvr_router_add_fips_on_restarted_agent(self):
self.agent.conf.agent_mode = 'dvr'
@ -1521,30 +1520,6 @@ class TestDvrRouter(L3AgentTestFramework):
self.assertFalse(sg_device)
self.assertTrue(qg_device)
def test_dvr_router_calls_delete_agent_gateway_if_last_fip(self):
"""Test to validate delete fip if it is last fip managed by agent."""
self.agent.conf.agent_mode = 'dvr_snat'
router_info = self.generate_dvr_router_info(enable_snat=True)
router1 = self.manage_router(self.agent, router_info)
floating_agent_gw_port = (
router1.router[l3_constants.FLOATINGIP_AGENT_INTF_KEY])
self.assertTrue(floating_agent_gw_port)
fip_ns = router1.fip_ns.get_name()
router1.fip_ns.agent_gw_port = floating_agent_gw_port
self.assertTrue(self._namespace_exists(router1.ns_name))
self.assertTrue(self._namespace_exists(fip_ns))
self._assert_dvr_floating_ips(router1)
self._assert_dvr_snat_gateway(router1)
router1.router[l3_constants.FLOATINGIP_KEY] = []
rpc_mock = mock.patch.object(
self.agent.plugin_rpc, 'delete_agent_gateway_port').start()
self.agent._process_updated_router(router1.router)
self.assertTrue(rpc_mock.called)
rpc_mock.assert_called_once_with(
self.agent.context,
floating_agent_gw_port[0]['network_id'])
self.assertFalse(self._namespace_exists(fip_ns))
def _mocked_dvr_ha_router(self, agent):
r_info = self.generate_dvr_router_info(enable_ha=True,
enable_snat=True,

17
neutron/tests/unit/agent/l3/test_dvr_local_router.py
View File

@ -242,16 +242,13 @@ class TestDvrRouterOperations(base.BaseTestCase):
ri.rtr_fip_subnet = lla.LinkLocalAddressPair('15.1.2.3/32')
_, fip_to_rtr = ri.rtr_fip_subnet.get_pair()
fip_ns = ri.fip_ns
with mock.patch.object(self.plugin_api,
'delete_agent_gateway_port') as del_fip_gw:
ri.floating_ip_removed_dist(fip_cidr)
self.assertTrue(del_fip_gw.called)
self.assertTrue(fip_ns.destroyed)
mIPWrapper().del_veth.assert_called_once_with(
fip_ns.get_int_device_name(router['id']))
mIPDevice().route.delete_gateway.assert_called_once_with(
str(fip_to_rtr.ip), table=16)
fip_ns.unsubscribe.assert_called_once_with(ri.router_id)
ri.floating_ip_removed_dist(fip_cidr)
self.assertTrue(fip_ns.destroyed)
mIPWrapper().del_veth.assert_called_once_with(
fip_ns.get_int_device_name(router['id']))
mIPDevice().route.delete_gateway.assert_called_once_with(
str(fip_to_rtr.ip), table=16)
fip_ns.unsubscribe.assert_called_once_with(ri.router_id)
def _test_add_floating_ip(self, ri, fip, is_failure):
ri._add_fip_addr_to_device = mock.Mock(return_value=is_failure)