Improve test coverage of dhcp agent scheduling

This patch adds few unit test cases and functional test cases
for schedule() and auto_schedule_networks() of DHCP agent
ChanceScheduler.

Change-Id: I6ed7c48bcf5fc43d805c7898c7d6f019b6792e18
Closes-bug: #1331516
This commit is contained in:
Numan Siddique 2014-09-11 20:25:20 +05:30
parent d145fee017
commit 690f879778
3 changed files with 458 additions and 43 deletions

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@ -0,0 +1,347 @@
# Copyright (c) 2015 Red Hat, Inc.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import six
import testscenarios
from neutron import context
from neutron.db import agents_db
from neutron.db import agentschedulers_db
from neutron.db import common_db_mixin
from neutron.scheduler import dhcp_agent_scheduler
from neutron.tests.unit import test_dhcp_scheduler as test_dhcp_sch
# Required to generate tests from scenarios. Not compatible with nose.
load_tests = testscenarios.load_tests_apply_scenarios
class TestScheduleNetwork(test_dhcp_sch.TestDhcpSchedulerBaseTestCase,
agentschedulers_db.DhcpAgentSchedulerDbMixin,
agents_db.AgentDbMixin,
common_db_mixin.CommonDbMixin):
"""Test various scenarios for ChanceScheduler.schedule.
agent_count
Number of dhcp agents (also number of hosts).
max_agents_per_network
Maximum DHCP Agents that can be scheduled for a network.
scheduled_agent_count
Number of agents the network has previously scheduled
down_agent_count
Number of dhcp agents which are down
expected_scheduled_agent_count
Number of scheduled agents the schedule() should return
or 'None' if the schedule() cannot schedule the network.
"""
scenarios = [
('No agents scheduled if no agents are present',
dict(agent_count=0,
max_agents_per_network=1,
scheduled_agent_count=0,
down_agent_count=0,
expected_scheduled_agent_count=None)),
('No agents scheduled if network already hosted and'
' max_agents_per_network reached',
dict(agent_count=1,
max_agents_per_network=1,
scheduled_agent_count=1,
down_agent_count=0,
expected_scheduled_agent_count=None)),
('No agents scheduled if all agents are down',
dict(agent_count=2,
max_agents_per_network=1,
scheduled_agent_count=0,
down_agent_count=2,
expected_scheduled_agent_count=None)),
('Agent scheduled to the network if network is not yet hosted',
dict(agent_count=1,
max_agents_per_network=1,
scheduled_agent_count=0,
down_agent_count=0,
expected_scheduled_agent_count=1)),
('Additional Agents scheduled to the network if max_agents_per_network'
' is not yet reached',
dict(agent_count=3,
max_agents_per_network=3,
scheduled_agent_count=1,
down_agent_count=0,
expected_scheduled_agent_count=2)),
('No agent scheduled if agent is dead',
dict(agent_count=3,
max_agents_per_network=3,
scheduled_agent_count=1,
down_agent_count=1,
expected_scheduled_agent_count=1)),
]
def test_schedule_network(self):
self.config(dhcp_agents_per_network=self.max_agents_per_network)
scheduler = dhcp_agent_scheduler.ChanceScheduler()
# create dhcp agents
hosts = ['host-%s' % i for i in range(self.agent_count)]
dhcp_agents = self._create_and_set_agents_down(
hosts, down_agent_count=self.down_agent_count)
active_agents = dhcp_agents[self.down_agent_count:]
# schedule some agents before calling schedule
if self.scheduled_agent_count:
# schedule the network
schedule_agents = active_agents[:self.scheduled_agent_count]
scheduler._schedule_bind_network(self.ctx, schedule_agents,
self.network_id)
actual_scheduled_agents = scheduler.schedule(self, self.ctx,
self.network)
if self.expected_scheduled_agent_count:
self.assertEqual(self.expected_scheduled_agent_count,
len(actual_scheduled_agents))
hosted_agents = self.list_dhcp_agents_hosting_network(
self.ctx, self.network_id)
self.assertEqual(self.scheduled_agent_count +
len(actual_scheduled_agents),
len(hosted_agents['agents']))
else:
self.assertIsNone(actual_scheduled_agents)
class TestAutoSchedule(test_dhcp_sch.TestDhcpSchedulerBaseTestCase,
agentschedulers_db.DhcpAgentSchedulerDbMixin,
agents_db.AgentDbMixin,
common_db_mixin.CommonDbMixin):
"""Test various scenarios for ChanceScheduler.auto_schedule_networks.
Below is the brief description of the scenario variables
--------------------------------------------------------
agent_count
number of DHCP agents (also number of hosts).
max_agents_per_network
Maximum DHCP Agents that can be scheduled for a network.
network_count
Number of networks.
networks_with_dhcp_disabled
List of networks with dhcp disabled
hosted_networks
A mapping of agent id to the ids of the networks that they
should be initially hosting.
expected_auto_schedule_return_value
Expected return value of 'auto_schedule_networks'.
expected_hosted_networks
This stores the expected networks that should have been scheduled
(or that could have already been scheduled) for each agent
after the 'auto_schedule_networks' function is called.
"""
scenarios = [
('Agent scheduled to the network if network is not yet hosted',
dict(agent_count=1,
max_agents_per_network=1,
network_count=1,
networks_with_dhcp_disabled=[],
hosted_networks={},
expected_auto_schedule_return_value=True,
expected_hosted_networks={'agent-0': ['network-0']})),
('No agent scheduled if no networks are present',
dict(agent_count=1,
max_agents_per_network=1,
network_count=0,
networks_with_dhcp_disabled=[],
hosted_networks={},
expected_auto_schedule_return_value=False,
expected_hosted_networks={'agent-0': []})),
('Agents scheduled to the networks if networks are not yet hosted',
dict(agent_count=2,
max_agents_per_network=3,
network_count=2,
networks_with_dhcp_disabled=[],
hosted_networks={},
expected_auto_schedule_return_value=True,
expected_hosted_networks={'agent-0': ['network-0',
'network-1'],
'agent-1': ['network-0',
'network-1']})),
('No new agents scheduled if networks are already hosted',
dict(agent_count=2,
max_agents_per_network=3,
network_count=2,
networks_with_dhcp_disabled=[],
hosted_networks={'agent-0': ['network-0', 'network-1'],
'agent-1': ['network-0', 'network-1']},
expected_auto_schedule_return_value=True,
expected_hosted_networks={'agent-0': ['network-0',
'network-1'],
'agent-1': ['network-0',
'network-1']})),
('Additional agents scheduled to the networks if'
' max_agents_per_network is not yet reached',
dict(agent_count=4,
max_agents_per_network=3,
network_count=4,
networks_with_dhcp_disabled=[],
hosted_networks={'agent-0': ['network-0', 'network-1'],
'agent-1': ['network-0'],
'agent-2': ['network-2'],
'agent-3': ['network-0', 'network-2']},
expected_auto_schedule_return_value=True,
expected_hosted_networks={'agent-0': ['network-0',
'network-1',
'network-2',
'network-3'],
'agent-1': ['network-0',
'network-1',
'network-2',
'network-3'],
'agent-2': ['network-1',
'network-2',
'network-3'],
'agent-3': ['network-0',
'network-1',
'network-2',
'network-3']})),
('No agents scheduled if networks already hosted and'
' max_agents_per_network reached',
dict(agent_count=4,
max_agents_per_network=1,
network_count=4,
networks_with_dhcp_disabled=[],
hosted_networks={'agent-0': ['network-0'],
'agent-1': ['network-2'],
'agent-2': ['network-1'],
'agent-3': ['network-3']},
expected_auto_schedule_return_value=True,
expected_hosted_networks={'agent-0': ['network-0'],
'agent-1': ['network-2'],
'agent-2': ['network-1'],
'agent-3': ['network-3']})),
('No agents scheduled to the network with dhcp disabled',
dict(agent_count=2,
max_agents_per_network=3,
network_count=2,
networks_with_dhcp_disabled=['network-1'],
hosted_networks={},
expected_auto_schedule_return_value=True,
expected_hosted_networks={'agent-0': ['network-0'],
'agent-1': ['network-0']})),
('No agents scheduled if all networks have dhcp disabled',
dict(agent_count=2,
max_agents_per_network=3,
network_count=2,
networks_with_dhcp_disabled=['network-0', 'network-1'],
hosted_networks={},
expected_auto_schedule_return_value=False,
expected_hosted_networks={'agent-0': [],
'agent-1': []})),
]
def _strip_host_index(self, name):
"""Strips the host index.
Eg. if name = '2-agent-3', then 'agent-3' is returned.
"""
return name[name.find('-') + 1:]
def _extract_index(self, name):
"""Extracts the index number and returns.
Eg. if name = '2-agent-3', then 3 is returned
"""
return int(name.split('-')[-1])
def get_subnets(self, context, fields=None):
subnets = []
for net_id in self._networks:
enable_dhcp = (not self._strip_host_index(net_id) in
self.networks_with_dhcp_disabled)
subnets.append({'network_id': net_id,
'enable_dhcp': enable_dhcp})
return subnets
def _get_hosted_networks_on_dhcp_agent(self, agent_id):
query = self.ctx.session.query(
agentschedulers_db.NetworkDhcpAgentBinding.network_id)
query = query.filter(
agentschedulers_db.NetworkDhcpAgentBinding.dhcp_agent_id ==
agent_id)
return [item[0] for item in query]
def _test_auto_schedule(self, host_index):
self.config(dhcp_agents_per_network=self.max_agents_per_network)
scheduler = dhcp_agent_scheduler.ChanceScheduler()
self.ctx = context.get_admin_context()
msg = 'host_index = %s' % host_index
# create dhcp agents
hosts = ['%s-agent-%s' % (host_index, i)
for i in range(self.agent_count)]
dhcp_agents = self._create_and_set_agents_down(hosts)
# create networks
self._networks = ['%s-network-%s' % (host_index, i)
for i in range(self.network_count)]
self._save_networks(self._networks)
# pre schedule the networks to the agents defined in
# self.hosted_networks before calling auto_schedule_network
for agent, networks in six.iteritems(self.hosted_networks):
agent_index = self._extract_index(agent)
for net in networks:
net_index = self._extract_index(net)
scheduler._schedule_bind_network(self.ctx,
[dhcp_agents[agent_index]],
self._networks[net_index])
retval = scheduler.auto_schedule_networks(self, self.ctx,
hosts[host_index])
self.assertEqual(self.expected_auto_schedule_return_value, retval,
message=msg)
agent_id = dhcp_agents[host_index].id
hosted_networks = self._get_hosted_networks_on_dhcp_agent(agent_id)
hosted_net_ids = [self._strip_host_index(net)
for net in hosted_networks]
expected_hosted_networks = self.expected_hosted_networks['agent-%s' %
host_index]
for hosted_net_id in hosted_net_ids:
self.assertIn(hosted_net_id, expected_hosted_networks,
message=msg + '[%s]' % hosted_net_id)
def test_auto_schedule(self):
for i in range(self.agent_count):
self._test_auto_schedule(i)

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@ -13,9 +13,12 @@
# See the License for the specific language governing permissions and
# limitations under the License.
import mock
import datetime
import mock
from oslo.utils import timeutils
import testscenarios
from neutron.common import constants
from neutron.common import topics
@ -26,12 +29,16 @@ from neutron.db import models_v2
from neutron.scheduler import dhcp_agent_scheduler
from neutron.tests.unit import testlib_api
# Required to generate tests from scenarios. Not compatible with nose.
load_tests = testscenarios.load_tests_apply_scenarios
class DhcpSchedulerTestCase(testlib_api.SqlTestCase):
class TestDhcpSchedulerBaseTestCase(testlib_api.SqlTestCase):
def setUp(self):
super(DhcpSchedulerTestCase, self).setUp()
super(TestDhcpSchedulerBaseTestCase, self).setUp()
self.ctx = context.get_admin_context()
self.network = {'id': 'foo_network_id'}
self.network_id = 'foo_network_id'
self._save_networks([self.network_id])
@ -54,6 +61,16 @@ class DhcpSchedulerTestCase(testlib_api.SqlTestCase):
with self.ctx.session.begin(subtransactions=True):
self.ctx.session.add(agent)
def _create_and_set_agents_down(self, hosts, down_agent_count=0):
dhcp_agents = self._get_agents(hosts)
# bring down the specified agents
for agent in dhcp_agents[:down_agent_count]:
old_time = agent['heartbeat_timestamp']
hour_old = old_time - datetime.timedelta(hours=1)
agent['heartbeat_timestamp'] = hour_old
self._save_agents(dhcp_agents)
return dhcp_agents
def _save_networks(self, networks):
for network_id in networks:
with self.ctx.session.begin(subtransactions=True):
@ -62,64 +79,115 @@ class DhcpSchedulerTestCase(testlib_api.SqlTestCase):
def _test_schedule_bind_network(self, agents, network_id):
scheduler = dhcp_agent_scheduler.ChanceScheduler()
scheduler._schedule_bind_network(self.ctx, agents, network_id)
results = (
self.ctx.session.query(agentschedulers_db.NetworkDhcpAgentBinding).
filter_by(network_id=network_id).all())
results = self.ctx.session.query(
agentschedulers_db.NetworkDhcpAgentBinding).filter_by(
network_id=network_id).all()
self.assertEqual(len(agents), len(results))
for result in results:
self.assertEqual(network_id, result.network_id)
class TestDhcpScheduler(TestDhcpSchedulerBaseTestCase):
def test_schedule_bind_network_single_agent(self):
agents = self._get_agents(['host-a'])
self._save_agents(agents)
agents = self._create_and_set_agents_down(['host-a'])
self._test_schedule_bind_network(agents, self.network_id)
def test_schedule_bind_network_multi_agents(self):
agents = self._get_agents(['host-a', 'host-b'])
self._save_agents(agents)
agents = self._create_and_set_agents_down(['host-a', 'host-b'])
self._test_schedule_bind_network(agents, self.network_id)
def test_schedule_bind_network_multi_agent_fail_one(self):
agents = self._get_agents(['host-a'])
self._save_agents(agents)
agents = self._create_and_set_agents_down(['host-a'])
self._test_schedule_bind_network(agents, self.network_id)
with mock.patch.object(dhcp_agent_scheduler.LOG, 'info') as fake_log:
self._test_schedule_bind_network(agents, self.network_id)
self.assertEqual(1, fake_log.call_count)
def test_auto_schedule_networks_no_networks(self):
plugin = mock.MagicMock()
plugin.get_networks.return_value = []
scheduler = dhcp_agent_scheduler.ChanceScheduler()
self.assertFalse(scheduler.auto_schedule_networks(plugin,
self.ctx, "host-a"))
def test_auto_schedule_networks(self):
plugin = mock.MagicMock()
plugin.get_subnets.return_value = [{"network_id": self.network_id,
"enable_dhcp": True}]
agents = self._get_agents(['host-a'])
self._save_agents(agents)
scheduler = dhcp_agent_scheduler.ChanceScheduler()
class TestAutoScheduleNetworks(TestDhcpSchedulerBaseTestCase):
"""Unit test scenarios for ChanceScheduler.auto_schedule_networks.
self.assertTrue(scheduler.auto_schedule_networks(plugin,
self.ctx, "host-a"))
results = (
self.ctx.session.query(agentschedulers_db.NetworkDhcpAgentBinding)
.all())
self.assertEqual(1, len(results))
network_present
Network is present or not
def test_auto_schedule_networks_network_already_scheduled(self):
enable_dhcp
Dhcp is enabled or disabled in the subnet of the network
scheduled_already
Network is already scheduled to the agent or not
agent_down
Dhcp agent is down or alive
valid_host
If true, then an valid host is passed to schedule the network,
else an invalid host is passed.
"""
scenarios = [
('Network present',
dict(network_present=True,
enable_dhcp=True,
scheduled_already=False,
agent_down=False,
valid_host=True)),
('No network',
dict(network_present=False,
enable_dhcp=False,
scheduled_already=False,
agent_down=False,
valid_host=True)),
('Network already scheduled',
dict(network_present=True,
enable_dhcp=True,
scheduled_already=True,
agent_down=False,
valid_host=True)),
('Agent down',
dict(network_present=True,
enable_dhcp=True,
scheduled_already=False,
agent_down=False,
valid_host=True)),
('dhcp disabled',
dict(network_present=True,
enable_dhcp=False,
scheduled_already=False,
agent_down=False,
valid_host=False)),
('Invalid host',
dict(network_present=True,
enable_dhcp=True,
scheduled_already=False,
agent_down=False,
valid_host=False)),
]
def test_auto_schedule_network(self):
plugin = mock.MagicMock()
plugin.get_subnets.return_value = [{"network_id": self.network_id,
"enable_dhcp": True}]
agents = self._get_agents(['host-a'])
self._save_agents(agents)
plugin.get_subnets.return_value = (
[{"network_id": self.network_id, "enable_dhcp": self.enable_dhcp}]
if self.network_present else [])
scheduler = dhcp_agent_scheduler.ChanceScheduler()
self._test_schedule_bind_network(agents, self.network_id)
self.assertTrue(scheduler.auto_schedule_networks(plugin,
self.ctx, "host-a"))
results = (
self.ctx.session.query(agentschedulers_db.NetworkDhcpAgentBinding)
.all())
self.assertEqual(1, len(results))
if self.network_present:
down_agent_count = 1 if self.agent_down else 0
agents = self._create_and_set_agents_down(
['host-a'], down_agent_count=down_agent_count)
if self.scheduled_already:
self._test_schedule_bind_network(agents, self.network_id)
expected_result = (self.network_present and self.enable_dhcp)
expected_hosted_agents = (1 if expected_result and
self.valid_host else 0)
host = "host-a" if self.valid_host else "host-b"
observed_ret_value = scheduler.auto_schedule_networks(
plugin, self.ctx, host)
self.assertEqual(expected_result, observed_ret_value)
hosted_agents = self.ctx.session.query(
agentschedulers_db.NetworkDhcpAgentBinding).all()
self.assertEqual(expected_hosted_agents, len(hosted_agents))