Files
deb-python-cassandra-driver/tests/unit/test_policies.py
2013-05-21 10:59:51 -05:00

304 lines
13 KiB
Python

import unittest
from threading import Thread
from cassandra import ConsistencyLevel
from cassandra.policies import (RoundRobinPolicy, DCAwareRoundRobinPolicy,
SimpleConvictionPolicy, HostDistance,
ExponentialReconnectionPolicy, RetryPolicy,
WriteType, DowngradingConsistencyRetryPolicy)
from cassandra.pool import Host
class TestRoundRobinPolicy(unittest.TestCase):
def test_basic(self):
hosts = [0, 1, 2, 3]
policy = RoundRobinPolicy()
policy.populate(None, hosts)
qplan = list(policy.make_query_plan())
self.assertEqual(sorted(qplan), hosts)
def test_multiple_query_plans(self):
hosts = [0, 1, 2, 3]
policy = RoundRobinPolicy()
policy.populate(None, hosts)
for i in xrange(20):
qplan = list(policy.make_query_plan())
self.assertEqual(sorted(qplan), hosts)
def test_single_host(self):
policy = RoundRobinPolicy()
policy.populate(None, [0])
qplan = list(policy.make_query_plan())
self.assertEqual(qplan, [0])
def test_status_updates(self):
hosts = [0, 1, 2, 3]
policy = RoundRobinPolicy()
policy.populate(None, hosts)
policy.on_down(0)
policy.on_remove(1)
policy.on_up(4)
policy.on_add(5)
qplan = list(policy.make_query_plan())
self.assertEqual(sorted(qplan), [2, 3, 4, 5])
def test_thread_safety(self):
hosts = range(100)
policy = RoundRobinPolicy()
policy.populate(None, hosts)
def check_query_plan():
for i in range(100):
qplan = list(policy.make_query_plan())
self.assertEqual(sorted(qplan), hosts)
threads = [Thread(target=check_query_plan) for i in range(4)]
map(lambda t: t.start(), threads)
map(lambda t: t.join(), threads)
class TestDCAwareRoundRobinPolicy(unittest.TestCase):
def test_no_remote(self):
hosts = []
for i in range(4):
h = Host(i, SimpleConvictionPolicy)
h.set_location_info("dc1", "rack1")
hosts.append(h)
policy = DCAwareRoundRobinPolicy("dc1")
policy.populate(None, hosts)
qplan = list(policy.make_query_plan())
self.assertEqual(sorted(qplan), sorted(hosts))
def test_with_remotes(self):
hosts = [Host(i, SimpleConvictionPolicy) for i in range(4)]
for h in hosts[:2]:
h.set_location_info("dc1", "rack1")
for h in hosts[2:]:
h.set_location_info("dc2", "rack1")
policy = DCAwareRoundRobinPolicy("dc1")
policy.populate(None, hosts)
qplan = list(policy.make_query_plan())
self.assertEqual(set(qplan[:2]), set(h for h in hosts if h.datacenter == "dc1"))
self.assertEqual(set(qplan[2:]), set(h for h in hosts if h.datacenter != "dc1"))
def test_get_distance(self):
policy = DCAwareRoundRobinPolicy("dc1", used_hosts_per_remote_dc=0)
host = Host("ip1", SimpleConvictionPolicy)
host.set_location_info("dc1", "rack1")
policy.populate(None, [host])
self.assertEqual(policy.distance(host), HostDistance.LOCAL)
# used_hosts_per_remote_dc is set to 0, so ignore it
remote_host = Host("ip2", SimpleConvictionPolicy)
remote_host.set_location_info("dc2", "rack1")
self.assertEqual(policy.distance(remote_host), HostDistance.IGNORED)
# dc2 isn't registered in the policy's live_hosts dict
policy.used_hosts_per_remote_dc = 1
self.assertEqual(policy.distance(remote_host), HostDistance.IGNORED)
# make sure the policy has both dcs registered
policy.populate(None, [host, remote_host])
self.assertEqual(policy.distance(remote_host), HostDistance.REMOTE)
# since used_hosts_per_remote_dc is set to 1, only the first
# remote host in dc2 will be REMOTE, the rest are IGNORED
second_remote_host = Host("ip3", SimpleConvictionPolicy)
second_remote_host.set_location_info("dc2", "rack1")
policy.populate(None, [host, remote_host, second_remote_host])
distances = set([policy.distance(remote_host), policy.distance(second_remote_host)])
self.assertEqual(distances, set([HostDistance.REMOTE, HostDistance.IGNORED]))
def test_status_updates(self):
hosts = [Host(i, SimpleConvictionPolicy) for i in range(4)]
for h in hosts[:2]:
h.set_location_info("dc1", "rack1")
for h in hosts[2:]:
h.set_location_info("dc2", "rack1")
policy = DCAwareRoundRobinPolicy("dc1", used_hosts_per_remote_dc=1)
policy.populate(None, hosts)
policy.on_down(hosts[0])
policy.on_remove(hosts[2])
new_local_host = Host(4, SimpleConvictionPolicy)
new_local_host.set_location_info("dc1", "rack1")
policy.on_up(new_local_host)
new_remote_host = Host(5, SimpleConvictionPolicy)
new_remote_host.set_location_info("dc9000", "rack1")
policy.on_add(new_remote_host)
# we now have two local hosts and two remote hosts in separate dcs
qplan = list(policy.make_query_plan())
self.assertEqual(set(qplan[:2]), set([hosts[1], new_local_host]))
self.assertEqual(set(qplan[2:]), set([hosts[3], new_remote_host]))
# since we have hosts in dc9000, the distance shouldn't be IGNORED
self.assertEqual(policy.distance(new_remote_host), HostDistance.REMOTE)
class ExponentialReconnectionPolicyTest(unittest.TestCase):
def test_bad_vals(self):
self.assertRaises(ValueError, ExponentialReconnectionPolicy, -1, 0)
self.assertRaises(ValueError, ExponentialReconnectionPolicy, 0, -1)
self.assertRaises(ValueError, ExponentialReconnectionPolicy, 9000, 1)
def test_schedule(self):
policy = ExponentialReconnectionPolicy(base_delay=2, max_delay=100)
schedule = list(policy.new_schedule())
self.assertEqual(len(schedule), 64)
for i, delay in enumerate(schedule):
if i == 0:
self.assertEqual(delay, 2)
elif i < 6:
self.assertEqual(delay, schedule[i - 1] * 2)
else:
self.assertEqual(delay, 100)
class RetryPolicyTest(unittest.TestCase):
def test_read_timeout(self):
policy = RetryPolicy()
# if this is the second or greater attempt, rethrow
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=1, received_responses=2,
data_retrieved=True, retry_num=1)
self.assertEqual(retry, RetryPolicy.RETHROW)
# if we didn't get enough responses, rethrow
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=2, received_responses=1,
data_retrieved=True, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETHROW)
# if we got enough responses, but also got a data response, rethrow
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=2, received_responses=2,
data_retrieved=True, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETHROW)
# we got enough reponses but no data response, so retry
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=2, received_responses=2,
data_retrieved=False, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, "ONE")
def test_write_timeout(self):
policy = RetryPolicy()
# if this is the second or greater attempt, rethrow
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=WriteType.SIMPLE,
required_responses=1, received_responses=2, retry_num=1)
self.assertEqual(retry, RetryPolicy.RETHROW)
# if it's not a BATCH_LOG write, don't retry it
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=WriteType.SIMPLE,
required_responses=1, received_responses=2, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETHROW)
# retry BATCH_LOG writes regardless of received responses
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=WriteType.BATCH_LOG,
required_responses=10000, received_responses=1, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, "ONE")
class DowngradingConsistencyRetryPolicyTest(unittest.TestCase):
def test_read_timeout(self):
policy = DowngradingConsistencyRetryPolicy()
# if this is the second or greater attempt, rethrow
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=1, received_responses=2,
data_retrieved=True, retry_num=1)
self.assertEqual(retry, RetryPolicy.RETHROW)
# if we didn't get enough responses, retry at a lower consistency
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=3, received_responses=2,
data_retrieved=True, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, ConsistencyLevel.TWO)
# retry consistency level goes down based on the # of recv'd responses
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=3, received_responses=1,
data_retrieved=True, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, ConsistencyLevel.ONE)
# if we got no responses, rethrow
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=3, received_responses=0,
data_retrieved=True, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETHROW)
# if we got enough response but no data, retry
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=3, received_responses=3,
data_retrieved=False, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
# if we got enough responses, but also got a data response, rethrow
retry, consistency = policy.on_read_timeout(
query=None, consistency="ONE", required_responses=2, received_responses=2,
data_retrieved=True, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETHROW)
def test_write_timeout(self):
policy = DowngradingConsistencyRetryPolicy()
# if this is the second or greater attempt, rethrow
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=WriteType.SIMPLE,
required_responses=1, received_responses=2, retry_num=1)
self.assertEqual(retry, RetryPolicy.RETHROW)
# ignore failures on these types of writes
for write_type in (WriteType.SIMPLE, WriteType.BATCH, WriteType.COUNTER):
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=write_type,
required_responses=1, received_responses=2, retry_num=0)
self.assertEqual(retry, RetryPolicy.IGNORE)
# downgrade consistency level on unlogged batch writes
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=WriteType.UNLOGGED_BATCH,
required_responses=3, received_responses=1, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, ConsistencyLevel.ONE)
# retry batch log writes at the same consistency level
retry, consistency = policy.on_write_timeout(
query=None, consistency="ONE", write_type=WriteType.BATCH_LOG,
required_responses=3, received_responses=1, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, "ONE")
def test_unavailable(self):
policy = DowngradingConsistencyRetryPolicy()
# if this is the second or greater attempt, rethrow
retry, consistency = policy.on_unavailable(
query=None, consistency="ONE", required_replicas=3, alive_replicas=1, retry_num=1)
self.assertEqual(retry, RetryPolicy.RETHROW)
# downgrade consistency on unavailable exceptions
retry, consistency = policy.on_unavailable(
query=None, consistency="ONE", required_replicas=3, alive_replicas=1, retry_num=0)
self.assertEqual(retry, RetryPolicy.RETRY)
self.assertEqual(consistency, ConsistencyLevel.ONE)