def setUp(self):
self.redlock = ExtendableRedlock(get_servers_pool(active=1,
inactive=0))
self.redlock_with_51_servers_up_49_down = ExtendableRedlock(
get_servers_pool(active=51, inactive=49))
self.redlock_with_50_servers_up_50_down = ExtendableRedlock(
get_servers_pool(active=50, inactive=50))
def setUp(self):
self.redlock = ExtendableRedlock(get_servers_pool(active=1, inactive=0))
self.redlock_with_51_servers_up_49_down = ExtendableRedlock(get_servers_pool(active=51, inactive=49))
self.redlock_with_50_servers_up_50_down = ExtendableRedlock(get_servers_pool(active=50, inactive=50))
class ExtendableRedlockTest(unittest.TestCase):
@patch('redis.StrictRedis', new=FakeRedisCustom)
def setUp(self):
self.redlock = ExtendableRedlock(get_servers_pool(active=1, inactive=0))
self.redlock_with_51_servers_up_49_down = ExtendableRedlock(get_servers_pool(active=51, inactive=49))
self.redlock_with_50_servers_up_50_down = ExtendableRedlock(get_servers_pool(active=50, inactive=50))
def tearDown(self):
fakeredis.DATABASES = {}
def test_bad_connection_info(self):
with self.assertRaises(Warning):
Redlock([{"cat": "hog"}])
def test_should_be_able_to_lock_a_resource_after_it_has_been_unlocked(self):
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 10)
self.assertIsInstance(lock, Lock)
self.redlock_with_51_servers_up_49_down.unlock(lock)
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 10)
self.assertIsInstance(lock, Lock)
def test_safety_property_mutual_exclusion(self):
"""
At any given moment, only one client can hold a lock.
"""
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 100000)
self.assertIsInstance(lock, Lock)
bad = self.redlock_with_51_servers_up_49_down.lock("shorts", 10)
self.assertFalse(bad)
def test_liveness_property_A_deadlocks_free(self):
"""
Eventually it is always possible to acquire a lock,
even if the client that locked a resource crashed or gets partitioned.
"""
lock_A = self.redlock_with_51_servers_up_49_down.lock("shorts", 500)
self.assertIsInstance(lock_A, Lock)
sleep(1)
lock_B = self.redlock_with_51_servers_up_49_down.lock("shorts", 1000)
self.assertIsInstance(lock_B, Lock)
def test_liveness_property_B_fault_tolerance(self):
"""
As long as the majority of Redis nodes are up, clients are able to acquire and release locks.
"""
lock_with_majority = self.redlock_with_51_servers_up_49_down.lock("shorts", 100000)
self.assertIsInstance(lock_with_majority, Lock)
lock_without_majority = self.redlock_with_50_servers_up_50_down.lock("shorts", 100000)
self.assertEqual(lock_without_majority, False)
def test_locks_are_released_when_majority_is_not_reached(self):
"""
[...] clients that fail to acquire the majority of locks,
to release the (partially) acquired locks ASAP [...]
"""
lock = self.redlock_with_50_servers_up_50_down.lock("shorts", 10000)
self.assertEqual(lock, False)
for server in self.redlock_with_50_servers_up_50_down.servers:
self.assertEqual(server.get('shorts'), None)
def test_avoid_removing_locks_created_by_other_clients(self):
"""
[...] avoid removing a lock that was created by another client.
"""
lock_A = self.redlock.lock("shorts", 100000)
self.assertIsInstance(lock_A, Lock)
lock_B = Lock(validity=9000, resource='shorts', key='abcde')
self.redlock.unlock(lock_B)
for server in self.redlock.servers:
self.assertEqual(server.get('shorts'), lock_A.key)
def test_two_at_the_same_time_only_one_gets_it(self):
threads = []
threads_that_got_the_lock = []
def get_lock_and_register(thread_name, redlock, resource, output):
lock = redlock.lock(resource, 100000)
if lock:
output.append(thread_name)
for i in range(2):
thread = threading.Thread(
target=get_lock_and_register, args=(i, self.redlock, 'shorts', threads_that_got_the_lock)
)
thread.start()
threads.append(thread)
for t in threads:
t.join()
self.assertEqual(len(threads_that_got_the_lock), 1)
def test_a_lock_can_be_extended(self):
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 500)
extended = self.redlock_with_51_servers_up_49_down.extend(lock, 1000)
self.assertEqual(extended, True)
sleep(0.6)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(True))
def test_a_lock_cannot_be_extended_if_it_is_expired(self):
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 500)
sleep(0.75)
extended = self.redlock_with_51_servers_up_49_down.extend(lock, 1000)
self.assertEqual(extended, False)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(False))
def test_locks_have_a_close_to_ttl_validity(self):
requested_ttl_ms = 10000
how_close_ms = 500
lock_A = self.redlock.lock('pants', requested_ttl_ms)
self.assertIsInstance(lock_A, Lock)
self.assertGreaterEqual(lock_A.validity, requested_ttl_ms - how_close_ms)
def test_a_lock_is_always_valid_within_its_validity_time(self):
lock = self.redlock.lock('test_regular_lock', seconds_to_ms(30))
assert_that(self.redlock.is_valid(lock), is_(True))
def test_a_lock_goes_invalid_after_validity_time(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_goes_invalid', 350)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(True))
sleep(ms_to_seconds(lock.validity + 100))
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(False))
def test_a_lock_goes_invalid_if_majority_not_attained(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_goes_invalid', seconds_to_ms(30))
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(True))
twenty_five_servers_where_lock_is_valid = [s for s in self.redlock_with_51_servers_up_49_down.servers if
s.get(lock.resource) == lock.key][:25]
for server in twenty_five_servers_where_lock_is_valid:
server.delete(lock.resource)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(False))
def test_autoextend_automatically_extends_the_lock_expiry(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_autoextend', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock, every_ms=200, new_ttl=500):
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(True))
def test_autoextend_automatically_extends_the_lock_expiry_explicit_start_stop(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_autoextend', 500)
try:
self.redlock_with_51_servers_up_49_down.start_autoextend(lock, every_ms=200, new_ttl=500)
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(True))
finally:
self.redlock_with_51_servers_up_49_down.stop_autoextend(lock)
def test_autoextending_lock_unable_to_renew(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_unable_to_renew', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock, every_ms=100, new_ttl=500):
for server in self.redlock.servers:
server.flushall()
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(False))
def test_autoextend_is_not_valid_if_not_refreshed_fast_enough(self):
lock = self.redlock.lock('test_should_raise', 150)
with self.redlock_with_51_servers_up_49_down.autoextend(lock, every_ms=250, new_ttl=150):
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock), is_(False))
def test_autoextend_twice_is_an_error(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_autoextend', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock, every_ms=200, new_ttl=500):
with self.assertRaises(LockAutoextendAlreadyRunning):
self.redlock_with_51_servers_up_49_down.start_autoextend(lock, every_ms=200, new_ttl=500)
def test_autoextend_start_stop_start_stop(self):
lock = self.redlock_with_51_servers_up_49_down.lock('test_autoextend', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock, every_ms=200, new_ttl=500):
pass
with self.redlock_with_51_servers_up_49_down.autoextend(lock, every_ms=200, new_ttl=500):
pass
class ExtendableRedlockTest(unittest.TestCase):
@patch('redis.StrictRedis', new=FakeRedisCustom)
def setUp(self):
self.redlock = ExtendableRedlock(get_servers_pool(active=1,
inactive=0))
self.redlock_with_51_servers_up_49_down = ExtendableRedlock(
get_servers_pool(active=51, inactive=49))
self.redlock_with_50_servers_up_50_down = ExtendableRedlock(
get_servers_pool(active=50, inactive=50))
def tearDown(self):
fakeredis.DATABASES = {}
def test_bad_connection_info(self):
with self.assertRaises(Warning):
Redlock([{"cat": "hog"}])
def test_should_be_able_to_lock_a_resource_after_it_has_been_unlocked(
self):
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 10)
self.assertIsInstance(lock, Lock)
self.redlock_with_51_servers_up_49_down.unlock(lock)
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 10)
self.assertIsInstance(lock, Lock)
def test_safety_property_mutual_exclusion(self):
"""
At any given moment, only one client can hold a lock.
"""
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 100000)
self.assertIsInstance(lock, Lock)
bad = self.redlock_with_51_servers_up_49_down.lock("shorts", 10)
self.assertFalse(bad)
def test_liveness_property_A_deadlocks_free(self):
"""
Eventually it is always possible to acquire a lock,
even if the client that locked a resource crashed or gets partitioned.
"""
lock_A = self.redlock_with_51_servers_up_49_down.lock("shorts", 500)
self.assertIsInstance(lock_A, Lock)
sleep(1)
lock_B = self.redlock_with_51_servers_up_49_down.lock("shorts", 1000)
self.assertIsInstance(lock_B, Lock)
def test_liveness_property_B_fault_tolerance(self):
"""
As long as the majority of Redis nodes are up, clients are able to acquire and release locks.
"""
lock_with_majority = self.redlock_with_51_servers_up_49_down.lock(
"shorts", 100000)
self.assertIsInstance(lock_with_majority, Lock)
lock_without_majority = self.redlock_with_50_servers_up_50_down.lock(
"shorts", 100000)
self.assertEqual(lock_without_majority, False)
def test_locks_are_released_when_majority_is_not_reached(self):
"""
[...] clients that fail to acquire the majority of locks,
to release the (partially) acquired locks ASAP [...]
"""
lock = self.redlock_with_50_servers_up_50_down.lock("shorts", 10000)
self.assertEqual(lock, False)
for server in self.redlock_with_50_servers_up_50_down.servers:
self.assertEqual(server.get('shorts'), None)
def test_avoid_removing_locks_created_by_other_clients(self):
"""
[...] avoid removing a lock that was created by another client.
"""
lock_A = self.redlock.lock("shorts", 100000)
self.assertIsInstance(lock_A, Lock)
lock_B = Lock(validity=9000, resource='shorts', key='abcde')
self.redlock.unlock(lock_B)
for server in self.redlock.servers:
self.assertEqual(server.get('shorts'), lock_A.key)
def test_two_at_the_same_time_only_one_gets_it(self):
threads = []
threads_that_got_the_lock = []
def get_lock_and_register(thread_name, redlock, resource, output):
lock = redlock.lock(resource, 100000)
if lock:
output.append(thread_name)
for i in range(2):
thread = threading.Thread(target=get_lock_and_register,
args=(i, self.redlock, 'shorts',
threads_that_got_the_lock))
thread.start()
threads.append(thread)
for t in threads:
t.join()
self.assertEqual(len(threads_that_got_the_lock), 1)
def test_a_lock_can_be_extended(self):
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 500)
extended = self.redlock_with_51_servers_up_49_down.extend(lock, 1000)
self.assertEqual(extended, True)
sleep(0.6)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(True))
def test_a_lock_cannot_be_extended_if_it_is_expired(self):
lock = self.redlock_with_51_servers_up_49_down.lock("shorts", 500)
sleep(0.75)
extended = self.redlock_with_51_servers_up_49_down.extend(lock, 1000)
self.assertEqual(extended, False)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(False))
def test_locks_have_a_close_to_ttl_validity(self):
requested_ttl_ms = 10000
how_close_ms = 500
lock_A = self.redlock.lock('pants', requested_ttl_ms)
self.assertIsInstance(lock_A, Lock)
self.assertGreaterEqual(lock_A.validity,
requested_ttl_ms - how_close_ms)
def test_a_lock_is_always_valid_within_its_validity_time(self):
lock = self.redlock.lock('test_regular_lock', seconds_to_ms(30))
assert_that(self.redlock.is_valid(lock), is_(True))
def test_a_lock_goes_invalid_after_validity_time(self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_goes_invalid', 350)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(True))
sleep(ms_to_seconds(lock.validity + 100))
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(False))
def test_a_lock_goes_invalid_if_majority_not_attained(self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_goes_invalid', seconds_to_ms(30))
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(True))
twenty_five_servers_where_lock_is_valid = [
s for s in self.redlock_with_51_servers_up_49_down.servers
if s.get(lock.resource) == lock.key
][:25]
for server in twenty_five_servers_where_lock_is_valid:
server.delete(lock.resource)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(False))
def test_autoextend_automatically_extends_the_lock_expiry(self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_autoextend', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock,
every_ms=200,
new_ttl=500):
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(True))
def test_autoextend_automatically_extends_the_lock_expiry_explicit_start_stop(
self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_autoextend', 500)
try:
self.redlock_with_51_servers_up_49_down.start_autoextend(
lock, every_ms=200, new_ttl=500)
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(True))
finally:
self.redlock_with_51_servers_up_49_down.stop_autoextend(lock)
def test_autoextending_lock_unable_to_renew(self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_unable_to_renew', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock,
every_ms=100,
new_ttl=500):
for server in self.redlock.servers:
server.flushall()
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(False))
def test_autoextend_is_not_valid_if_not_refreshed_fast_enough(self):
lock = self.redlock.lock('test_should_raise', 150)
with self.redlock_with_51_servers_up_49_down.autoextend(lock,
every_ms=250,
new_ttl=150):
sleep(1)
assert_that(self.redlock_with_51_servers_up_49_down.is_valid(lock),
is_(False))
def test_autoextend_twice_is_an_error(self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_autoextend', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock,
every_ms=200,
new_ttl=500):
with self.assertRaises(LockAutoextendAlreadyRunning):
self.redlock_with_51_servers_up_49_down.start_autoextend(
lock, every_ms=200, new_ttl=500)
def test_autoextend_start_stop_start_stop(self):
lock = self.redlock_with_51_servers_up_49_down.lock(
'test_autoextend', 500)
with self.redlock_with_51_servers_up_49_down.autoextend(lock,
every_ms=200,
new_ttl=500):
pass
with self.redlock_with_51_servers_up_49_down.autoextend(lock,
every_ms=200,
new_ttl=500):
pass
