1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
|
import uuid
import threading
import time
import mock
from kazoo.exceptions import LockTimeout
from kazoo.testing import KazooTestCase
from kazoo.recipe.partitioner import PartitionState
class SlowLockMock:
"""Emulates a slow ZooKeeper lock."""
default_delay_time = 3
def __init__(self, client, lock, delay_time=None):
self._client = client
self._lock = lock
self.delay_time = (
self.default_delay_time if delay_time is None else delay_time
)
def acquire(self, timeout=None):
sleep = self._client.handler.sleep_func
sleep(self.delay_time)
if timeout is None:
return self._lock.acquire()
start_time = time.time()
while time.time() - start_time < timeout:
if self._lock.acquire(False):
return True
sleep(0.1)
raise LockTimeout("Mocked slow lock has timed out.")
def release(self):
self._lock.release()
class KazooPartitionerTests(KazooTestCase):
@staticmethod
def make_event():
return threading.Event()
def setUp(self):
super(KazooPartitionerTests, self).setUp()
self.path = "/" + uuid.uuid4().hex
self.__partitioners = []
def test_party_of_one(self):
self.__create_partitioner(size=3)
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0, 1, 2])
self.__finish()
def test_party_of_two(self):
for i in range(2):
self.__create_partitioner(size=2, identifier=str(i))
self.__wait_for_acquire()
self.__assert_partitions([0], [1])
self.__partitioners[0].finish()
self.__wait()
assert self.__partitioners[1].release
self.__partitioners[1].finish()
def test_party_expansion(self):
for i in range(2):
self.__create_partitioner(size=3, identifier=str(i))
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0, 2], [1])
for partitioner in self.__partitioners:
partitioner.state_change_event.clear()
# Add another partition, wait till they settle
self.__create_partitioner(size=3, identifier="2")
self.__wait()
self.__assert_state(
PartitionState.RELEASE, partitioners=self.__partitioners[:-1]
)
for partitioner in self.__partitioners[-1]:
assert partitioner.state_change_event.is_set()
self.__release(self.__partitioners[:-1])
self.__wait_for_acquire()
self.__assert_partitions([0], [1], [2])
self.__finish()
def test_more_members_than_set_items(self):
for i in range(2):
self.__create_partitioner(size=1, identifier=str(i))
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0], [])
self.__finish()
def test_party_session_failure(self):
partitioner = self.__create_partitioner(size=3)
self.__wait_for_acquire()
assert partitioner.state == PartitionState.ACQUIRED
# simulate session failure
partitioner._fail_out()
partitioner.release_set()
assert partitioner.failed is True
def test_connection_loss(self):
self.__create_partitioner(identifier="0", size=3)
self.__create_partitioner(identifier="1", size=3)
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0, 2], [1])
# Emulate connection loss
self.lose_connection(self.make_event)
self.__assert_state(PartitionState.RELEASE)
self.__release()
# Check that partitioners settle after connection loss
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0, 2], [1])
# Check that partitioners react on new events after connection loss
self.__create_partitioner(identifier="2", size=3)
self.__wait()
self.__assert_state(
PartitionState.RELEASE, partitioners=self.__partitioners[:-1]
)
self.__release(partitioners=self.__partitioners[:-1])
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0], [1], [2])
def test_race_condition_new_partitioner_during_the_lock(self):
locks = {}
def get_lock(path):
lock = locks.setdefault(path, self.client.handler.lock_object())
return SlowLockMock(self.client, lock)
with mock.patch.object(self.client, "Lock", side_effect=get_lock):
# Create first partitioner. It will start to acquire the set
# members.
self.__create_partitioner(identifier="0", size=2)
# Wait until the first partitioner has acquired first lock and
# started to acquire the second lock.
self.client.handler.sleep_func(SlowLockMock.default_delay_time + 1)
# Create the second partitioner a the time when the first
# partitioner is in the process of acquiring the lock that should
# belong to the second partitioner.
self.__create_partitioner(identifier="1", size=2)
# The first partitioner should acquire the both locks but then it
# must notice that the party has changed and it must reacquire
# the set. No deadlocks must happen.
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0], [1])
def test_race_condition_new_partitioner_steals_the_lock(self):
locks = {}
def get_lock(path):
new_lock = self.client.handler.lock_object()
lock = locks.setdefault(path, new_lock)
if lock is new_lock:
# The first partitioner will be delayed
delay_time = SlowLockMock.default_delay_time
else:
# The second partitioner won't be delayed
delay_time = 0
return SlowLockMock(self.client, lock, delay_time=delay_time)
with mock.patch.object(self.client, "Lock", side_effect=get_lock):
# Create first partitioner. It will start to acquire the set
# members.
self.__create_partitioner(identifier="0", size=2)
# Wait until the first partitioner has acquired first lock and
# started to acquire the second lock.
self.client.handler.sleep_func(SlowLockMock.default_delay_time + 1)
# Create the second partitioner a the time when the first
# partitioner is in the process of acquiring the lock that should
# belong to the second partitioner. The second partitioner should
# steal the lock because it won't be delayed.
self.__create_partitioner(identifier="1", size=2)
# The first partitioner should fail to acquire the second lock and
# must notice that the party has changed and it must reacquire the
# set. No deadlocks must happen.
self.__wait_for_acquire()
self.__assert_state(PartitionState.ACQUIRED)
self.__assert_partitions([0], [1])
def __create_partitioner(self, size, identifier=None):
partitioner = self.client.SetPartitioner(
self.path,
set=range(size),
time_boundary=0.2,
identifier=identifier,
)
self.__partitioners.append(partitioner)
return partitioner
def __wait_for_acquire(self):
for partitioner in self.__partitioners:
partitioner.wait_for_acquire(14)
def __assert_state(self, state, partitioners=None):
if partitioners is None:
partitioners = self.__partitioners
for partitioner in partitioners:
assert partitioner.state == state
def __assert_partitions(self, *partitions):
assert len(partitions) == len(self.__partitioners)
for partitioner, own_partitions in zip(
self.__partitioners, partitions
):
assert list(partitioner) == own_partitions
def __wait(self):
time.sleep(0.1)
def __release(self, partitioners=None):
if partitioners is None:
partitioners = self.__partitioners
for partitioner in partitioners:
partitioner.release_set()
def __finish(self):
for partitioner in self.__partitioners:
partitioner.finish()
|