def test_server_set(self):
"""Test various failure scenarios on server set implementation.
1. When a new server joins the set, the watcher should be notified.
2. When the underlying zk client disconnects and then recovers,
the server set should be transparent to server set participants
and watchers.
3. When the underlying zk client messes up beyond recovery,
the underlying client should be replaced, and this should be
transparent to server set participants and watchers.
"""
all_children = []
watcher_triggered = Event()
def server_set_watcher(children):
while all_children:
all_children.pop()
for child in children:
all_children.append(child)
watcher_triggered.set()
testutil.initialize_kazoo_client_manager(ZK_HOSTS)
client = KazooClientManager().get_client()
server_set = ServerSet(ServerSetTestCase.SERVER_SET_PATH,
ZK_HOSTS,
waiting_in_secs=0.01)
server_set.join(ServerSetTestCase.PORT_1, use_ip=True).join()
server_set.monitor(server_set_watcher).join()
watcher_triggered.wait(1)
# Now the server set should only contain end point 1
self.assertEqual(all_children, [ServerSetTestCase.END_POINT_1])
watcher_triggered.clear()
server_set.join(ServerSetTestCase.PORT_2, use_ip=True).join()
watcher_triggered.wait(1)
all_children.sort()
# Now the server set should contain both end point 1 and 2
self.assertEqual(all_children, ServerSetTestCase.END_POINTS)
# Test recoverable failure
client.stop()
watcher_triggered.clear()
client.start()
watcher_triggered.wait(1)
# Server set should remain the same when the client recovers
all_children.sort()
self.assertEqual(all_children, ServerSetTestCase.END_POINTS)
# Test client change
client.stop()
watcher_triggered.clear()
# give the monit greenlet a chance to detect failures
gevent.sleep(1)
# Assert the client has been replaced with a new one
self.assertFalse(KazooClientManager().get_client() is client)
watcher_triggered.wait(1)
# Server set should survive the underlying client being swapped out
all_children.sort()
self.assertEqual(all_children, ServerSetTestCase.END_POINTS)
def test_server_set(self):
"""Test various failure scenarios on server set implementation.
1. When a new server joins the set, the watcher should be notified.
2. When the underlying zk client disconnects and then recovers,
the server set should be transparent to server set participants
and watchers.
3. When the underlying zk client messes up beyond recovery,
the underlying client should be replaced, and this should be
transparent to server set participants and watchers.
"""
all_children = []
watcher_triggered = Event()
def server_set_watcher(children):
while all_children:
all_children.pop()
for child in children:
all_children.append(child)
watcher_triggered.set()
testutil.initialize_kazoo_client_manager(ZK_HOSTS)
client = KazooClientManager().get_client()
server_set = ServerSet(ServerSetTestCase.SERVER_SET_PATH,
ZK_HOSTS,
waiting_in_secs=0.01)
server_set.join(ServerSetTestCase.PORT_1, use_ip=True).join()
server_set.monitor(server_set_watcher).join()
watcher_triggered.wait(1)
# Now the server set should only contain end point 1
self.assertEqual(all_children, [ServerSetTestCase.END_POINT_1])
watcher_triggered.clear()
server_set.join(ServerSetTestCase.PORT_2, use_ip=True).join()
watcher_triggered.wait(1)
all_children.sort()
# Now the server set should contain both end point 1 and 2
self.assertEqual(all_children, ServerSetTestCase.END_POINTS)
# Test recoverable failure
client.stop()
watcher_triggered.clear()
client.start()
watcher_triggered.wait(1)
# Server set should remain the same when the client recovers
all_children.sort()
self.assertEqual(all_children, ServerSetTestCase.END_POINTS)
# Test client change
client.stop()
watcher_triggered.clear()
# give the monit greenlet a chance to detect failures
gevent.sleep(1)
# Assert the client has been replaced with a new one
self.assertFalse(KazooClientManager().get_client() is client)
watcher_triggered.wait(1)
# Server set should survive the underlying client being swapped out
all_children.sort()
self.assertEqual(all_children, ServerSetTestCase.END_POINTS)
def _place_watch(config, zk_path, command,
watch_type, max_wait_in_secs=0, alert_disabled=False):
"""
Place the watch for Config or Serverset giving the information extracted
from metaconfig.
"""
# If the ZK path is already added, skip the following steps
# in order to resolve conflicts.
if zk_path in _PATH_TO_COMMAND:
log.warn("Path %s has already been added to PATH_TO_COMMAND" % zk_path)
return False
if not _zk_path_exists(ZK_HOSTS, zk_path):
log.error("zk_path %s does not exist in zk_hosts %s, no watch is set."
% (zk_path, ZK_HOSTS))
# Save the configs that contain the nonexistent zk path for retry
_CONFIGS_WITH_NONEXISTENT_PATH.append(config)
return False
log.info("Creating Zookeeper data watcher for path %s of zk_hosts %s"
% (zk_path, ZK_HOSTS))
# Get the local file modification time if the file exists, else set to 0.
_get_and_set_local_file_modification_time(zk_path, command, watch_type)
if watch_type is not None and watch_type.lower() == 'serverset':
watcher = ServerSet(zk_path, ZK_HOSTS)
else:
watcher = DataWatcher(zk_path, ZK_HOSTS)
log.info(
"Associating command '%s' with watcher of path %s"
% (command, zk_path)
)
_PATH_TO_COMMAND[zk_path] = command
_PATH_TO_ALERT_DISABLED[zk_path] = alert_disabled
callback_func = functools.partial(
_run_command, zk_path, command, max_wait_in_secs, watch_type)
_PATH_TO_WATCHER[zk_path] = \
{"watcher": watcher, "func": callback_func, "watch_type": watch_type}
if watch_type == 'serverset':
watcher.monitor(callback_func)
else:
watcher.watch(callback_func)
return True
def _place_watch(config, zk_path, command,
watch_type, max_wait_in_secs=0, alert_disabled=False):
"""
Place the watch for Config or Serverset giving the information extracted
from metaconfig.
"""
# If the ZK path is already added, skip the following steps
# in order to resolve conflicts.
if zk_path in _PATH_TO_COMMAND:
log.warn("Path %s has already been added to PATH_TO_COMMAND" % zk_path)
return False
if not _zk_path_exists(ZK_HOSTS, zk_path):
log.error("zk_path %s does not exist in zk_hosts %s, no watch is set."
% (zk_path, ZK_HOSTS))
# Save the configs that contain the nonexistent zk path for retry
_CONFIGS_WITH_NONEXISTENT_PATH.append(config)
return False
log.info("Creating Zookeeper data watcher for path %s of zk_hosts %s"
% (zk_path, ZK_HOSTS))
# Get the local file modification time if the file exists, else set to 0.
_get_and_set_local_file_modification_time(zk_path, command, watch_type)
if watch_type is not None and watch_type.lower() == 'serverset':
watcher = ServerSet(zk_path, ZK_HOSTS)
else:
watcher = DataWatcher(zk_path, ZK_HOSTS)
log.info(
"Associating command '%s' with watcher of path %s"
% (command, zk_path)
)
_PATH_TO_COMMAND[zk_path] = command
_PATH_TO_ALERT_DISABLED[zk_path] = alert_disabled
if watch_type == 'serverset':
watcher.monitor(functools.partial(
_run_command, zk_path, command, max_wait_in_secs, watch_type))
else:
watcher.watch(functools.partial(
_run_command, zk_path, command, max_wait_in_secs, watch_type))
return True
def test_server_set(self):
"""Test various failure scenarios on server set implementation.
1. When a new server joins the set, the watcher should be notified.
In practice there is a daemon monitoring the server set change in
zk and update the local file.
2. When the underlying zk client disconnects and then recovers,
the server set should be transparent to server set participants
and watchers.
3. When the underlying zk client messes up beyond recovery,
it should be transparent to server set participants and watchers.
Although when a local file is being watched, now all the code paths
about the above behaviors got affected, we still want to test all the
scenarios to make sure nothing breaks when a file is used.
NOTE: to simulate the behavior in practice, when a server joins or
leaves, we assume that there is a daemon to make the corresponding
change to the local file.
"""
fd, tmp_file = tempfile.mkstemp()
all_children = []
watcher_triggered = Event()
def server_set_watcher(children):
while all_children:
all_children.pop()
for child in children:
all_children.append(child)
watcher_triggered.set()
testutil.initialize_kazoo_client_manager(ZK_HOSTS)
client = KazooClientManager().get_client()
server_set = ServerSet(ServerSetWithFileTestCase.SERVER_SET_PATH,
ZK_HOSTS,
waiting_in_secs=0.01,
file_path=tmp_file)
server_set.join(ServerSetWithFileTestCase.PORT_1, use_ip=False).join()
# update the local file manually here, suppose there is a daemon
with open(tmp_file, 'w') as f:
f.write(ServerSetWithFileTestCase.END_POINT_1)
gevent.sleep(1)
server_set.monitor(server_set_watcher).join()
watcher_triggered.wait(1)
# Now the server set should only contain end point 1
self.assertEqual(all_children, [ServerSetWithFileTestCase.END_POINT_1])
watcher_triggered.clear()
server_set.join(ServerSetWithFileTestCase.PORT_2, use_ip=False).join()
# update the local file manually here, suppose there is a daemon
with open(tmp_file, 'w') as f:
f.write(ServerSetWithFileTestCase.END_POINT_1 +
"\n" +
ServerSetWithFileTestCase.END_POINT_2)
gevent.sleep(1)
watcher_triggered.wait(1)
all_children.sort()
# Now the server set should contain both end point 1 and 2
self.assertEqual(all_children, ServerSetWithFileTestCase.END_POINTS)
# Test recoverable failure
client.stop()
watcher_triggered.clear()
client.start()
watcher_triggered.wait(1)
# Server set should remain the same when the client recovers
all_children.sort()
self.assertEqual(all_children, ServerSetWithFileTestCase.END_POINTS)
# Test client change
client.stop()
watcher_triggered.clear()
# give the monit greenlet a chance to detect failures
gevent.sleep(1)
watcher_triggered.wait(1)
# Server set should survive the underlying client being swapped out
all_children.sort()
self.assertEqual(all_children, ServerSetWithFileTestCase.END_POINTS)
self.FILE_WATCH._clear_all_watches()
os.remove(tmp_file)
def test_server_set(self):
"""Test various failure scenarios on server set implementation.
1. When a new server joins the set, the watcher should be notified.
In practice there is a daemon monitoring the server set change in
zk and update the local file.
2. When the underlying zk client disconnects and then recovers,
the server set should be transparent to server set participants
and watchers.
3. When the underlying zk client messes up beyond recovery,
it should be transparent to server set participants and watchers.
Although when a local file is being watched, now all the code paths
about the above behaviors got affected, we still want to test all the
scenarios to make sure nothing breaks when a file is used.
NOTE: to simulate the behavior in practice, when a server joins or
leaves, we assume that there is a daemon to make the corresponding
change to the local file.
"""
fd, tmp_file = tempfile.mkstemp()
all_children = []
watcher_triggered = Event()
def server_set_watcher(children):
while all_children:
all_children.pop()
for child in children:
all_children.append(child)
watcher_triggered.set()
testutil.initialize_kazoo_client_manager(ZK_HOSTS)
client = KazooClientManager().get_client()
server_set = ServerSet(ServerSetWithFileTestCase.SERVER_SET_PATH,
ZK_HOSTS,
waiting_in_secs=0.01,
file_path=tmp_file)
server_set.join(ServerSetWithFileTestCase.PORT_1, use_ip=False).join()
# update the local file manually here, suppose there is a daemon
with open(tmp_file, 'w') as f:
f.write(ServerSetWithFileTestCase.END_POINT_1)
gevent.sleep(1)
server_set.monitor(server_set_watcher).join()
watcher_triggered.wait(1)
# Now the server set should only contain end point 1
self.assertEqual(all_children, [ServerSetWithFileTestCase.END_POINT_1])
watcher_triggered.clear()
server_set.join(ServerSetWithFileTestCase.PORT_2, use_ip=False).join()
# update the local file manually here, suppose there is a daemon
with open(tmp_file, 'w') as f:
f.write(ServerSetWithFileTestCase.END_POINT_1 + "\n" +
ServerSetWithFileTestCase.END_POINT_2)
gevent.sleep(1)
watcher_triggered.wait(1)
all_children.sort()
# Now the server set should contain both end point 1 and 2
self.assertEqual(all_children, ServerSetWithFileTestCase.END_POINTS)
# Test recoverable failure
client.stop()
watcher_triggered.clear()
client.start()
watcher_triggered.wait(1)
# Server set should remain the same when the client recovers
all_children.sort()
self.assertEqual(all_children, ServerSetWithFileTestCase.END_POINTS)
# Test client change
client.stop()
watcher_triggered.clear()
# give the monit greenlet a chance to detect failures
gevent.sleep(1)
watcher_triggered.wait(1)
# Server set should survive the underlying client being swapped out
all_children.sort()
self.assertEqual(all_children, ServerSetWithFileTestCase.END_POINTS)
self.FILE_WATCH._clear_all_watches()
os.remove(tmp_file)
