def test_callbacks(self):
manager = ClusterManager(self.client, "/home/my_cluster")
# Set up 2 listeners.
instance1 = ServiceInstance(Endpoint("host1", 10000))
handler1 = CallbackHandler()
listener1 = ClusterListener(self.client, "/home/my_cluster", instance1,
handler1.promotion_callback,
handler1.demotion_callback,
handler1.master_callback,
handler1.termination_callback)
listener1.start()
member1 = manager.add_member(instance1)
instance2 = ServiceInstance(Endpoint("host2", 10000))
handler2 = CallbackHandler()
listener2 = ClusterListener(self.client, "/home/my_cluster", instance2,
handler2.promotion_callback,
handler2.demotion_callback,
handler2.master_callback)
listener2.start()
member2 = manager.add_member(instance2)
# Test promotion.
manager.promote_member(member1)
assert handler1.promoted.wait(1)
assert handler2.detected.get(True, 1) == instance1
assert (self.storage.paths["/home/my_cluster/master/member_0000000000"]
["data"] == ServiceInstance.pack(instance1))
assert (self.storage.paths["/home/my_cluster/slaves/member_0000000001"]
["data"] == ServiceInstance.pack(instance2))
manager.promote_member(member2)
assert handler1.demoted.wait(1)
assert handler2.promoted.wait(1)
assert (self.storage.paths["/home/my_cluster/master/member_0000000001"]
["data"] == ServiceInstance.pack(instance2))
assert "/home/my_cluster/master/member_0000000000" not in self.storage.paths
manager.remove_member(member2)
assert handler2.demoted.wait(1)
# Test removing cluster.
manager.remove_member(member1)
manager.delete_cluster()
assert handler1.terminated.wait(1)
def test_invalid_znode(self):
instance1 = ServiceInstance(Endpoint("host1", 10000))
handler1 = CallbackHandler()
listener1 = ClusterListener(self.client, "/home/my_cluster", instance1,
handler1.promotion_callback,
handler1.demotion_callback,
handler1.master_callback)
listener1.start()
self.client.ensure_path("/home/my_cluster/master")
self.client.create("/home/my_cluster/master/member_",
"Invalid Data",
sequence=True)
# Invalid ZNode data translates into a 'None' return.
assert handler1.detected.get(True, 1) is None
def __init__(self, self_instance, kazoo, cluster_root, installer,
task_control, state_manager):
"""
:param self_instance: The local ServiceInstance associated with this task runner.
:param kazoo: Kazoo client, it should be started before being passed in.
:param cluster_root: The ZooKeeper root path for *this cluster*.
:param installer: The PackageInstaller for MySQL.
:param task_control: The TaskControl that interacts with the task process.
:param state_manager: The StateManager for managing the executor state.
"""
self._installer = installer
self._env = None # The environment variables for the 'task_control' commands. Set by the
# installer.
self._task_control = task_control
self._state_manager = state_manager
self._lock = threading.Lock()
self._popen = None # The singleton task process started by '_task_control'.
self._started = False # Indicates whether start() has already been called.
self._stopping = False # Indicates whether stop() has already been called.
self._exited = threading.Event(
) # Set when the task process has exited.
self._result = Queue.Queue(
) # The returncode returned by the task process or an exception.
# Public events and queue.
self.promoted = threading.Event()
self.demoted = threading.Event()
self.master = Queue.Queue() # Set when a master change is detected.
self._kazoo = kazoo
self._listener = ClusterListener(kazoo,
cluster_root,
self_instance,
promotion_callback=self._on_promote,
demotion_callback=self._on_demote,
master_callback=self._on_master_change
) # Listener started by start().
