def __init__(self):
signal.signal(signal.SIGINT, self._handle_sig_event)
signal.signal(signal.SIGTERM, self._handle_sig_event)
self._prev_connection_state = None
self._zoo_keeper = ZooKeeper(self._zk_listener)
self._zoo_keeper.start()
self._configuration = Configuration(self._zoo_keeper)
self._task_server = TaskServer(self._configuration, self._zoo_keeper)
self._data_store = DataStore(self._configuration, self._zoo_keeper,
self._task_server)
self._web_server = WebServer(self._configuration, self._data_store,
self._task_server, self._zoo_keeper)
class Session(object):
def __init__(self):
signal.signal(signal.SIGINT, self._handle_sig_event)
signal.signal(signal.SIGTERM, self._handle_sig_event)
self._prev_connection_state = None
self._zoo_keeper = ZooKeeper(self._zk_listener)
self._zoo_keeper.start()
self._configuration = Configuration(self._zoo_keeper)
self._task_server = TaskServer(self._configuration, self._zoo_keeper)
self._data_store = DataStore(self._configuration, self._zoo_keeper,
self._task_server)
self._web_server = WebServer(self._configuration, self._data_store,
self._task_server, self._zoo_keeper)
def start(self):
self._data_store.load()
self._web_server.start()
def stop(self):
self._web_server.stop()
self._zoo_keeper.stop()
def _handle_sig_event(self, signum, frame):
logging.info("Signal handler called with signal {0}".format(signum))
self.stop()
def _zk_listener(self, state):
"""
The callback function that runs when the connection state to Zookeeper
changes.
Either passes or immediately spawns a new thread that resets any
watches, etc., so that it can listen to future connection state changes.
"""
try:
logging.info('Zookeeper Connection went from {0} to {1}'
.format(self._prev_connection_state, state))
if self._prev_connection_state is None \
and state == KazooState.CONNECTED:
pass
elif self._prev_connection_state == KazooState.LOST \
and state == KazooState.CONNECTED:
logging.info('Connection restored. Initiating data reload.')
self._zoo_keeper.kazoo.handler.spawn(self._data_store.reload)
elif self._prev_connection_state == KazooState.CONNECTED \
and state == KazooState.SUSPENDED:
pass
elif self._prev_connection_state == KazooState.CONNECTED \
and state == KazooState.LOST:
pass
elif self._prev_connection_state == KazooState.SUSPENDED \
and state == KazooState.LOST:
pass
elif self._prev_connection_state == KazooState.SUSPENDED \
and state == KazooState.CONNECTED:
logging.info('Connection restored. Initiating data reload.')
self._zoo_keeper.kazoo.handler.spawn(self._data_store.reload)
elif state == KazooState.CONNECTED:
logging.info('Connection restored. Initiating data reload.')
self._zoo_keeper.kazoo.handler.spawn(self._data_store.reload)
else:
logging.info('Zookeeper Connection in unknown state: {0}'
.format(state))
return
self._prev_connection_state = state
except Exception:
logging.exception('An uncaught exception has occurred')