def failover(mb_urls, mb_client):
"""
Iterate through the list of message brokers provided and connect to the first available server. This will not
return until a message broker connection is established.
:param mb_urls: the list of message broker URLS of format [host:port, host:port]
:param mb_client: the initialized message broker client object
:return: a tuple of the connected message broker client, connected message broker IP address and connected
message broker port
"""
# Connection retry interval incrementer
message_broker_retry_timer = IncrementalCeilingListIterator(
[2, 2, 5, 5, 10, 10, 20, 20, 30, 30, 40, 40, 50, 50, 60],
False)
# Cycling through the provided mb urls until forever
while True:
retry_interval = message_broker_retry_timer.get_next_retry_interval()
for mb_url in mb_urls:
mb_ip, mb_port = mb_url.split(":")
EventSubscriber.log.debug(
"Trying to connect to the message broker with address %r:%r" % (mb_ip, mb_port))
try:
mb_client.connect(mb_ip, mb_port, 60)
return mb_client, mb_ip, mb_port
except:
# The message broker didn't respond well
EventSubscriber.log.debug("Could not connect to the message broker at %s:%s." % (mb_ip, mb_port))
EventSubscriber.log.debug(
"Could not connect to any of the message brokers provided. Retrying in %s seconds." % retry_interval)
time.sleep(retry_interval)
def failover(mb_urls, mb_client):
"""
Iterate through the list of message brokers provided and connect to the first available server. This will not
return until a message broker connection is established.
:param mb_urls: the list of message broker URLS of format [host:port, host:port]
:param mb_client: the initialized message broker client object
:return: a tuple of the connected message broker client, connected message broker IP address and connected
message broker port
"""
# Connection retry interval incrementer
message_broker_retry_timer = IncrementalCeilingListIterator(
[2, 2, 5, 5, 10, 10, 20, 20, 30, 30, 40, 40, 50, 50, 60],
False)
# Cycling through the provided mb urls until forever
while True:
retry_interval = message_broker_retry_timer.get_next_retry_interval()
for mb_url in mb_urls:
mb_ip, mb_port = mb_url.split(":")
EventSubscriber.log.debug(
"Trying to connect to the message broker with address %r:%r" % (mb_ip, mb_port))
try:
mb_client.connect(mb_ip, mb_port, 60)
return mb_client, mb_ip, mb_port
except:
# The message broker didn't respond well
EventSubscriber.log.info("Could not connect to the message broker at %s:%s." % (mb_ip, mb_port))
EventSubscriber.log.error(
"Could not connect to any of the message brokers provided. Retrying in %s seconds." % retry_interval)
time.sleep(retry_interval)
def publish(self, event):
if Config.mb_username is None:
auth = None
else:
auth = {"username": Config.mb_username, "password": Config.mb_password}
payload = event.to_json()
retry_iterator = IncrementalCeilingListIterator([2, 2, 5, 5, 10, 10, 20, 20, 30, 30, 40, 40, 50, 50, 60], False)
# Retry to publish the event until the timeout exceeds
while int(time.time()) - self.__start_time < (Config.mb_publisher_timeout * 1000):
retry_interval = retry_iterator.get_next_retry_interval()
for mb_url in Config.mb_urls.split(","):
mb_ip, mb_port = mb_url.split(":")
# start a thread to execute publish event
publisher_thread = Thread(target=self.__publish_event, args=(event, mb_ip, mb_port, auth, payload))
publisher_thread.setDaemon(True)
publisher_thread.setName("MBEventPublisherThreadForEvent%s" % event.__class__.__name__)
self.__log.debug("Starting a publisher thread for event %s " % event.__class__.__name__)
publisher_thread.start()
# give sometime for the thread to complete
time.sleep(5)
# check if thread is still running and notify
if publisher_thread.isAlive():
self.__log.debug(
"Event publishing timed out before succeeding. The message broker could be offline."
)
# check if publish.single() succeeded
try:
published = self.__msg_queue.get(block=False)
except Empty:
published = False
if published:
return True
# All the brokers on the list were offline
self.__log.debug(
"Could not publish event to any of the provided message brokers. Retrying in %s seconds."
% retry_interval
)
time.sleep(retry_interval)
# Even publisher timeout exceeded
self.__log.warn(
"Could not publish event to any of the provided message brokers before "
"the timeout [%s] exceeded. The event will be dropped." % Config.mb_publisher_timeout
)
return False
def publish(self, event):
if Config.mb_username is None:
auth = None
else:
auth = {"username": Config.mb_username, "password": Config.mb_password}
payload = event.to_json()
retry_iterator = IncrementalCeilingListIterator([2, 2, 5, 5, 10, 10, 20, 20, 30, 30, 40, 40, 50, 50, 60], False)
# Retry to publish the event until the timeout exceeds
while int(time.time()) - self.__start_time < (Config.mb_publisher_timeout * 1000):
retry_interval = retry_iterator.get_next_retry_interval()
for mb_url in Config.mb_urls.split(","):
mb_ip, mb_port = mb_url.split(":")
# start a thread to execute publish event
publisher_thread = Thread(target=self.__publish_event, args=(event, mb_ip, mb_port, auth, payload))
publisher_thread.start()
# give sometime for the thread to complete
time.sleep(5)
# check if thread is still running and notify
if publisher_thread.isAlive():
self.__log.debug(
"Event publishing timed out before succeeding. The message broker could be offline.")
# check if publish.single() succeeded
try:
published = self.__msg_queue.get(block=False)
except Empty:
published = False
if published:
return True
# All the brokers on the list were offline
self.__log.debug(
"Could not publish event to any of the provided message brokers. Retrying in %s seconds."
% retry_interval)
time.sleep(retry_interval)
# Even publisher timeout exceeded
self.__log.warn("Could not publish event to any of the provided message brokers before "
"the timeout [%s] exceeded. The event will be dropped." % Config.mb_publisher_timeout)
return False
