def close(self, exception=None):
"""
Close down the handler. If the handler has already closed,
this will be a no op. An optional exception can be passed in to
indicate that the handler was shutdown due to error.
:param exception: An optional exception if the handler is closing
due to an error.
:type exception: Exception
Example:
.. literalinclude:: ../examples/test_examples_eventhub.py
:start-after: [START eventhub_client_receiver_close]
:end-before: [END eventhub_client_receiver_close]
:language: python
:dedent: 4
:caption: Close down the handler.
"""
self.running = False
if self.error:
return
if isinstance(exception, errors.LinkRedirect):
self.redirected = exception
elif isinstance(exception, EventHubError):
self.error = exception
elif exception:
self.error = EventHubError(str(exception))
else:
self.error = EventHubError("This receive handler is now closed.")
self._handler.close()
def receive(self, max_batch_size=None, timeout=None):
"""
Receive events from the EventHub.
:param max_batch_size: Receive a batch of events. Batch size will
be up to the maximum specified, but will return as soon as service
returns no new events. If combined with a timeout and no events are
retrieve before the time, the result will be empty. If no batch
size is supplied, the prefetch size will be the maximum.
:type max_batch_size: int
:rtype: list[~azure.eventhub.common.EventData]
"""
if self.error:
raise self.error
try:
timeout_ms = 1000 * timeout if timeout else 0
message_batch = self._handler.receive_message_batch(
max_batch_size=max_batch_size, timeout=timeout_ms)
data_batch = []
for message in message_batch:
event_data = EventData(message=message)
self.offset = event_data.offset
data_batch.append(event_data)
return data_batch
except errors.LinkDetach as detach:
error = EventHubError(str(detach))
self.close(exception=error)
raise error
except Exception as e:
error = EventHubError("Receive failed: {}".format(e))
self.close(exception=error)
raise error
def wait(self):
"""
Wait until all transferred events have been sent.
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to send until client has been started.")
try:
self._handler.wait()
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
self.reconnect()
else:
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
self.reconnect()
else:
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
raise EventHubError("Send failed: {}".format(e))
def send(self, event_data):
"""
Sends an event data and blocks until acknowledgement is
received or operation times out.
:param event_data: The event to be sent.
:type event_data: ~azure.eventhub.common.EventData
:raises: ~azure.eventhub.common.EventHubError if the message fails to
send.
:return: The outcome of the message send.
:rtype: ~uamqp.constants.MessageSendResult
"""
if self.error:
raise self.error
if event_data.partition_key and self.partition:
raise ValueError(
"EventData partition key cannot be used with a partition sender."
)
event_data.message.on_send_complete = self._on_outcome
try:
self._handler.send_message(event_data.message)
if self._outcome != constants.MessageSendResult.Ok:
raise Sender._error(self._outcome, self._condition)
except errors.LinkDetach as detach:
error = EventHubError(str(detach))
self.close(exception=error)
raise error
except Exception as e:
error = EventHubError("Send failed: {}".format(e))
self.close(exception=error)
raise error
else:
return self._outcome
def _reconnect(self): # pylint: disable=too-many-statements
# pylint: disable=protected-access
alt_creds = {
"username": self.client._auth_config.get("iot_username"),
"password": self.client._auth_config.get("iot_password")}
self._handler.close()
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset.selector())
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(**alt_creds),
debug=self.client.debug,
prefetch=self.prefetch,
link_properties=self.properties,
timeout=self.timeout,
error_policy=self.retry_policy,
keep_alive_interval=self.keep_alive,
client_name=self.name,
properties=self.client.create_properties())
try:
self._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
return True
except errors.TokenExpired as shutdown:
log.info("Receiver disconnected due to token expiry. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
return False
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
return False
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.AMQPConnectionError as shutdown:
if str(shutdown).startswith("Unable to open authentication session") and self.auto_reconnect:
log.info("Receiver couldn't authenticate. Attempting reconnect.")
return False
log.info("Receiver connection error (%r). Shutting down.", shutdown)
error = EventHubError(str(shutdown))
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receiver reconnect failed: {}".format(e))
self.close(exception=error)
raise error
def send(self, event_data):
"""
Sends an event data and blocks until acknowledgement is
received or operation times out.
:param event_data: The event to be sent.
:type event_data: ~azure.eventhub.common.EventData
:raises: ~azure.eventhub.common.EventHubError if the message fails to
send.
:return: The outcome of the message send.
:rtype: ~uamqp.constants.MessageSendResult
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to send until client has been started.")
if event_data.partition_key and self.partition:
raise ValueError(
"EventData partition key cannot be used with a partition sender."
)
event_data.message.on_send_complete = self._on_outcome
try:
self._handler.send_message(event_data.message)
if self._outcome != constants.MessageSendResult.Ok:
raise Sender._error(self._outcome, self._condition)
except errors.MessageException as failed:
error = EventHubError(str(failed), failed)
self.close(exception=error)
raise error
except (errors.TokenExpired, errors.AuthenticationException):
log.info(
"Sender disconnected due to token error. Attempting reconnect."
)
self.reconnect()
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
self.reconnect()
else:
log.info("Sender detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
self.reconnect()
else:
log.info("Sender detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Send failed: {}".format(e))
self.close(exception=error)
raise error
else:
return self._outcome
def _handle_redirect(self, redirects):
if len(redirects) != len(self.clients):
raise EventHubError("Some clients are attempting to redirect the connection.")
if not all(r.hostname == redirects[0].hostname for r in redirects):
raise EventHubError("Multiple clients attempting to redirect to different hosts.")
self._process_redirect_uri(redirects[0])
for client in self.clients:
client.open()
def receive(self, max_batch_size=None, timeout=None):
"""
Receive events from the EventHub.
:param max_batch_size: Receive a batch of events. Batch size will
be up to the maximum specified, but will return as soon as service
returns no new events. If combined with a timeout and no events are
retrieve before the time, the result will be empty. If no batch
size is supplied, the prefetch size will be the maximum.
:type max_batch_size: int
:rtype: list[~azure.eventhub.common.EventData]
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to receive until client has been started.")
data_batch = []
try:
timeout_ms = 1000 * timeout if timeout else 0
message_batch = self._handler.receive_message_batch(
max_batch_size=max_batch_size,
timeout=timeout_ms)
for message in message_batch:
event_data = EventData(message=message)
self.offset = event_data.offset
data_batch.append(event_data)
return data_batch
except (errors.TokenExpired, errors.AuthenticationException):
log.info("Receiver disconnected due to token error. Attempting reconnect.")
self.reconnect()
return data_batch
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
self.reconnect()
return data_batch
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
self.reconnect()
return data_batch
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receive failed: {}".format(e))
self.close(exception=error)
raise error
def _handle_redirect(self, redirects):
if len(redirects) != len(self.clients):
raise EventHubError(
"Some clients are attempting to redirect the connection.")
if not all(r.hostname == redirects[0].hostname for r in redirects):
raise EventHubError(
"Multiple clients attempting to redirect to different hosts.")
self.auth = self._create_auth(redirects[0].address.decode('utf-8'),
**self._auth_config)
self.connection.redirect(redirects[0], self.auth)
for client in self.clients:
client.open(self.connection)
def _reconnect(self):
# pylint: disable=protected-access
self._handler.close()
unsent_events = self._handler.pending_messages
self._handler = SendClient(self.target,
auth=self.client.get_auth(),
debug=self.client.debug,
msg_timeout=self.timeout,
error_policy=self.retry_policy,
keep_alive_interval=self.keep_alive,
client_name=self.name,
properties=self.client.create_properties())
try:
self._handler.open()
self._handler.queue_message(*unsent_events)
self._handler.wait()
return True
except errors.TokenExpired as shutdown:
log.info("Sender disconnected due to token expiry. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
return False
log.info("Sender reconnect failed. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
return False
log.info("Sender reconnect failed. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.AMQPConnectionError as shutdown:
if str(shutdown).startswith("Unable to open authentication session"
) and self.auto_reconnect:
log.info("Sender couldn't authenticate. Attempting reconnect.")
return False
log.info("Sender connection error (%r). Shutting down.", shutdown)
error = EventHubError(str(shutdown))
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Sender Reconnect failed: {}".format(e))
self.close(exception=error)
raise error
def run(self):
"""
Run the EventHubClient in blocking mode.
Opens the connection and starts running all Sender/Receiver clients.
Returns a list of the start up results. For a succcesful client start the
result will be `None`, otherwise the exception raised.
If all clients failed to start, then run will fail, shut down the connection
and raise an exception.
If at least one client starts up successfully the run command will succeed.
:rtype: list[~azure.eventhub.common.EventHubError]
"""
log.info("%r: Starting %r clients", self.container_id, len(self.clients))
try:
self._start_clients()
redirects = [c.redirected for c in self.clients if c.redirected]
failed = [c.error for c in self.clients if c.error]
if failed and len(failed) == len(self.clients):
log.warning("%r: All clients failed to start.", self.container_id)
raise failed[0]
if failed:
log.warning("%r: %r clients failed to start.", self.container_id, len(failed))
elif redirects:
self._handle_redirect(redirects)
except EventHubError:
self.stop()
raise
except Exception as e:
self.stop()
raise EventHubError(str(e))
return failed
def reconnect(self):
"""If the Receiver was disconnected from the service with
a retryable error - attempt to reconnect."""
# pylint: disable=protected-access
alt_creds = {
"username": self.client._auth_config.get("iot_username"),
"password": self.client._auth_config.get("iot_password")
}
self._handler.close()
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset.selector())
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(**alt_creds),
debug=self.client.debug,
prefetch=self.prefetch,
link_properties=self.properties,
timeout=self.timeout,
error_policy=self.retry_policy,
keep_alive_interval=self.keep_alive,
client_name=self.name,
properties=self.client.create_properties())
try:
self._handler.open()
while not self.has_started():
self._handler._connection.work()
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
self.reconnect()
else:
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
self.reconnect()
else:
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
error = EventHubError("Receiver reconnect failed: {}".format(e))
self.close(exception=error)
raise error
def wait(self):
"""
Wait until all transferred events have been sent.
Example:
.. literalinclude:: ../examples/test_examples_eventhub.py
:start-after: [START eventhub_client_transfer]
:end-before: [END eventhub_client_transfer]
:language: python
:dedent: 4
:caption: Wait until all transferred events have been sent.
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to send until client has been started.")
try:
self._handler.wait()
except (errors.TokenExpired, errors.AuthenticationException):
log.info("Sender disconnected due to token error. Attempting reconnect.")
self.reconnect()
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
self.reconnect()
else:
log.info("Sender detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
self.reconnect()
else:
log.info("Sender detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r).", e)
raise EventHubError("Send failed: {}".format(e))
def wait(self):
"""
Wait until all transferred events have been sent.
"""
if self.error:
raise self.error
try:
self._handler.wait()
except Exception as e:
raise EventHubError("Send failed: {}".format(e))
def close(self, exception=None):
"""
Close down the handler. If the handler has already closed,
this will be a no op. An optional exception can be passed in to
indicate that the handler was shutdown due to error.
:param exception: An optional exception if the handler is closing
due to an error.
:type exception: Exception
"""
if self.error:
return
elif isinstance(exception, errors.LinkRedirect):
self.redirected = exception
elif isinstance(exception, EventHubError):
self.error = exception
elif exception:
self.error = EventHubError(str(exception))
else:
self.error = EventHubError("This receive handler is now closed.")
self._handler.close()
def reconnect(self):
"""If the Sender was disconnected from the service with
a retryable error - attempt to reconnect."""
# pylint: disable=protected-access
self._handler.close()
unsent_events = self._handler.pending_messages
self._handler = SendClient(self.target,
auth=self.client.get_auth(),
debug=self.client.debug,
msg_timeout=self.timeout,
error_policy=self.retry_policy,
keep_alive_interval=self.keep_alive,
client_name=self.name,
properties=self.client.create_properties())
try:
self._handler.open()
self._handler.queue_message(*unsent_events)
self._handler.wait()
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
self.reconnect()
else:
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
self.reconnect()
else:
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
error = EventHubError("Sender Reconnect failed: {}".format(e))
self.close(exception=error)
raise error
def wait(self):
"""
Wait until all transferred events have been sent.
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to send until client has been started.")
try:
self._handler.wait()
except (errors.TokenExpired, errors.AuthenticationException):
log.info(
"Sender disconnected due to token error. Attempting reconnect."
)
self.reconnect()
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
self.reconnect()
else:
log.info("Sender detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Sender detached. Attempting reconnect.")
self.reconnect()
else:
log.info("Sender detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r).", e)
raise EventHubError("Send failed: {}".format(e))
def has_started(self):
"""
Whether the handler has completed all start up processes such as
establishing the connection, session, link and authentication, and
is not ready to process messages.
:rtype: bool
"""
# pylint: disable=protected-access
timeout = False
auth_in_progress = False
if self._handler._connection.cbs:
timeout, auth_in_progress = self._handler._auth.handle_token()
if timeout:
raise EventHubError("Authorization timeout.")
if auth_in_progress:
return False
if not self._handler._client_ready():
return False
return True
def _error(outcome, condition):
return None if outcome == constants.MessageSendResult.Ok else EventHubError(
outcome, condition)