def get_addresses(self):
launcher = SqsLauncher(self.service_discovery_address)
launcher.launch_message({
'command': 'hello',
'node_name': self.node_id,
'node_address': self.node_id
})
def _send_read_response(self, client_id, key, value):
launcher = SqsLauncher(client_id)
launcher.launch_message({
'command': 'read_response',
'key': key,
'value': value
})
def _send_response(self, id):
launcher = SqsLauncher(id['client_id'])
launcher.launch_message({
'command': 'write_response',
'response': 'accepted',
'id': id['time']
})
def _send_proposal_accepted(self, key):
launcher = SqsLauncher(self.coordinator_address)
launcher.launch_message({
'command': 'accept_to_coordinator',
'key': key,
'id': self.accepted[key]['proposed_id']
})
def _start_listening(self):
# TODO consider incorporating output processing from here: https://github.com/debrouwere/sqs-antenna/blob/master/antenna/__init__.py
while True:
messages = self._client.receive_message(
QueueUrl=self._queue_url,
MessageAttributeNames=self._message_attribute_names,
AttributeNames=self._attribute_names,
)
if 'Messages' in messages:
sqs_logger.info(
str(len(messages['Messages'])) + " messages received")
for m in messages['Messages']:
receipt_handle = m['ReceiptHandle']
m_body = m['Body']
message_attribs = None
attribs = None
# catch problems with malformed JSON, usually a result of someone writing poor JSON directly in the AWS console
try:
params_dict = json.loads(m_body)
except:
sqs_logger.warning(
"Unable to parse message - JSON is not formatted properly"
)
continue
if 'MessageAttributes' in m:
message_attribs = m['MessageAttributes']
if 'Attributes' in m:
attribs = m['Attributes']
try:
if self._force_delete:
self._client.delete_message(
QueueUrl=self._queue_url,
ReceiptHandle=receipt_handle)
self.handle_message(params_dict, message_attribs,
attribs, receipt_handle)
else:
self.handle_message(params_dict, message_attribs,
attribs, receipt_handle)
self._client.delete_message(
QueueUrl=self._queue_url,
ReceiptHandle=receipt_handle)
except Exception as ex:
# need exception logtype to log stack trace
sqs_logger.exception(ex)
if self._error_queue_name:
exc_type, exc_obj, exc_tb = sys.exc_info()
sqs_logger.info("Pushing exception to error queue")
error_launcher = SqsLauncher(
self._error_queue_name, True)
error_launcher.launch_message({
'exception_type':
str(exc_type),
'error_message':
str(ex.args)
})
else:
time.sleep(self._poll_interval)
def _send_accepted(self, quorum):
for node_address in self.nodes_addresses:
launcher = SqsLauncher(node_address)
launcher.launch_message({
'command': 'accepted',
'key': quorum['key'],
'id': quorum['id']
})
def _send_alive_msg(self):
launcher = SqsLauncher(self.service_discovery_address)
launcher.launch_message(({
'command':
'alive',
'node_id':
os.environ.get('NODE_ID', 'iosrFastPaxos_node1'),
'coordinator':
self.is_coordinator
}))
def _handle_read(self, msg_body):
key = msg_body['key']
if key in self.database:
launcher = SqsLauncher(self.coordinator_address)
launcher.launch_message({
'command': 'read_result',
'id': msg_body['id'],
'key': key,
'value': self.database[key]
})
def _start_listening(self):
# TODO consider incorporating output processing from here: https://github.com/debrouwere/sqs-antenna/blob/master/antenna/__init__.py
while True:
messages = self._client.receive_message(
QueueUrl=self._queue_url
)
if 'Messages' in messages:
print str(len(messages['Messages'])) + " messages received"
for m in messages['Messages']:
receipt_handle = m['ReceiptHandle']
m_body = m['Body']
message_attribs = None
attribs = None
# catch problems with malformed JSON, usually a result of someone writing poor JSON directly in the AWS console
try:
params_dict = json.loads(m_body)
except:
continue
if 'MessageAttributes' in m:
message_attribs = m['MessageAttributes']
if 'Attributes' in m:
attribs = m['Attributes']
try:
if self._force_delete:
self._client.delete_message(
QueueUrl=self._queue_url,
ReceiptHandle=receipt_handle
)
self.handle_message(params_dict, message_attribs, attribs)
else:
self.handle_message(params_dict, message_attribs, attribs)
self._client.delete_message(
QueueUrl=self._queue_url,
ReceiptHandle=receipt_handle
)
except Exception, ex:
print repr(ex)
if self._error_queue_name:
exc_type, exc_obj, exc_tb = sys.exc_info()
print "Pushing exception to error queue"
error_launcher = SqsLauncher(self._error_queue_name, True)
error_launcher.launch_message(
{
'exception_type': str(exc_type),
'error_message': str(ex.args)
}
)
else:
time.sleep(self._poll_interval)
def get_sqs(node):
return SqsLauncher(node)