why my XMPP client resend messages? - python-2.7

Question

i have a XMPP cliente on heroku and it works with Google Cloud Messaging but i have a bad behavior on my app
i have cheked my code many times but i have not found any mistake, but some messages is been resent,the problem is not for Acknowledging of my messages, because i am Acknowledging each message and i am not receiving any nack message from GCM server, so i can not know what is the problem
i would appreciate for any help
this is my code
SERVER = 'gcm.googleapis.com'
PORT = 5235
USERNAME = "secret"
PASSWORD = "secret"
N_TIMER=40
EXP_TIMER=1
unacked_messages_quota = 100
send_queue = []
error_send_queue = []
lock=threading.Lock()
def unique_id():
return str(uuid.uuid4().hex)
#synchronized
def message_callback(session, message):
global unacked_messages_quota
gcm = message.getTags('gcm')
if gcm:
gcm_json = gcm[0].getData()
msg = json.loads(gcm_json)
if not msg.has_key('message_type'):
# Acknowledge the incoming message immediately.
send({'to': msg['from'],
'message_type': 'ack',
'message_id': msg['message_id']})
# Queue a response back to the server.
if msg.has_key('from'):
# Send a response back to the app that sent the upstream message.
try:
msg['data']['idCel'] = msg['from']
payloadObj= payload("command", msg['data']['command'] , msg['data'])
rpc = RpcClient()
response = rpc.call(payloadObj)
if 'response' in response and response['response'] == 'ok':
pass
elif response['type'] == 'response' :
send_queue.append({'to': msg['from'],
'priority':'high',
'delay_while_idle':True,
'message_id': unique_id(),
'data': {'response': response['response'],'type': 'response'}
})
else:
send_queue.append({'to': msg['from'],
'message_id': unique_id(),
'data': {'error': response['error'],'type': 'error'}})
except Exception as e:
traceback.print_exc()
print str(e)
elif msg['message_type'] == 'ack' or msg['message_type'] == 'nack':
if msg['message_type'] == 'nack':
error_send_queue.append(
{'to': msg['from'],
'message_type': 'ack',
'message_id': msg['message_id']})
unacked_messages_quota += 1
def send(json_dict):
template = ("<message><gcm xmlns='google:mobile:data'>{1}</gcm></message>")
try:
client.send(xmpp.protocol.Message(
node=template.format(client.Bind.bound[0], json.dumps(json_dict))))
except Exception as e:
traceback.print_exc()
print str(e)
def flush_queued_messages():
global unacked_messages_quota
while len(send_queue) and unacked_messages_quota > 0:
send(send_queue.pop(0))
unacked_messages_quota -= 1
def flush_queued_errors_messages():
lock.acquire()
global unacked_messages_quota
global error_send_queue
global EXP_TIMER
while len(error_send_queue) and unacked_messages_quota > 0:
send(error_send_queue.pop(0))
unacked_messages_quota -= 1
time.sleep( (2**EXP_TIMER) )
EXP_TIMER += 1
EXP_TIMER=1
lock.release()
client = xmpp.Client('gcm.googleapis.com',debug=['always', 'roster'],
port=int(os.environ.get("PORT")))
client.connect(server=(SERVER,PORT), secure=1, use_srv=False)
auth = client.auth(USERNAME, PASSWORD)
if not auth:
print 'Authentication failed!'
sys.exit(1)
client.RegisterHandler('message', message_callback)
t1 = threading.Thread(target=flush_queued_errors_messages)
while True:
client.Process(1)
flush_queued_messages()
if N_TIMER == 0:
client.send(" ")
N_TIMER = 40
if not t1.isAlive():
t1 = threading.Thread(target=flush_queued_errors_messages)
t1.start()
N_TIMER -= 1

Answer 1

I could know my real problem, the problem was not from my code but the problem was from GCM servers.
Here is the explication.