emit is not working when first client connect on connection handler from socket server.

[neerajdlh74]

In my code, i need to emit in the connection handler which is not working for first client and when I am connecting the second client it is start to work.
I checked many time, when I am starting the server and connecting the very first client that first emit from server's connect handler is not working.

below is the code i have removed all the remaining logic for quick reading.

server.py file is to run the gevent socket server:

import gevent.monkey
gevent.monkey.patch_all()
import socketio
from gevent import pywsgi
from geventwebsocket.handler import WebSocketHandler

url=['kafka://0.0.0.0:9092', 'kafka://0.0.0.1:9092', 'kafka://0.0.0.3:9092']
mgr = socketio.KafkaManager(url=url, channel='socket.service')

sio = socketio.Server(async_mode='gevent',client_manager=mgr,always_connect=True, logger=True, engineio_logger=True)
app = socketio.WSGIApp(sio)

class MyCustomNamespace(socketio.Namespace):

    def on_connect(self, sid, environ):
        """connecting player to the socket service"""
        print("player connected")
        self.emit("message", "message from socket", room=sid)

    def on_message(self, sid, data):
        """receive message from client"""
        pass

    def on_disconnect(self, sid):
        pass
        
sio.register_namespace(MyCustomNamespace('/test'))

if __name__ == '__main__':
    pywsgi.WSGIServer(('0.0.0.0', 61432), app, handler_class=WebSocketHandler)

client.py file to connect the client to the socket.

import asyncio
import socketio

class Check:
    def __init__(self):
        """initializing Asynchronous socket client object and namespaces"""
        self.sio = socketio.AsyncClient(handle_sigint=True, logger=True, engineio_logger=True)
        self.sio.on('connect', self.connect, namespace='/test')
        self.sio.on('message', self.message, namespace='/test')
        self.sio.on('disconnect', self.disconnect, namespace='/test')

       


    async def main_connect(self):
        """send connection request to socket server"""
        await self.sio.connect('http://0.0.0.0:61433', wait_timeout = 50, namespaces=['/test'])


    async def connect(self):
        """connect player to the socket service"""
        await self.sio.emit('message','hello', namespace= '/test')


    async def message(self, data):
        """receive message from socket server"""
        pass

    async def disconnect(self):
        """handle disconnection for player"""
        pass

    async def run(self):
        await self.main_connect()

async def main():
    """main method to connect player asynchronously"""
    async def loop(i):

        #sleep between player connection
        await asyncio.sleep(i/2)
        obj1 = Check()

        #launching run method to connect player
        await obj1.run()

        #waiting for connection to complete
        await obj1.sio.wait()

    #group multiple awaitables connection together
    x = [loop(i) for i in range(1)]
    await asyncio.gather(*x)
if __name__ == '__main__':
    """ executing asynchronous code """
    #event loop is needed to execute asynchronous code
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)

    #run the event loop until a future is done
    loop.run_until_complete(main())

this are the logs from client side. i have connected with 2 clients.. but receiving the packet from server only once as highlighted. 

Attempting polling connection to http://0.0.0.0:61432/socket.io/game/1/websocket/390751295781/?socket_qa2=True&table_id=1966&target=table&server_id=server:in1c1:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4
Polling connection accepted with {'sid': 'xV0RZkiQ77SImPoJAAAA', 'upgrades': ['websocket'], 'pingTimeout': 20000, 'pingInterval': 25000}Engine.IO connection establishedSending packet MESSAGE data 0/test,{}Attempting WebSocket upgrade to ws://0.0.0.0:61432/socket.io/game/1/websocket/390751295781/?socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:in1c1vircoz005.ivycomptech.co.in:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=websocket&EIO=4WebSocket upgrade was successfulReceived packet NOOP dataReceived packet MESSAGE data 0/test,{"sid":"6MJPbYmidSe0cy0LAAAB"}Namespace /test is connectedEmitting event "message" [/test]Sending packet MESSAGE data 2/test,["message","hello"]Attempting polling connection to http://0.0.0.0:61432/socket.io/game/1/websocket/390751295781/?socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4
Polling connection accepted with {'sid': '7H6i1sr5mj_RB_0yAAAC', 'upgrades': ['websocket'], 'pingTimeout': 20000, 'pingInterval': 25000}Engine.IO connection establishedSending packet MESSAGE data 0/test,{}
Attempting WebSocket upgrade to ws://0.0.0.0:61432/socket.io/game/1/websocket/390751295781/?socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:in1c1vircoz005.ivycomptech.co.in:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=websocket&EIO=4
WebSocket upgrade was successful
Received packet NOOP data
Received packet MESSAGE data 0/test,{"sid":"kRJk9LLkHJ3rYCV0AAAD"}
Namespace /test is connected
Emitting event "message" [/test]
Sending packet MESSAGE data 2/test,["message","hello"]
**Received packet MESSAGE data 2/test,["message","hello- message from socket"]**
Received event "message" [/test]hello- message from socket

below are the logs from server.py side.

- INFO   :__main__            : 27:  merge config successful
- DEBUG  :geventwebsocket.handler: 68:  Initializing WebSocketDEBUG  :
- geventwebsocket.handler:100:  Validating WebSocket requestINFO   :
- geventwebsocket.handler:242:  127.0.0.1 - - [2023-02-17 18:48:05] "GET /socket.io/game/1/websocket/390751295781/?socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4&t=1676659685.6840706 HTTP/1.1" 200 254 0.001082
- DEBUG  :geventwebsocket.handler: 68:  Initializing WebSocketDEBUG  :geventwebsocket.handler:100:  Validating WebSocket requestDEBUG  :geventwebsocket.handler:151:  Attempting to upgrade connectionDEBUG  :geventwebsocket.handler:230:  WebSocket request accepted, switching protocolsINFO   :socket_server.server13: 56:  client connected sid is 6MJPbYmidSe0cy0LAAAB, username-puzzledThrush2 and environ is  {'GATEWAY_INTERFACE': 'CGI/1.1', 'SERVER_SOFTWARE': 'gevent/1.5 Python/3.6', 'SCRIPT_NAME': '', 'wsgi.version': (1, 0), 'wsgi.multithread': False, 'wsgi.multiprocess': False, 'wsgi.run_once': False, 'wsgi.url_scheme': 'http', 'wsgi.errors': <_io.TextIOWrapper name='<stderr>' mode='w' encoding='UTF-8'>, 'SERVER_NAME': '', 'SERVER_PORT': '61432', 'REQUEST_METHOD': 'GET', 'PATH_INFO': '/socket.io/game/1/websocket/390751295781/', 'QUERY_STRING': 'socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4&t=1676659685.6840706', 'SERVER_PROTOCOL': 'HTTP/1.1', 'REMOTE_ADDR': '127.0.0.1', 'REMOTE_PORT': '54294', 'HTTP_HOST': '0.0.0.0:61432', 'HTTP_X_USERNAME': 'puzzledThrush2', 'HTTP_NICKNAME': 'cat', 'HTTP_ACCEPT': '*/*', 'HTTP_ACCEPT_ENCODING': 'gzip, deflate', 'HTTP_USER_AGENT': 'Python/3.6 aiohttp/3.8.1', 'wsgi.input': <gevent.pywsgi.Input object at 0x7f79b26cbe28>, 'wsgi.input_terminated': True}DEBUG  :geventwebsocket.handler: 68:  Initializing WebSocketDEBUG  :geventwebsocket.handler:100:  Validating WebSocket requestINFO   :geventwebsocket.handler:242:  127.0.0.1 - - [2023-02-17 18:48:06] "GET /socket.io/game/1/websocket/390751295781/?socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4&t=1676659686.185542 HTTP/1.1" 200 254 0.001518DEBUG  :geventwebsocket.handler: 68:  Initializing WebSocketDEBUG  :geventwebsocket.handler:100:  Validating WebSocket requestDEBUG  :geventwebsocket.handler:151:  Attempting to upgrade connectionDEBUG  :geventwebsocket.handler:230:  WebSocket request accepted, switching protocolsINFO   :socket_server.server13: 56:  client connected sid is kRJk9LLkHJ3rYCV0AAAD, username-gutturalMeerkat6 and environ is  {'GATEWAY_INTERFACE': 'CGI/1.1', 'SERVER_SOFTWARE': 'gevent/1.5 Python/3.6', 'SCRIPT_NAME': '', 'wsgi.version': (1, 0), 'wsgi.multithread': False, 'wsgi.multiprocess': False, 'wsgi.run_once': False, 'wsgi.url_scheme': 'http', 'wsgi.errors': <_io.TextIOWrapper name='<stderr>' mode='w' encoding='UTF-8'>, 'SERVER_NAME': '', 'SERVER_PORT': '61432', 'REQUEST_METHOD': 'GET', 'PATH_INFO': '/socket.io/game/1/websocket/390751295781/', 'QUERY_STRING': 'socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:in1c1vircoz005.redk.co.in:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4&t=1676659686.185542', 'SERVER_PROTOCOL': 'HTTP/1.1', 'REMOTE_ADDR': '127.0.0.1', 'REMOTE_PORT': '54310', 'HTTP_HOST': '0.0.0.0:61432', 'HTTP_X_USERNAME': 'gutturalMeerkat6', 'HTTP_NICKNAME': 'cat', 'HTTP_ACCEPT': '*/*', 'HTTP_ACCEPT_ENCODING': 'gzip, deflate', 'HTTP_USER_AGENT': 'Python/3.6 aiohttp/3.8.1', 'wsgi.input': <gevent.pywsgi.Input object at 0x7f79b261b468>, 'wsgi.input_terminated': True}INFO   :socket_server.keil  : 54:  message produced from socket to game server: {'GATEWAY_INTERFACE': 'CGI/1.1', 'SERVER_SOFTWARE': 'gevent/1.5 Python/3.6', 'SCRIPT_NAME': '', 'wsgi.version': (1, 0), 'wsgi.multithread': False, 'wsgi.multiprocess': False, 'wsgi.run_once': False, 'wsgi.url_scheme': 'http', 'SERVER_NAME': 'in1s4xrzgf015.redk.co.in', 'SERVER_PORT': '61432', 'REQUEST_METHOD': 'GET', 'PATH_INFO': '/socket.io/game/1/websocket/390751295781/', 'QUERY_STRING': 'socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:in1c1vircoz005.redk.co.in:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4&t=1676659685.6840706', 'SERVER_PROTOCOL': 'HTTP/1.1', 'REMOTE_ADDR': '127.0.0.1', 'REMOTE_PORT': '54294', 'HTTP_HOST': '0.0.0.0:61432', 'HTTP_X_USERNAME': 'puzzledThrush2', 'HTTP_NICKNAME': 'cat', 'HTTP_ACCEPT': '*/*', 'HTTP_ACCEPT_ENCODING': 'gzip, deflate', 'HTTP_USER_AGENT': 'Python/3.6 aiohttp/3.8.1', 'wsgi.input_terminated': True, 'table_id': '1966', 'target': 'table', 'server_id': 'zeus-server:in1c1vircoz005.redk.co.in:11431', 'sid': '6MJPbYmidSe0cy0LAAAB', 'client_count': 1, 'user_name': 'puzzledThrush2'}INFO   :socket_server.server13:113:  message received from cleint-6MJPbYmidSe0cy0LAAAB: helloINFO   :socket_server.keil  : 54:  message produced from socket to game server: {'GATEWAY_INTERFACE': 'CGI/1.1', 'SERVER_SOFTWARE': 'gevent/1.5 Python/3.6', 'SCRIPT_NAME': '', 'wsgi.version': (1, 0), 'wsgi.multithread': False, 'wsgi.multiprocess': False, 'wsgi.run_once': False, 'wsgi.url_scheme': 'http', 'SERVER_NAME': 'in1s4xrzgf015.redk.co.in', 'SERVER_PORT': '61432', 'REQUEST_METHOD': 'GET', 'PATH_INFO': '/socket.io/game/1/websocket/390751295781/', 'QUERY_STRING': 'socket_qa2=True&table_id=1966&target=table&server_id=zeus-server:in1c1vircoz005.redk.co.in:11431&session_id=696fd828-b7b5-40f5-862a-0f8136c468ee&transport=polling&EIO=4&t=1676659686.185542', 'SERVER_PROTOCOL': 'HTTP/1.1', 'REMOTE_ADDR': '127.0.0.1', 'REMOTE_PORT': '54310', 'HTTP_HOST': '0.0.0.0:61432', 'HTTP_X_USERNAME': 'gutturalMeerkat6', 'HTTP_NICKNAME': 'cat', 'HTTP_ACCEPT': '*/*', 'HTTP_ACCEPT_ENCODING': 'gzip, deflate', 'HTTP_USER_AGENT': 'Python/3.6 aiohttp/3.8.1', 'wsgi.input_terminated': True, 'table_id': '1966', 'target': 'table', 'server_id': 'zeus-server:in1c1vircoz005.redk.co.in:11431', 'sid': 'kRJk9LLkHJ3rYCV0AAAD', 'client_count': 2, 'user_name': 'gutturalMeerkat6'}INFO   :socket_server.server13:113:  message received from cleint-kRJk9LLkHJ3rYCV0AAAD: hello

[miguelgrinberg]

Which emit is not working? You have two, one on each side. Also, please include a working and non-working log session so that we can see where the emit is missing.

[neerajdlh74]

self.emit("message", "message from socket", room=sid) ---> this emit is not working on server.py file when 1st client is connecting, working after i am connecting the 2nd client. And i have updated the discussion with server and client logs.

[miguelgrinberg]

Server logs do not have Socket.IO logging enabled. Also, does everything work if you remove the Kafka client manager?

[arun6894]

@miguelgrinberg , you are correct. It works when we remove the Kafka client manager. But we want to make use of the client manager

[miguelgrinberg]

Unfortunately I don't use Kafka, and the KafkaManager class that you are using is an external contribution. So I rely on users like you to ensure this class works correctly. If you are willing to debug the issue and figure out why some messages are dropped I'll be happy to accept a pull request with the fix.