GPS data storage system – Mysql

I have a python script written using twisted module which is running on an ubuntu server as a service.
We have many gps devices which sends data every 10 sec. My job is to parse that data and store it in database.
Everything is working fine, but total number of concurrent connections is somehow limited to 1012 on my server. I don’t know if it is servers fault or my script.
Plz enlighten me, Is running python script as a service a good practice?or it should run by some other means and why my connections are limited to the wired number 1012.

python script:-

#!/usr/bin/python3

class Message:
    """Parse message and save it in database"""

class Echo(Protocol):
    def connectionMade(self):
        factory_obj.c += 1

    def dataReceived(self, data):
        try:
            msg = data.decode('utf-8')
        except UnicodeDecodeError:
            pass
        else:
            message_handler.handle_message(msg)
            self.transport.write(data)

    def connectionLost(self, reason):
        factory_obj.c -= 1


class EchoFactory(Factory):
    def __init__(self):
        self.c = 0

    def buildProtocol(self, addr):
        return Echo()


class Db:
    """handles database"""


factory_obj = EchoFactory()
message_handler = Message()
database_obj = Db()
a = TCP4ServerEndpoint(reactor, 4995, interface='0.0.0.0', backlog=100000)
a.listen(factory_obj)
reactor.run()

I think my script is correct, there is some problem with server configuration, although I have tried many things like playing with ulimits and all, nothing worked.
Help me on this please.

Thanks!!