Client unexpectedly closed TCP connection

Question

I have a couple of tasks running as a service. To kick off the worker I use:

def SvcDoRun(self):
    logging.info('Starting {name} service ...'.format(name=self._svc_name_))
    os.chdir(INSTDIR) # so that proj worker can be found
    logging.info('cwd: ' + os.getcwd())

    self.ReportServiceStatus(win32service.SERVICE_RUNNING)

    command = '{celery_path} -A {proj_dir} worker -f "{log_path}" -l info --hostname=theService@%h'.format(
        celery_path='celery',
        proj_dir=PROJECTDIR,
        log_path=os.path.join(INSTDIR,'celery.log'))

    logging.info('command: ' + command)

    args = shlex.split(command)
    proc = subprocess.Popen(args)

    logging.info('pid: {pid}'.format(pid=proc.pid))

    self.timeout = 5000

    while True:
        rc = win32event.WaitForSingleObject(self.hWaitStop, self.timeout)
        if rc == win32event.WAIT_OBJECT_0:
            print 'Terminate'
            # stop signal encountered
            PROCESS_TERMINATE = 1
            handle = win32api.OpenProcess(PROCESS_TERMINATE, False, proc.pid)
            win32api.TerminateProcess(handle, -1)
            win32api.CloseHandle(handle)
            break

To kick off the python tasks as a service I use:

def SvcDoRun(self):
      import servicemanager
      servicemanager.LogMsg(servicemanager.EVENTLOG_INFORMATION_TYPE,servicemanager.PYS_SERVICE_STARTED,(self._svc_name_, ''))

  self.timeout = 640000    #640 seconds / 10 minutes (value is in milliseconds)
  # This is how long the service will wait to run / refresh itself (see script below)

  while 1:
     try:
        # Wait for service stop signal, if I timeout, loop again
        rc = win32event.WaitForSingleObject(self.hWaitStop, self.timeout)
        # Check to see if self.hWaitStop happened
        if rc == win32event.WAIT_OBJECT_0:
           # Stop signal encountered
           servicemanager.LogInfoMsg(self._svc_name_ + " - STOPPED!")  #For Event Log
           break
        else:
           #[actual service code between rests]
           try:
              file_path = "C:\framework\celery\celery.py"
              execfile(file_path)             #Execute the script

           except Exception as exc:
              traceback.print_exc(file=sys.stdout)
           #[actual service code between rests]
     except Exception as exc:
        traceback.print_exc(file=sys.stdout)

The 'celery.py' contains the call to those tasks as follow celery.py:

from __future__ import absolute_import, unicode_literals
from celery import Celery

app = Celery(include=[
             'framework.task1.tasks',
             'framework.task2.tasks',
             'framework.task3.tasks',
             'framework.task4.tasks'
             ])

app.config_from_object('config')

if __name__ == '__main__':
    app.start()

The problem I call a task 'python runTask1.py param1 param2 param3' but sometimes the task never executes then I send it again (or twice) and it works... Looking at the rabbitmq log file I saw:

=INFO REPORT==== 24-Jun-2017::00:57:37 ===
accepting AMQP connection <0.3846.0> (127.0.0.1:57753 -> 127.0.0.1:5672)

=INFO REPORT==== 24-Jun-2017::00:57:37 ===
connection <0.3846.0> (127.0.0.1:57753 -> 127.0.0.1:5672): user 'guest' authenticated and granted access to vhost '/'

=INFO REPORT==== 24-Jun-2017::00:58:08 ===
accepting AMQP connection <0.3871.0> (127.0.0.1:57821 -> 127.0.0.1:5672)

=INFO REPORT==== 24-Jun-2017::00:58:08 ===
connection <0.3871.0> (127.0.0.1:57821 -> 127.0.0.1:5672): user 'guest' authenticated and granted access to vhost '/'

=INFO REPORT==== 24-Jun-2017::01:10:49 ===
accepting AMQP connection <0.3940.0> (127.0.0.1:57861 -> 127.0.0.1:5672)

=INFO REPORT==== 24-Jun-2017::01:10:49 ===
connection <0.3940.0> (127.0.0.1:57861 -> 127.0.0.1:5672): user 'guest' authenticated and granted access to vhost '/'

=WARNING REPORT==== 24-Jun-2017::01:10:49 ===
closing AMQP connection <0.3940.0> (127.0.0.1:57861 -> 127.0.0.1:5672):
client unexpectedly closed TCP connection

Why sometimes it works and sometimes it does not?