title: py4j.protocol.Py4JNetworkError: An error occurred while trying to connect to the Java server (127.0.0.1:25333)
body: <p>I was running a server within a docker container, the package and image were provided by others so I can't access the code but only the tar.gz package, and I have no idea what services this container is providing.</p>
  <p>It worked right several days ago and was not working since one restart, then I restarted it several times trying to get it to run, but it still has the same error. Is there any chance to make it run without touching the code since I cannot? Here is the error description:</p>
  <pre><code>P29 2022-05-25 10:59:24,923 INFO [lib_dataserver_exp.py:137] backend config: backend.conf
  P29 2022-05-25 10:59:25,046 INFO [data_server.py:134] starting helper: java -Xmx32g -Dmoqi.logfile=helper -jar /root/fm-package/backend/backend.jar -c /root/fm-package/backend/backend.conf helper
  Traceback (most recent call last):
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 958, in _get_connection
      connection = self.deque.pop()
  IndexError: pop from an empty deque
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 1096, in start
      self.socket.connect((self.address, self.port))
  ConnectionRefusedError: [Errno 111] Connection refused
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File &quot;/opt/conda/lib/python3.6/site-packages/fabric/main.py&quot;, line 763, in main
      *args, **kwargs
    File &quot;/opt/conda/lib/python3.6/site-packages/fabric/tasks.py&quot;, line 427, in execute
      results['&lt;local-only&gt;'] = task.run(*args, **new_kwargs)
    File &quot;/opt/conda/lib/python3.6/site-packages/fabric/tasks.py&quot;, line 174, in run
      return self.wrapped(*args, **kwargs)
    File &quot;/builds/fingerprint-core/fingerprint-matching/fm_lib/data_server/lib_dataserver_exp.py&quot;, line 151, in start_dataserver
    File &quot;/builds/fingerprint-core/fingerprint-matching/fm_lib/data_server/data_server.py&quot;, line 648, in __init__
    File &quot;/builds/fingerprint-core/fingerprint-matching/fm_lib/data_server/data_server.py&quot;, line 140, in __init__
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 1284, in __call__
      answer = self.gateway_client.send_command(command)
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 1012, in send_command
      connection = self._get_connection()
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 960, in _get_connection
      connection = self._create_connection()
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 966, in _create_connection
      connection.start()
    File &quot;/opt/conda/lib/python3.6/site-packages/py4j/java_gateway.py&quot;, line 1108, in start
      raise Py4JNetworkError(msg, e)
  py4j.protocol.Py4JNetworkError: An error occurred while trying to connect to the Java server (127.0.0.1:25333)
  failed to send log to fluentd
  </code></pre>