zmq.error.ZMQError:使用造纸机对多个笔记本运行多处理时，地址已在使用中

Question

我正在使用造纸机库同时运行多个使用多处理的笔记本电脑

这发生在Docker容器中的Python 3.6.6、Red Hat 4.8.2-15上

但是，当我运行python脚本时，由于我收到以下错误，大约5%的笔记本无法立即工作（没有运行Jupyter笔记本单元）：

Traceback (most recent call last):
  File "/opt/conda/lib/python3.6/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/opt/conda/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/opt/conda/lib/python3.6/site-packages/ipykernel_launcher.py", line 16, in <module>
    app.launch_new_instance()
  File "/opt/conda/lib/python3.6/site-packages/traitlets/config/application.py", line 657, in launch_instance
    app.initialize(argv)
  File "<decorator-gen-124>", line 2, in initialize
  File "/opt/conda/lib/python3.6/site-packages/traitlets/config/application.py", line 87, in catch_config_error
    return method(app, *args, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/ipykernel/kernelapp.py", line 469, in initialize
    self.init_sockets()
  File "/opt/conda/lib/python3.6/site-packages/ipykernel/kernelapp.py", line 238, in init_sockets
    self.shell_port = self._bind_socket(self.shell_socket, self.shell_port)
  File "/opt/conda/lib/python3.6/site-packages/ipykernel/kernelapp.py", line 180, in _bind_socket
    s.bind("tcp://%s:%i" % (self.ip, port))
  File "zmq/backend/cython/socket.pyx", line 547, in zmq.backend.cython.socket.Socket.bind
  File "zmq/backend/cython/checkrc.pxd", line 25, in zmq.backend.cython.checkrc._check_rc
zmq.error.ZMQError: Address already in use

以及：

Traceback (most recent call last):
  File "/opt/conda/lib/python3.6/multiprocessing/process.py", line 258, in _bootstrap
    self.run()
  File "/opt/conda/lib/python3.6/multiprocessing/process.py", line 93, in run
    self._target(*self._args, **self._kwargs)
  File "main.py", line 77, in run_papermill
    pm.execute_notebook(notebook, output_path, parameters=config)
  File "/opt/conda/lib/python3.6/site-packages/papermill/execute.py", line 104, in execute_notebook
    **engine_kwargs
  File "/opt/conda/lib/python3.6/site-packages/papermill/engines.py", line 49, in execute_notebook_with_engine
    return self.get_engine(engine_name).execute_notebook(nb, kernel_name, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/papermill/engines.py", line 304, in execute_notebook
    nb = cls.execute_managed_notebook(nb_man, kernel_name, log_output=log_output, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/papermill/engines.py", line 372, in execute_managed_notebook
    preprocessor.preprocess(nb_man, safe_kwargs)
  File "/opt/conda/lib/python3.6/site-packages/papermill/preprocess.py", line 20, in preprocess
    with self.setup_preprocessor(nb_man.nb, resources, km=km):
  File "/opt/conda/lib/python3.6/contextlib.py", line 81, in __enter__
    return next(self.gen)
  File "/opt/conda/lib/python3.6/site-packages/nbconvert/preprocessors/execute.py", line 345, in setup_preprocessor
    self.km, self.kc = self.start_new_kernel(**kwargs)
  File "/opt/conda/lib/python3.6/site-packages/nbconvert/preprocessors/execute.py", line 296, in start_new_kernel
    kc.wait_for_ready(timeout=self.startup_timeout)
  File "/opt/conda/lib/python3.6/site-packages/jupyter_client/blocking/client.py", line 104, in wait_for_ready
    raise RuntimeError('Kernel died before replying to kernel_info')
RuntimeError: Kernel died before replying to kernel_info

请帮我解决这个问题，因为我已经在网上搜索了不同的解决方案，到目前为止，没有一个能解决我的问题

无论我同时运行的笔记本电脑数量或我的计算机上的内核数量如何，都会出现5%的错误率，这让我感到非常奇怪

我尝试过更改start方法并更新库，但没有效果

我的库的版本是：

papermill==1.2.1
ipython==7.14.0
jupyter-client==6.1.3

谢谢大家!

Answer 1

明确的问题归因指向ZeroMQ无法成功.bind()

我们需要一些讲共同语言的细节&；同步：

_{如果你从未与ZeroMQ合作过，
在深入了解更多细节之前，你可以先看看"ZeroMQ: Principles in less than Five Seconds"}

---

错误消息：zmq.error.ZMQError: Address already in use更容易解释。由于显而易见的原因，ZeroMQ AccessPoint-s可以自由地尝试.connect()到许多对应方，但是只有一个可以.bind()到特定传输类的地址目标

发生这种情况有三个潜在原因：

1）通过{ multiprocessing.Process | joblib.Parallel | Docker-wrapped | ... }-派生副本意外调用某些代码（不知道内部细节）
，每个复制副本都试图获取某个ZeroMQ传输类地址的所有权，由于明显的原因，在第一个复制成功后，任何尝试都将失败

2）一种相当致命的情况，某些“以前”运行的进程无法释放此类传输类特定地址以供进一步使用（请记住，ZeroMQ可能只是其他感兴趣的候选地址之一，这是一个配置管理缺陷），或者在这种情况下，以前的运行未能正常终止此类资源使用，留下一个Context()-实例仍在等待（在某些情况下，直到O/S重新启动）侦听某些内容，这将永远不会发生

3）模块软件设计中的一个非常糟糕的工程实践，不去处理记录在案的ZeroMQ APIEADDRINUSE错误/异常，而不是仅仅使整个马戏团崩溃（为此付出所有相关成本）

---

另一条错误消息：RuntimeError: Kernel died before replying to kernel_info与一个状态相关，笔记本的内核试图用它自己的组件（池对等方）建立所有内部连接等待的时间比配置的或硬编码的超时时间长，内核进程只是停止等待，并将自己抛出到您观察和报告的未经处理的异常中

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解决方案：

首先检查任何挂起的地址所有者，如果对此有疑问，请重新启动所有节点，然后验证在您自己的代码/{ multiprocessing.Process() | joblib.Parallel() | ... the likes }-调用中没有“隐藏”冲突尝试，分发后可能会尝试.bind()到同一目标上。如果这些步骤都不能解决您控制范围内的问题，请询问模块的使用支持，以分析并帮助您重构&；验证仍然冲突的用例