"There is no current event loop in thread" when using Dash with XGBoost

Dash Python
1

I have put together a Dash application that has two callbacks which do the following, respectively

  1. Update raw data on a weekly schedule using a dcc.Interval component by extracting data from SQL and saving it into a Div for the other callback to use. This process usually takes a while so I designed the application to run this separately from the next callback.
  2. Run an XGBoost model on the data loaded from the Div.

However, I am getting the error “RuntimeError: There is no current event loop in thread ‘Thread-24’.”, which upon inspecting the traceback below, appears to be related to XGBoost’s multithreading.

Traceback (most recent call last):
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\tornado\ioloop.py", line 271, in current
    return IOLoop._ioloop_for_asyncio[loop]
KeyError: <_WindowsSelectorEventLoop running=False closed=False debug=False>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\xgboost\compat.py", line 181, in <module>
    from dask.distributed import Client, get_client
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\dask\distributed.py", line 3, in <module>
    from distributed import *
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\__init__.py", line 3, in <module>
    from .actor import Actor, ActorFuture
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\actor.py", line 6, in <module>
    from .client import Future, default_client
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\client.py", line 44, in <module>
    from .batched import BatchedSend
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\batched.py", line 8, in <module>
    from .core import CommClosedError
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\core.py", line 17, in <module>
    from .comm import (
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\comm\__init__.py", line 25, in <module>
    _register_transports()
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\comm\__init__.py", line 17, in _register_transports
    from . import tcp
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\comm\tcp.py", line 337, in <module>
    class BaseTCPConnector(Connector, RequireEncryptionMixin):
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\distributed\comm\tcp.py", line 339, in BaseTCPConnector
    _resolver = netutil.ExecutorResolver(close_executor=False, executor=_executor)
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\tornado\util.py", line 286, in __new__
    instance.initialize(*args, **init_kwargs)
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\tornado\netutil.py", line 422, in initialize
    self.io_loop = IOLoop.current()
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\tornado\ioloop.py", line 276, in current
    current = AsyncIOMainLoop(make_current=True)  # type: Optional[IOLoop]
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\tornado\util.py", line 286, in __new__
    instance.initialize(*args, **init_kwargs)
  File "C:\Users\VictorBlancada\Anaconda3\lib\site-packages\tornado\platform\asyncio.py", line 228, in initialize
    super(AsyncIOMainLoop, self).initialize(asyncio.get_event_loop(), **kwargs)
  File "C:\Users\VictorBlancada\Anaconda3\lib\asyncio\events.py", line 644, in get_event_loop
    % threading.current_thread().name)
RuntimeError: There is no current event loop in thread 'Thread-24'.

Has anyone else encountered this?

1 Like
2

I’m having the same problems here. Up!