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import sys |
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import logging |
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|
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logger = logging.getLogger(__name__) |
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|
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_orig_except_hook = None |
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|
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def _global_except_hook(exctype, value, traceback): |
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"""Catches an unhandled exception and call MPI_Abort().""" |
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try: |
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if _orig_except_hook: |
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_orig_except_hook(exctype, value, traceback) |
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else: |
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sys.__excepthook__(exctype, value, traceback) |
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|
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finally: |
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import mpi4py.MPI |
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rank = mpi4py.MPI.COMM_WORLD.Get_rank() |
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logger.warning("******************************************") |
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logger.warning("MainzTrainer:") |
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logger.warning(f" Uncaught exception on rank {rank}.") |
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logger.warning(" Calling MPI_Abort() to shut down MPI...") |
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logger.warning("******************************************") |
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logging.shutdown() |
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|
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try: |
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import mpi4py.MPI |
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mpi4py.MPI.COMM_WORLD.Abort(1) |
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except Exception as e: |
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|
|
|
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sys.stderr.write("Sorry, failed to stop MPI and the process may hang.\n") |
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sys.stderr.flush() |
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raise e |
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|
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def add_hook(): |
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""" |
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Add a global hook function that captures all unhandled exceptions. |
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The function calls MPI_Abort() to force all processes abort. |
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|
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An MPI runtime is expected to kill all of its child processes |
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if one of them exits abnormally or without calling `MPI_Finalize()`. |
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However, when a Python program run on `mpi4py`, the MPI runtime |
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often fails to detect a process failure, and the rest of the processes |
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hang infinitely. |
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|
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See https://github.com/chainer/chainermn/issues/236 and |
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https://mpi4py.readthedocs.io/en/stable/mpi4py.run.html for more |
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information. |
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""" |
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global _orig_except_hook |
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|
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if _orig_except_hook is not None: |
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logger.warning("GlobalExceptHook.add_hook() seems to be called multiple times. Ignoring.") |
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return |
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|
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logger.info("Adding global except hook for the distributed job to shutdown MPI if unhandled exception is raised on some of the ranks.") |
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_orig_except_hook = sys.excepthook |
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sys.excepthook = _global_except_hook |
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|
