44 lines
1.3 KiB
ReStructuredText
44 lines
1.3 KiB
ReStructuredText
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:orphan:
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.. _debugging_advanced:
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###########################
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Debug your model (advanced)
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###########################
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**Audience**: Users who want to debug distributed models.
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----
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************************
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Debug distributed models
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************************
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To debug a distributed model, we recommend you debug it locally by running the distributed version on CPUs:
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.. code-block:: python
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trainer = Trainer(accelerator="cpu", strategy="ddp", devices=2)
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On the CPU, you can use `pdb <https://docs.python.org/3/library/pdb.html>`_ or `breakpoint() <https://docs.python.org/3/library/functions.html#breakpoint>`_
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or use regular print statements.
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.. testcode::
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class LitModel(LightningModule):
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def training_step(self, batch, batch_idx):
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debugging_message = ...
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print(f"RANK - {self.trainer.global_rank}: {debugging_message}")
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if self.trainer.global_rank == 0:
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import pdb
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pdb.set_trace()
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# to prevent other processes from moving forward until all processes are in sync
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self.trainer.strategy.barrier()
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When everything works, switch back to GPU by changing only the accelerator.
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.. code-block:: python
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trainer = Trainer(accelerator="gpu", strategy="ddp", devices=2)
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