lightning/pytorch_lightning/trainer/trainer.py

1154 lines
44 KiB
Python

import os
import sys
import warnings
import logging as log
from typing import Union, Optional, List, Dict, Tuple
import torch
import torch.distributed as dist
import torch.multiprocessing as mp
from torch.utils.data import DataLoader
from tqdm.auto import tqdm
from torch.optim.optimizer import Optimizer
from pytorch_lightning.callbacks import ModelCheckpoint, EarlyStopping
from pytorch_lightning.loggers import LightningLoggerBase
from pytorch_lightning.profiler.profiler import BaseProfiler
from pytorch_lightning.trainer.auto_mix_precision import TrainerAMPMixin
from pytorch_lightning.trainer.callback_config import TrainerCallbackConfigMixin
from pytorch_lightning.trainer.data_loading import TrainerDataLoadingMixin
from pytorch_lightning.trainer.distrib_data_parallel import TrainerDDPMixin
from pytorch_lightning.trainer.distrib_parts import (
TrainerDPMixin,
parse_gpu_ids,
determine_root_gpu_device
)
from pytorch_lightning.core.lightning import LightningModule
from pytorch_lightning.trainer.evaluation_loop import TrainerEvaluationLoopMixin
from pytorch_lightning.trainer.logging import TrainerLoggingMixin
from pytorch_lightning.trainer.model_hooks import TrainerModelHooksMixin
from pytorch_lightning.trainer.training_io import TrainerIOMixin
from pytorch_lightning.trainer.training_loop import TrainerTrainLoopMixin
from pytorch_lightning.trainer.training_tricks import TrainerTrainingTricksMixin
from pytorch_lightning.utilities.debugging import MisconfigurationException
from pytorch_lightning.profiler import Profiler, PassThroughProfiler
try:
from apex import amp
APEX_AVAILABLE = True
except ImportError:
APEX_AVAILABLE = False
try:
import torch_xla
import torch_xla.core.xla_model as xm
import torch_xla.distributed.xla_multiprocessing as xmp
XLA_AVAILABLE = True
except ImportError:
XLA_AVAILABLE = False
class Trainer(TrainerIOMixin,
TrainerDPMixin,
TrainerDDPMixin,
TrainerLoggingMixin,
TrainerModelHooksMixin,
TrainerTrainingTricksMixin,
TrainerDataLoadingMixin,
TrainerAMPMixin,
TrainerEvaluationLoopMixin,
TrainerTrainLoopMixin,
TrainerCallbackConfigMixin,
):
def __init__(
self,
logger: Union[LightningLoggerBase, bool] = True,
checkpoint_callback: Union[ModelCheckpoint, bool] = True,
early_stop_callback: Optional[Union[EarlyStopping, bool]] = None,
default_save_path: Optional[str] = None,
gradient_clip_val: float = 0,
gradient_clip=None, # backward compatible, todo: remove in v0.8.0
process_position: int = 0,
nb_gpu_nodes=None, # backward compatible, todo: remove in v0.8.0
num_nodes: int = 1,
gpus: Optional[Union[List[int], str, int]] = None,
num_tpu_cores: Optional[int] = None,
log_gpu_memory: Optional[str] = None,
show_progress_bar: bool = True,
overfit_pct: float = 0.0,
track_grad_norm: int = -1,
check_val_every_n_epoch: int = 1,
fast_dev_run: bool = False,
accumulate_grad_batches: Union[int, Dict[int, int]] = 1,
max_nb_epochs=None, # backward compatible, todo: remove in v0.8.0
min_nb_epochs=None, # backward compatible, todo: remove in v0.8.0
max_epochs: int = 1000,
min_epochs: int = 1,
max_steps: Optional[int] = None,
min_steps: Optional[int] = None,
train_percent_check: float = 1.0,
val_percent_check: float = 1.0,
test_percent_check: float = 1.0,
val_check_interval: Union[float] = 1.0,
log_save_interval: int = 100,
row_log_interval: int = 10,
add_row_log_interval=None, # backward compatible, todo: remove in v0.8.0
distributed_backend: Optional[str] = None,
use_amp=False, # backward compatible, todo: remove in v0.8.0
precision: int = 32,
print_nan_grads: bool = False,
weights_summary: str = 'full',
weights_save_path: Optional[str] = None,
amp_level: str = 'O1',
nb_sanity_val_steps=None, # backward compatible, todo: remove in v0.8.0
num_sanity_val_steps: int = 5,
truncated_bptt_steps: Optional[int] = None,
resume_from_checkpoint: Optional[str] = None,
profiler: Optional[BaseProfiler] = None,
):
r"""
Customize every aspect of training via flags
Args:
logger: Logger for experiment tracking.
Example::
from pytorch_lightning.loggers import TensorBoardLogger
# default logger used by trainer
logger = TensorBoardLogger(
save_dir=os.getcwd(),
version=self.slurm_job_id,
name='lightning_logs'
)
Trainer(logger=logger)
checkpoint_callback: Callback for checkpointing.
Example::
from pytorch_lightning.callbacks import ModelCheckpoint
# default used by the Trainer
checkpoint_callback = ModelCheckpoint(
filepath=os.getcwd(),
save_best_only=True,
verbose=True,
monitor='val_loss',
mode='min',
prefix=''
)
trainer = Trainer(checkpoint_callback=checkpoint_callback)
early_stop_callback: Callback for early stopping. If
set to ``True``, then the default callback monitoring ``'val_loss'`` is created.
Will raise an error if ``'val_loss'`` is not found.
If set to ``False``, then early stopping will be disabled.
If set to ``None``, then the default callback monitoring ``'val_loss'`` is created.
If ``'val_loss'`` is not found will work as if early stopping is disabled.
Default: ``None``.
Example::
from pytorch_lightning.callbacks import EarlyStopping
# default used by the Trainer
early_stop_callback = EarlyStopping(
monitor='val_loss',
patience=3,
strict=False,
verbose=False,
mode='min'
)
trainer = Trainer(early_stop_callback=early_stop_callback)
default_save_path: Default path for logs and weights when no logger/ckpt_callback passed
Example::
# default used by the Trainer
trainer = Trainer(default_save_path=os.getcwd())
gradient_clip_val: 0 means don't clip.
Example::
# default used by the Trainer
trainer = Trainer(gradient_clip_val=0.0)
gradient_clip:
.. warning: .. deprecated:: 0.5.0
Use `gradient_clip_val` instead. Will remove 0.8.0.
process_position: orders the tqdm bar when running multiple models on same machine.
Example::
# default used by the Trainer
trainer = Trainer(process_position=0)
num_nodes: number of GPU nodes for distributed training.
Example::
# default used by the Trainer
trainer = Trainer(num_nodes=1)
# to train on 8 nodes
trainer = Trainer(num_nodes=8)
nb_gpu_nodes:
..warning:: .. deprecated:: 0.5.0
Use `num_nodes` instead. Will remove 0.8.0.
gpus: Which GPUs to train on.
Example::
# default used by the Trainer (ie: train on CPU)
trainer = Trainer(gpus=None)
# int: train on 2 gpus
trainer = Trainer(gpus=2)
# list: train on GPUs 1, 4 (by bus ordering)
trainer = Trainer(gpus=[1, 4])
trainer = Trainer(gpus='1, 4') # equivalent
# -1: train on all gpus
trainer = Trainer(gpus=-1)
trainer = Trainer(gpus='-1') # equivalent
# combine with num_nodes to train on multiple GPUs across nodes
trainer = Trainer(gpus=2, num_nodes=4) # uses 8 gpus in total
num_tpu_cores: How many TPU cores to train on (1 or 8).
A single TPU v2 or v3 has 8 cores. A TPU pod has
up to 2048 cores. A slice of a POD means you get as many cores
as you request.
You MUST use DistributedDataSampler with your dataloader for this
to work. Your effective batch size is batch_size * total tpu cores.
This parameter can be either 1 or 8.
Example::
# your_trainer_file.py
# default used by the Trainer (ie: train on CPU)
trainer = Trainer(num_tpu_cores=None)
# int: train on a single core
trainer = Trainer(num_tpu_cores=1)
# int: train on all cores few cores
trainer = Trainer(num_tpu_cores=8)
# for 8+ cores must submit via xla script with
# a max of 8 cores specified. The XLA script
# will duplicate script onto each TPU in the POD
trainer = Trainer(num_tpu_cores=8)
# -1: train on all available TPUs
trainer = Trainer(num_tpu_cores=-1)
To train on more than 8 cores (ie: a POD),
submit this script using the xla_dist script.
Example::
$ python -m torch_xla.distributed.xla_dist
--tpu=$TPU_POD_NAME
--conda-env=torch-xla-nightly
--env=XLA_USE_BF16=1
-- python your_trainer_file.py
log_gpu_memory: None, 'min_max', 'all'. Might slow performance
because it uses the output of nvidia-smi.
Example::
# default used by the Trainer
trainer = Trainer(log_gpu_memory=None)
# log all the GPUs (on master node only)
trainer = Trainer(log_gpu_memory='all')
# log only the min and max memory on the master node
trainer = Trainer(log_gpu_memory='min_max')
show_progress_bar: If true shows tqdm progress bar
Example::
# default used by the Trainer
trainer = Trainer(show_progress_bar=True)
overfit_pct: uses this much data of all datasets.
Example::
# default used by the Trainer
trainer = Trainer(overfit_pct=0.0)
# use only 1% of the train, test, val datasets
trainer = Trainer(overfit_pct=0.01)
track_grad_norm: -1 no tracking. Otherwise tracks that norm
Example::
# default used by the Trainer
trainer = Trainer(track_grad_norm=-1)
# track the 2-norm
trainer = Trainer(track_grad_norm=2)
check_val_every_n_epoch: Check val every n train epochs.
Example::
# default used by the Trainer
trainer = Trainer(check_val_every_n_epoch=1)
# run val loop every 10 training epochs
trainer = Trainer(check_val_every_n_epoch=10)
fast_dev_run: runs 1 batch of train, test and val to find any bugs (ie: a sort of unit test).
Example::
# default used by the Trainer
trainer = Trainer(fast_dev_run=False)
# runs 1 train, val, test batch and program ends
trainer = Trainer(fast_dev_run=True)
accumulate_grad_batches: Accumulates grads every k batches or as set up in the dict.
Example::
# default used by the Trainer (no accumulation)
trainer = Trainer(accumulate_grad_batches=1)
# accumulate every 4 batches (effective batch size is batch*4)
trainer = Trainer(accumulate_grad_batches=4)
# no accumulation for epochs 1-4. accumulate 3 for epochs 5-10. accumulate 20 after that
trainer = Trainer(accumulate_grad_batches={5: 3, 10: 20})
max_epochs: Stop training once this number of epochs is reached.
Example::
# default used by the Trainer
trainer = Trainer(max_epochs=1000)
max_nb_epochs:
.. warning:: .. deprecated:: 0.5.0
Use `max_epochs` instead. Will remove 0.8.0.
min_epochs: Force training for at least these many epochs
Example::
# default used by the Trainer
trainer = Trainer(min_epochs=1)
min_nb_epochs:
.. warning:: .. deprecated:: 0.5.0
Use `min_nb_epochs` instead. Will remove 0.8.0.
max_steps: Stop training after this number of steps. Disabled by default (None).
Training will stop if max_steps or max_epochs have reached (earliest).
Example::
# Stop after 100 steps
trainer = Trainer(max_steps=100)
min_steps: Force training for at least these number of steps. Disabled by default (None).
Trainer will train model for at least min_steps or min_epochs (latest).
Example::
# Run at least for 100 steps (disable min_epochs)
trainer = Trainer(min_steps=100, min_epochs=0)
train_percent_check: How much of training dataset to check.
Useful when debugging or testing something that happens at the end of an epoch.
Example::
# default used by the Trainer
trainer = Trainer(train_percent_check=1.0)
# run through only 25% of the training set each epoch
trainer = Trainer(train_percent_check=0.25)
val_percent_check: How much of validation dataset to check.
Useful when debugging or testing something that happens at the end of an epoch.
Example::
# default used by the Trainer
trainer = Trainer(val_percent_check=1.0)
# run through only 25% of the validation set each epoch
trainer = Trainer(val_percent_check=0.25)
test_percent_check: How much of test dataset to check.
Useful when debugging or testing something that happens at the end of an epoch.
Example::
# default used by the Trainer
trainer = Trainer(test_percent_check=1.0)
# run through only 25% of the test set each epoch
trainer = Trainer(test_percent_check=0.25)
val_check_interval: How often within one training epoch to check the validation set
If float, % of tng epoch. If int, check every n batch
Example::
# default used by the Trainer
trainer = Trainer(val_check_interval=1.0)
# check validation set 4 times during a training epoch
trainer = Trainer(val_check_interval=0.25)
# check validation set every 1000 training batches
# use this when using iterableDataset and your dataset has no length
# (ie: production cases with streaming data)
trainer = Trainer(val_check_interval=1000)
log_save_interval: Writes logs to disk this often
Example::
# default used by the Trainer
trainer = Trainer(log_save_interval=100)
row_log_interval: How often to add logging rows (does not write to disk)
Example::
# default used by the Trainer
trainer = Trainer(row_log_interval=10)
add_row_log_interval:
.. warning:: .. deprecated:: 0.5.0
Use `row_log_interval` instead. Will remove 0.8.0.
distributed_backend: The distributed backend to use.
Options: 'dp', 'ddp', 'ddp2'.
Example::
# default used by the Trainer
trainer = Trainer(distributed_backend=None)
# dp = DataParallel (split a batch onto k gpus on same machine).
trainer = Trainer(gpus=2, distributed_backend='dp')
# ddp = DistributedDataParallel
# Each gpu trains by itself on a subset of the data.
# Gradients sync across all gpus and all machines.
trainer = Trainer(gpus=2, num_nodes=2, distributed_backend='ddp')
# ddp2 = DistributedDataParallel + dp
# behaves like dp on every node
# syncs gradients across nodes like ddp
# useful for things like increasing the number of negative samples
trainer = Trainer(gpus=2, num_nodes=2, distributed_backend='ddp2')
use_amp:
.. warning:: .. deprecated:: 0.6.1
Use `precision` instead. Will remove 0.8.0.
precision: Full precision (32), half precision (16).
Can be used on CPU, GPU or TPUs.
If used on TPU will use torch.bfloat16 but tensor printing
will still show torch.float32.
Example::
# default used by the Trainer
trainer = Trainer(precision=32)
# 16-bit precision
trainer = Trainer(precision=16)
# one day
trainer = Trainer(precision=8|4|2)
print_nan_grads: Prints gradients with nan values
Example::
# default used by the Trainer
trainer = Trainer(print_nan_grads=False)
weights_summary: Prints a summary of the weights when training begins.
Options: 'full', 'top', None.
Example::
# default used by the Trainer (ie: print all weights)
trainer = Trainer(weights_summary='full')
# print only the top level modules
trainer = Trainer(weights_summary='top')
# don't print a summary
trainer = Trainer(weights_summary=None)
weights_save_path: Where to save weights if specified.
Example::
# default used by the Trainer
trainer = Trainer(weights_save_path=os.getcwd())
# save to your custom path
trainer = Trainer(weights_save_path='my/path')
# if checkpoint callback used, then overrides the weights path
# **NOTE: this saves weights to some/path NOT my/path
checkpoint_callback = ModelCheckpoint(filepath='some/path')
trainer = Trainer(
checkpoint_callback=checkpoint_callback,
weights_save_path='my/path'
)
amp_level: The optimization level to use (O1, O2, etc...).
Check nvidia docs for level (https://nvidia.github.io/apex/amp.html#opt-levels)
Example::
# default used by the Trainer
trainer = Trainer(amp_level='O1')
num_sanity_val_steps: Sanity check runs n batches of val before starting the training routine.
This catches any bugs in your validation without having to wait for the first validation check.
The Trainer uses 5 steps by default. Turn it off or modify it here.
Example::
# default used by the Trainer
trainer = Trainer(num_sanity_val_steps=5)
# turn it off
trainer = Trainer(num_sanity_val_steps=0)
nb_sanity_val_steps:
.. warning:: .. deprecated:: 0.5.0
Use `num_sanity_val_steps` instead. Will remove 0.8.0.
truncated_bptt_steps: Truncated back prop breaks performs backprop every k steps of
a much longer sequence If this is enabled, your batches will automatically get truncated
and the trainer will apply Truncated Backprop to it. Make sure your batches have a sequence
dimension. (`Williams et al. "An efficient gradient-based algorithm for on-line training of
recurrent network trajectories."
<http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.56.7941&rep=rep1&type=pdf>`_)
Example::
# default used by the Trainer (ie: disabled)
trainer = Trainer(truncated_bptt_steps=None)
# backprop every 5 steps in a batch
trainer = Trainer(truncated_bptt_steps=5)
Lightning takes care to split your batch along the time-dimension.
.. note:: If you need to modify how the batch is split,
override :meth:`pytorch_lightning.core.LightningModule.tbptt_split_batch`.
.. note:: Using this feature requires updating your LightningModule's
:meth:`pytorch_lightning.core.LightningModule.training_step` to include a `hiddens` arg.
resume_from_checkpoint: To resume training from a specific checkpoint pass in the path here.k
Example::
# default used by the Trainer
trainer = Trainer(resume_from_checkpoint=None)
# resume from a specific checkpoint
trainer = Trainer(resume_from_checkpoint='some/path/to/my_checkpoint.ckpt')
profiler: To profile individual steps during training and assist in
identifying bottlenecks.
Example::
from pytorch_lightning.profiler import Profiler, AdvancedProfiler
# default used by the Trainer
trainer = Trainer(profiler=None)
# to profile standard training events
trainer = Trainer(profiler=True)
# equivalent to profiler=True
profiler = Profiler()
trainer = Trainer(profiler=profiler)
# advanced profiler for function-level stats
profiler = AdvancedProfiler()
trainer = Trainer(profiler=profiler)
.. warning:: Following arguments become deprecated and they will be removed in v0.8.0:
- `nb_sanity_val_steps`
"""
# Transfer params
# Backward compatibility
if nb_gpu_nodes is not None:
warnings.warn("`nb_gpu_nodes` has renamed to `num_nodes` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
if not num_nodes: # in case you did not set the proper value
num_nodes = nb_gpu_nodes
self.num_gpu_nodes = num_nodes
self.log_gpu_memory = log_gpu_memory
# Backward compatibility
if gradient_clip is not None:
warnings.warn("`gradient_clip` has renamed to `gradient_clip_val` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
if not gradient_clip_val: # in case you did not set the proper value
gradient_clip_val = gradient_clip
self.gradient_clip_val = gradient_clip_val
self.check_val_every_n_epoch = check_val_every_n_epoch
self.track_grad_norm = track_grad_norm
self.on_gpu = True if (gpus and torch.cuda.is_available()) else False
# tpu config
self.on_tpu = num_tpu_cores is not None
self.num_tpu_cores = num_tpu_cores
assert num_tpu_cores in [1, 8, None], 'num_tpu_cores can only be 1 or 8'
self.process_position = process_position
self.weights_summary = weights_summary
# Backward compatibility
if max_nb_epochs is not None:
warnings.warn("`max_nb_epochs` has renamed to `max_epochs` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
if not max_epochs: # in case you did not set the proper value
max_epochs = max_nb_epochs
self.max_epochs = max_epochs
# Backward compatibility
if min_nb_epochs is not None:
warnings.warn("`min_nb_epochs` has renamed to `min_epochs` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
if not min_epochs: # in case you did not set the proper value
min_epochs = min_nb_epochs
self.min_epochs = min_epochs
self.max_steps = max_steps
self.min_steps = min_steps
# Backward compatibility
if nb_sanity_val_steps is not None:
warnings.warn("`nb_sanity_val_steps` has renamed to `num_sanity_val_steps` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
if not num_sanity_val_steps: # in case you did not set the proper value
num_sanity_val_steps = nb_sanity_val_steps
self.num_sanity_val_steps = num_sanity_val_steps
self.print_nan_grads = print_nan_grads
self.truncated_bptt_steps = truncated_bptt_steps
self.resume_from_checkpoint = resume_from_checkpoint
self.shown_warnings = set()
self.fast_dev_run = fast_dev_run
if self.fast_dev_run:
self.num_sanity_val_steps = 1
self.max_epochs = 1
m = '''
Running in fast_dev_run mode: will run a full train,
val loop using a single batch
'''
log.info(m)
# set default save path if user didn't provide one
self.default_save_path = default_save_path
if self.default_save_path is None:
self.default_save_path = os.getcwd()
# training bookeeping
self.total_batch_idx = 0
self.running_loss = []
self.avg_loss = 0
self.batch_idx = 0
self.tqdm_metrics = {}
self.callback_metrics = {}
self.num_val_batches = 0
self.num_training_batches = 0
self.num_test_batches = 0
self.get_train_dataloader = None
self.get_test_dataloaders = None
self.get_val_dataloaders = None
self.is_iterable_train_dataloader = False
# training state
self.model = None
self.testing = False
self.disable_validation = False
self.lr_schedulers = []
self.optimizers = None
self.global_step = 0
self.current_epoch = 0
self.total_batches = 0
# configure logger
self.configure_logger(logger)
# configure profiler
if profiler is True:
profiler = Profiler()
self.profiler = profiler or PassThroughProfiler()
# configure early stop callback
# creates a default one if none passed in
self.configure_early_stopping(early_stop_callback)
self.reduce_lr_on_plateau_scheduler = None
# configure checkpoint callback
self.checkpoint_callback = checkpoint_callback
self.weights_save_path = weights_save_path
# accumulated grads
self.configure_accumulated_gradients(accumulate_grad_batches)
# allow int, string and gpu list
self.data_parallel_device_ids = parse_gpu_ids(gpus)
self.root_gpu = determine_root_gpu_device(self.data_parallel_device_ids)
# tpu state flags
self.use_tpu = False
self.tpu_local_core_rank = None
self.tpu_global_core_rank = None
# distributed backend choice
self.use_ddp = False
self.use_ddp2 = False
self.use_dp = False
self.single_gpu = False
self.distributed_backend = distributed_backend
self.set_distributed_mode(distributed_backend, num_nodes)
# override dist backend when using tpus
if self.on_tpu:
self.init_tpu()
self.current_tpu_idx = None
# init flags for SLURM+ddp to work
self.proc_rank = 0
self.world_size = 1
self.node_rank = 0
self.configure_slurm_ddp(num_nodes)
# nvidia setup
self.set_nvidia_flags(self.is_slurm_managing_tasks, self.data_parallel_device_ids)
# can't init progress bar here because starting a new process
# means the progress_bar won't survive pickling
self.show_progress_bar = show_progress_bar
# logging
self.log_save_interval = log_save_interval
self.val_check_interval = val_check_interval
# backward compatibility
if add_row_log_interval is not None:
warnings.warn("`add_row_log_interval` has renamed to `row_log_interval` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
if not row_log_interval: # in case you did not set the proper value
row_log_interval = add_row_log_interval
self.row_log_interval = row_log_interval
# how much of the data to use
self.determine_data_use_amount(train_percent_check, val_percent_check,
test_percent_check, overfit_pct)
# 16 bit mixed precision training using apex
self.amp_level = amp_level
self.precision = precision
if self.precision == 16:
use_amp = True
self.init_amp(use_amp)
@property
def slurm_job_id(self) -> int:
try:
job_id = os.environ['SLURM_JOB_ID']
job_id = int(job_id)
except Exception:
job_id = None
return job_id
def __parse_gpu_ids(self, gpus):
"""Parse GPUs id.
:param list|str|int gpus: input GPU ids
:return list(int):
"""
# if gpus = -1 then use all available devices
# otherwise, split the string using commas
if gpus is not None:
if isinstance(gpus, list):
gpus = gpus
elif isinstance(gpus, str):
if gpus == '-1':
gpus = list(range(0, torch.cuda.device_count()))
else:
gpus = [int(x.strip()) for x in gpus.split(',')]
elif isinstance(gpus, int):
gpus = gpus
else:
raise ValueError('`gpus` has to be a string, int or list of ints')
return gpus
def __set_root_gpu(self, gpus):
if gpus is None:
return None
# set root gpu
root_gpu = 0
if isinstance(gpus, list):
root_gpu = gpus[0]
return root_gpu
@property
def num_gpus(self) -> int:
gpus = self.data_parallel_device_ids
if gpus is None:
return 0
return len(gpus)
@property
def data_parallel(self) -> bool:
return self.use_dp or self.use_ddp or self.use_ddp2
@property
def training_tqdm_dict(self) -> dict:
"""Read-only for tqdm metrics.
:return:
"""
ref_model = self.model if not self.data_parallel else self.model.module
return dict(**ref_model.get_tqdm_dict(), **self.tqdm_metrics)
@property
def tng_tqdm_dic(self):
"""Read-only for tqdm metrics.
:return: dictionary
.. warning:: .. deprecated:: 0.5.0
Use `training_tqdm_dict` instead. Will remove 0.8.0.
"""
warnings.warn("`tng_tqdm_dic` has renamed to `training_tqdm_dict` since v0.5.0"
" and this method will be removed in v0.8.0", DeprecationWarning)
return self.training_tqdm_dict
# -----------------------------
# MODEL TRAINING
# -----------------------------
def fit(
self,
model: LightningModule,
train_dataloader: Optional[DataLoader] = None,
val_dataloader: Optional[DataLoader] = None,
test_dataloader: Optional[DataLoader] = None
):
r"""
Runs the full optimization routine.
Args:
model: Model to fit.
train_dataloader: A Pytorch
DataLoader with training samples. If the model has
a predefined train_dataloader method this will be skipped.
val_dataloader: Either a single
Pytorch Dataloader or a list of them, specifying validation samples.
If the model has a predefined val_dataloader method this will be skipped
test_dataloader: Either a single
Pytorch Dataloader or a list of them, specifying validation samples.
If the model has a predefined val_dataloader method this will be skipped
Example::
# Option 1,
# Define the train_dataloader(), test_dataloader() and val_dataloader() fxs
# in the lightningModule
# RECOMMENDED FOR MOST RESEARCH AND APPLICATIONS TO MAINTAIN READABILITY
trainer = Trainer()
model = LightningModule()
trainer.fit(model)
# Option 2
# in production cases we might want to pass different datasets to the same model
# Recommended for PRODUCTION SYSTEMS
train, val, test = DataLoader(...), DataLoader(...), DataLoader(...)
trainer = Trainer()
model = LightningModule()
trainer.fit(model, train_dataloader=train,
val_dataloader=val, test_dataloader=test)
# Option 1 & 2 can be mixed, for example the training set can be
# defined as part of the model, and validation/test can then be
# feed to .fit()
"""
# Update the dataloader attributes of the model with the ones supplied here,
# if they are not already defined in model
_set_dataloader(model, train_dataloader, 'train_dataloader')
_set_dataloader(model, val_dataloader, 'val_dataloader')
_set_dataloader(model, test_dataloader, 'test_dataloader')
# when using multi-node or DDP within a node start each module in a separate process
if self.use_ddp2:
task = int(os.environ['SLURM_LOCALID'])
self.ddp_train(task, model)
elif self.use_ddp:
if self.is_slurm_managing_tasks:
task = int(os.environ['SLURM_LOCALID'])
self.ddp_train(task, model)
else:
mp.spawn(self.ddp_train, nprocs=self.num_gpus, args=(model,))
# 1 gpu or dp option triggers training using DP module
# easier to avoid NCCL issues
elif self.use_dp:
self.dp_train(model)
elif self.single_gpu:
self.single_gpu_train(model)
elif self.use_tpu:
log.info(f'training on {self.num_tpu_cores} TPU cores')
# COLAB_GPU is an env var available by default in Colab environments.
start_method = 'fork' if os.getenv('COLAB_GPU') else 'spawn'
xmp.spawn(self.tpu_train, args=(model,), nprocs=self.num_tpu_cores, start_method=start_method)
# ON CPU
else:
# run through amp wrapper
if self.use_amp:
raise MisconfigurationException('amp + cpu is not supported. Please use a GPU option')
# CHOOSE OPTIMIZER
# allow for lr schedulers as well
self.optimizers, self.lr_schedulers = self.init_optimizers(model.configure_optimizers())
self.run_pretrain_routine(model)
# return 1 when finished
# used for testing or when we need to know that training succeeded
return 1
def init_optimizers(
self,
optimizers: Union[Optimizer, Tuple[List, List], List[Optimizer], Tuple[Optimizer]]
) -> Tuple[List, List]:
# single optimizer
if isinstance(optimizers, Optimizer):
return [optimizers], []
# two lists
if len(optimizers) == 2 and isinstance(optimizers[0], list):
optimizers, lr_schedulers = optimizers
lr_schedulers, self.reduce_lr_on_plateau_scheduler = self.configure_schedulers(lr_schedulers)
return optimizers, lr_schedulers
# single list or tuple
if isinstance(optimizers, (list, tuple)):
return optimizers, []
def configure_schedulers(self, schedulers: list):
for i, scheduler in enumerate(schedulers):
if isinstance(scheduler, torch.optim.lr_scheduler.ReduceLROnPlateau):
reduce_lr_on_plateau_scheduler = schedulers.pop(i)
return schedulers, reduce_lr_on_plateau_scheduler
return schedulers, None
def run_pretrain_routine(self, model: LightningModule):
"""Sanity check a few things before starting actual training.
Args:
model: The model to run sanity test on.
"""
ref_model = model
if self.data_parallel:
ref_model = model.module
# give model convenience properties
ref_model.trainer = self
# set local properties on the model
self.copy_trainer_model_properties(ref_model)
# link up experiment object
if self.logger is not None:
ref_model.logger = self.logger
# save exp to get started
if hasattr(ref_model, "hparams"):
self.logger.log_hyperparams(ref_model.hparams)
self.logger.save()
if self.use_ddp or self.use_ddp2:
dist.barrier()
# wait for all models to restore weights
if self.on_tpu and XLA_AVAILABLE:
# wait for all processes to catch up
torch_xla.core.xla_model.rendezvous()
# set up checkpoint callback
self.configure_checkpoint_callback()
# register auto-resubmit when on SLURM
self.register_slurm_signal_handlers()
# transfer data loaders from model
self.get_dataloaders(ref_model)
# print model summary
if self.proc_rank == 0 and self.weights_summary is not None:
if self.weights_summary in ['full', 'top']:
ref_model.summarize(mode=self.weights_summary)
else:
m = "weights_summary can be None, 'full' or 'top'"
raise MisconfigurationException(m)
# track model now.
# if cluster resets state, the model will update with the saved weights
self.model = model
# restore training and model before hpc call
self.restore_weights(model)
# when testing requested only run test and return
if self.testing:
self.run_evaluation(test=True)
return
# check if we should run validation during training
self.disable_validation = ((self.num_val_batches == 0 or
not self.is_overriden('validation_step')) and
not self.fast_dev_run)
# run tiny validation (if validation defined)
# to make sure program won't crash during val
ref_model.on_sanity_check_start()
ref_model.on_train_start()
if not self.disable_validation and self.num_sanity_val_steps > 0:
# init progress bars for validation sanity check
pbar = tqdm(desc='Validation sanity check',
total=self.num_sanity_val_steps * len(self.get_val_dataloaders()),
leave=False, position=2 * self.process_position,
disable=not self.show_progress_bar, dynamic_ncols=True)
self.main_progress_bar = pbar
# dummy validation progress bar
self.val_progress_bar = tqdm(disable=True)
eval_results = self.evaluate(model, self.get_val_dataloaders(),
self.num_sanity_val_steps, False)
_, _, _, callback_metrics, _ = self.process_output(eval_results)
# close progress bars
self.main_progress_bar.close()
self.val_progress_bar.close()
if self.enable_early_stop:
self.early_stop_callback.check_metrics(callback_metrics)
# init progress bar
pbar = tqdm(leave=True, position=2 * self.process_position,
disable=not self.show_progress_bar, dynamic_ncols=True,
file=sys.stdout)
self.main_progress_bar = pbar
# clear cache before training
if self.on_gpu:
torch.cuda.empty_cache()
# CORE TRAINING LOOP
self.train()
def test(self, model: Optional[LightningModule] = None):
r"""
Separates from fit to make sure you never run on your test set until you want to.
Args:
model: The model to test.
Example::
# Option 1
# run test after fitting
trainer = Trainer()
model = LightningModule()
trainer.fit()
trainer.test()
# Option 2
# run test from a loaded model
model = LightningModule.load_from_checkpoint('path/to/checkpoint.ckpt')
trainer = Trainer()
trainer.test(model)
"""
self.testing = True
if model is not None:
self.fit(model)
else:
self.run_evaluation(test=True)
def _set_dataloader(model, dataloader, attribute):
r'''
Check dataloaders passed to .fit() method if they are pytorch DataLoader
objects and whether or not we should overright the corresponding dataloader
in the model
Args:
model (LightningModule): The model to check
dataloader: If a pytorch dataloader (or a list of pytorch dataloaders)
is passed, it will be incorporate into the model as model.attribute.
If attribute alreay exist it will warn the userpass. If not a
dataloader will throw an error
attribute (str): The attribute to save the dataloader under
'''
# Check if attribute comes directly from base class or
# derived in user subclass
if LightningModule.__qualname__ in getattr(model, attribute).__qualname__:
# Val and test should be list of dataloaders
dataloader = dataloader if attribute == 'train_dataloader' or \
(attribute != 'train_dataloader' and isinstance(dataloader, list)) else [dataloader]
# Check we are given valid dataloaders
is_dataloader = isinstance(dataloader, torch.utils.data.DataLoader)
is_dataloader_list = isinstance(dataloader, list)
if is_dataloader_list:
valid_loaders = all(isinstance(d, torch.utils.data.DataLoader) for d in dataloader)
if is_dataloader or is_dataloader_list and valid_loaders:
# Overwrite abstract methods
dl = lambda: dataloader
dl.__name__ = attribute
setattr(model, attribute, dl)
elif dataloader and dataloader != [None]:
raise ValueError(f'`{attribute}` needs to be an instance of '
'`torch.utils.data.DataLoader` or a list of '
'DataLoaders, instead got %r`' % dataloader)
elif dataloader: # if default (None) is passed, do not warn the user
warnings.warn(f'Model has predefined `{attribute}`,'
f' will skip `{attribute}={dataloader}` passed to fit method.')