def _set_task_scheduler(self, model, dataloaders):
"""Set task scheduler for learning process"""
# TODO: add more task scheduler support
opt = Meta.config["learner_config"]["task_scheduler"]
if opt == "sequential":
self.task_scheduler = SequentialScheduler()
elif opt == "round_robin":
self.task_scheduler = RoundRobinScheduler()
else:
raise ValueError(f"Unrecognized task scheduler option '{opt}'")
def test_round_robin_scheduler(caplog):
"""Unit test of round robin scheduler"""
caplog.set_level(logging.INFO)
emmental.Meta.init()
# Set random seed seed
set_random_seed(2)
task1 = "task1"
x1 = np.random.rand(20, 2)
y1 = torch.from_numpy(np.random.rand(20))
task2 = "task2"
x2 = np.random.rand(30, 3)
y2 = torch.from_numpy(np.random.rand(30))
dataloaders = [
EmmentalDataLoader(
task_to_label_dict={task_name: "label"},
dataset=EmmentalDataset(name=task_name,
X_dict={"feature": x},
Y_dict={"label": y}),
split="train",
batch_size=10,
shuffle=True,
) for task_name, x, y in [(task1, x1, y1), (task2, x2, y2)]
]
scheduler = RoundRobinScheduler()
assert scheduler.get_num_batches(dataloaders) == 5
batch_task_names = [
batch_data[-2] for batch_data in scheduler.get_batches(dataloaders)
]
assert batch_task_names == [task2, task1, task2, task2, task1]
scheduler = RoundRobinScheduler(fillup=True)
assert scheduler.get_num_batches(dataloaders) == 6
batch_task_names = [
batch_data[-2] for batch_data in scheduler.get_batches(dataloaders)
]
assert batch_task_names == [task2, task1, task2, task2, task1, task1]
def test_round_robin_scheduler_no_y_dict(caplog):
"""Unit test of round robin scheduler with no y_dict."""
caplog.set_level(logging.INFO)
init()
# Set random seed seed
set_random_seed(2)
task1 = "task1"
x1 = np.random.rand(20, 2)
task2 = "task2"
x2 = np.random.rand(30, 3)
dataloaders = [
EmmentalDataLoader(
task_to_label_dict={task_name: None},
dataset=EmmentalDataset(name=task_name, X_dict={"feature": x}),
split="train",
batch_size=10,
shuffle=True,
) for task_name, x in [(task1, x1), (task2, x2)]
]
dataloaders[0].n_batches = 3
dataloaders[1].n_batches = 4
scheduler = RoundRobinScheduler()
assert scheduler.get_num_batches(dataloaders) == 7
batch_y_dicts = [
batch.Y_dict for batch in scheduler.get_batches(dataloaders)
]
assert batch_y_dicts == [None] * 7
class EmmentalLearner(object):
"""A class for emmental multi-task learning.
"""
def __init__(self, name=None):
self.name = name if name is not None else type(self).__name__
def _set_logging_manager(self):
"""Set logging manager."""
self.logging_manager = LoggingManager(self.n_batches_per_epoch)
def _set_optimizer(self, model):
"""Set optimizer for learning process."""
# TODO: add more optimizer support and fp16
optimizer_config = Meta.config["learner_config"]["optimizer_config"]
opt = optimizer_config["optimizer"]
parameters = filter(lambda p: p.requires_grad, model.parameters())
if opt == "sgd":
optimizer = optim.SGD(
parameters,
lr=optimizer_config["lr"],
**optimizer_config["sgd_config"],
weight_decay=optimizer_config["l2"],
)
elif opt == "adam":
optimizer = optim.Adam(
parameters,
lr=optimizer_config["lr"],
**optimizer_config["adam_config"],
weight_decay=optimizer_config["l2"],
)
elif opt == "adamax":
optimizer = optim.Adamax(
parameters,
lr=optimizer_config["lr"],
**optimizer_config["adamax_config"],
weight_decay=optimizer_config["l2"],
)
elif opt == "bert_adam":
optimizer = BertAdam(
parameters,
lr=optimizer_config["lr"],
**optimizer_config["bert_adam_config"],
weight_decay=optimizer_config["l2"],
)
else:
raise ValueError(f"Unrecognized optimizer option '{opt}'")
logger.info(f"Using optimizer {optimizer}")
self.optimizer = optimizer
def _set_lr_scheduler(self, model):
"""Set learning rate scheduler for learning process."""
# Set warmup scheduler
self._set_warmup_scheduler(model)
# Set lr scheduler
# TODO: add more lr scheduler support
opt = Meta.config["learner_config"]["lr_scheduler_config"][
"lr_scheduler"]
lr_scheduler_config = Meta.config["learner_config"][
"lr_scheduler_config"]
if opt is None:
lr_scheduler = None
elif opt == "linear":
total_steps = (self.n_batches_per_epoch *
Meta.config["learner_config"]["n_epochs"])
linear_decay_func = lambda x: (total_steps - self.warmup_steps - x
) / (total_steps - self.warmup_steps
)
lr_scheduler = optim.lr_scheduler.LambdaLR(self.optimizer,
linear_decay_func)
elif opt == "exponential":
lr_scheduler = optim.lr_scheduler.ExponentialLR(
self.optimizer, **lr_scheduler_config["exponential_config"])
elif opt == "step":
lr_scheduler = optim.lr_scheduler.StepLR(
self.optimizer, **lr_scheduler_config["step_config"])
elif opt == "multi_step":
lr_scheduler = optim.lr_scheduler.MultiStepLR(
self.optimizer, **lr_scheduler_config["multi_step_config"])
# elif opt == "reduce_on_plateau":
# lr_scheduler = optim.lr_scheduler.ReduceLROnPlateau(
# self.optimizer,
# min_lr=lr_scheduler_config["min_lr"],
# **lr_scheduler_config["plateau_config"],
# )
else:
raise ValueError(f"Unrecognized lr scheduler option '{opt}'")
self.lr_scheduler = lr_scheduler
def _set_warmup_scheduler(self, model):
"""Set warmup learning rate scheduler for learning process."""
if Meta.config["learner_config"]["lr_scheduler_config"][
"warmup_steps"]:
warmup_steps = Meta.config["learner_config"][
"lr_scheduler_config"]["warmup_steps"]
if warmup_steps < 0:
raise ValueError(f"warmup_steps much greater or equal than 0.")
warmup_unit = Meta.config["learner_config"]["lr_scheduler_config"][
"warmup_unit"]
if warmup_unit == "epoch":
self.warmup_steps = int(warmup_steps *
self.n_batches_per_epoch)
elif warmup_unit == "batch":
self.warmup_steps = int(warmup_steps)
else:
raise ValueError(
f"warmup_unit must be 'batch' or 'epoch', but {warmup_unit} found."
)
linear_warmup_func = lambda x: x / self.warmup_steps
warmup_scheduler = optim.lr_scheduler.LambdaLR(
self.optimizer, linear_warmup_func)
logger.info(f"Warmup {self.warmup_steps} batchs.")
elif Meta.config["learner_config"]["lr_scheduler_config"][
"warmup_percentage"]:
warmup_percentage = Meta.config["learner_config"][
"lr_scheduler_config"]["warmup_percentage"]
self.warmup_steps = int(warmup_percentage *
Meta.config["learner_config"]["n_epochs"] *
self.n_batches_per_epoch)
linear_warmup_func = lambda x: x / self.warmup_steps
warmup_scheduler = optim.lr_scheduler.LambdaLR(
self.optimizer, linear_warmup_func)
logger.info(f"Warmup {self.warmup_steps} batchs.")
else:
warmup_scheduler = None
self.warmup_steps = 0
self.warmup_scheduler = warmup_scheduler
def _update_lr_scheduler(self, model, step):
"""Update the lr using lr_scheduler with each batch."""
if self.warmup_scheduler and step < self.warmup_steps:
self.warmup_scheduler.step()
elif self.lr_scheduler is not None:
self.lr_scheduler.step()
min_lr = Meta.config["learner_config"]["lr_scheduler_config"][
"min_lr"]
if min_lr and self.optimizer.param_groups[0]["lr"] < min_lr:
self.optimizer.param_groups[0]["lr"] = min_lr
def _set_task_scheduler(self, model, dataloaders):
"""Set task scheduler for learning process"""
# TODO: add more task scheduler support
opt = Meta.config["learner_config"]["task_scheduler"]
if opt == "sequential":
self.task_scheduler = SequentialScheduler()
elif opt == "round_robin":
self.task_scheduler = RoundRobinScheduler()
else:
raise ValueError(f"Unrecognized task scheduler option '{opt}'")
def _evaluate(self, model, dataloaders, split):
if not isinstance(split, list):
valid_split = [split]
else:
valid_split = split
valid_dataloaders = [
dataloader for dataloader in dataloaders
if dataloader.split in valid_split
]
return model.score(valid_dataloaders)
def _logging(self, model, dataloaders, batch_size):
"""Checking if it's time to evaluting or checkpointing"""
# Switch to eval mode for evaluation
model.eval()
metric_dict = dict()
self.logging_manager.update(batch_size)
# Log the loss and lr
metric_dict.update(self._aggregate_losses())
# Evaluate the model and log the metric
if self.logging_manager.trigger_evaluation():
# Log task specific metric
metric_dict.update(
self._evaluate(model, dataloaders,
Meta.config["learner_config"]["valid_split"]))
self.logging_manager.write_log(metric_dict)
self._reset_losses()
# Checkpoint the model
if self.logging_manager.trigger_checkpointing():
self.logging_manager.checkpoint_model(model, self.optimizer,
self.lr_scheduler,
metric_dict)
self.logging_manager.write_log(metric_dict)
self._reset_losses()
# Switch to train mode
model.train()
return metric_dict
def _aggregate_losses(self):
"""Calculate the task specific loss, average micro loss and learning rate."""
metric_dict = dict()
# Log task specific loss
for identifier in self.running_losses.keys():
if self.running_counts[identifier] > 0:
metric_dict[identifier] = (self.running_losses[identifier] /
self.running_counts[identifier])
# Calculate average micro loss
total_loss = sum(self.running_losses.values())
total_count = sum(self.running_counts.values())
if total_count > 0:
metric_dict["model/train/all/loss"] = total_loss / total_count
# Log the learning rate
metric_dict["model/train/all/lr"] = self.optimizer.param_groups[0][
"lr"]
return metric_dict
def _reset_losses(self):
self.running_losses = defaultdict(float)
self.running_counts = defaultdict(int)
def learn(self, model, dataloaders):
"""The learning procedure of emmental MTL
:param model: The emmental model that needs to learn
:type model: emmental.model
:param dataloaders: a list of dataloaders used to learn the model
:type dataloaders: list
"""
# Generate the list of dataloaders for learning process
train_split = Meta.config["learner_config"]["train_split"]
if isinstance(train_split, str):
train_split = [train_split]
train_dataloaders = [
dataloader for dataloader in dataloaders
if dataloader.split in train_split
]
if not train_dataloaders:
raise ValueError(
f"Cannot find the specified train_split "
f'{Meta.config["learner_config"]["train_split"]} in dataloaders.'
)
# Calculate the total number of batches per epoch
self.n_batches_per_epoch = sum(
[len(dataloader) for dataloader in train_dataloaders])
# Set up logging manager
self._set_logging_manager()
# Set up optimizer
self._set_optimizer(model)
# Set up lr_scheduler
self._set_lr_scheduler(model)
# Set up task_scheduler
self._set_task_scheduler(model, dataloaders)
# Set to training mode
model.train()
logger.info(f"Start learning...")
self.metrics = dict()
self._reset_losses()
for epoch_num in range(Meta.config["learner_config"]["n_epochs"]):
batches = tqdm(
enumerate(self.task_scheduler.get_batches(train_dataloaders)),
total=self.n_batches_per_epoch,
disable=(not Meta.config["meta_config"]["verbose"]),
desc=f"Epoch {epoch_num}:",
)
for batch_num, (batch, task_to_label_dict, data_name,
split) in batches:
X_dict, Y_dict = batch
total_batch_num = epoch_num * self.n_batches_per_epoch + batch_num
batch_size = len(next(iter(Y_dict.values())))
# Update lr using lr scheduler
self._update_lr_scheduler(model, total_batch_num)
# Set gradients of all model parameters to zero
self.optimizer.zero_grad()
# Perform forward pass and calcualte the loss and count
loss_dict, count_dict = model.calculate_loss(
X_dict, Y_dict, task_to_label_dict, data_name, split)
# Update running loss and count
for identifier in loss_dict.keys():
self.running_losses[identifier] += (
loss_dict[identifier].item() * count_dict[identifier])
self.running_counts[identifier] += count_dict[identifier]
# Skip the backward pass if no loss is calcuated
if not loss_dict:
continue
# Calculate the average loss
loss = sum(loss_dict.values())
# Perform backward pass to calculate gradients
loss.backward()
# Clip gradient norm
if Meta.config["learner_config"]["optimizer_config"][
"grad_clip"]:
torch.nn.utils.clip_grad_norm_(
model.parameters(),
Meta.config["learner_config"]["optimizer_config"]
["grad_clip"],
)
# Update the parameters
self.optimizer.step()
self.metrics.update(
self._logging(model, dataloaders, batch_size))
batches.set_postfix(self.metrics)
model = self.logging_manager.close(model)