Getting rid of the clutter of `.lr_find_` in pytorch lightning? - pytorch

When using the Lightning’s built-in LR finder:
# Create a Tuner
tuner = Tuner(trainer)
# finds learning rate automatically
# sets hparams.lr or hparams.learning_rate to that learning rate
tuner.lr_find(model)
a lot of checkpoint lr_find_XXX.ckpt are created in the running directory which creates clutter. How can I make sure that these checkpoint are not created? Or keep them in a dedicated directory?

As it is defined in the lr_finder.py as:
# Save initial model, that is loaded after learning rate is found
ckpt_path = os.path.join(trainer.default_root_dir, f".lr_find_{uuid.uuid4()}.ckpt")
trainer.save_checkpoint(ckpt_path)
the initial model is saved with the checkpoint you are mentioning lr_find_XXX.ckpt to the directory trainer.default_root_dir. If no default directory is defined during the initialization of the trainer, current working directory will be assigned as the default_root_dir. After finding the ideal learning rate lr_find restores the initial model from the checkpoint and removes the checkpoint.
# Restore initial state of model
trainer._checkpoint_connector.restore(ckpt_path)
trainer.strategy.remove_checkpoint(ckpt_path)
You are probably stopping the program before the checkpoint is restored and removed so you have two options:
Wait for the ideal learning rate to be found so that the checkpoint is removed
Change the default_root_dir: Trainer(default_root_dir='./NAME_OF_THE_DIR') but be aware that this is also the directory that the lightning logs are saved to.

Related

How to retrain pytorch-lightning based model on new data using previous checkpoint

I'm using the pytorch-forecasting library (which is based on pytorch-lightning) for running a TFT model on time series forecasting. My training routine is segregated into three different tasks. At first I perform HPO using optuna, then I do a training+validation, and in the end, a retraining with full data (no validation).
Currently, both training+validation and retraining are happening using fresh models from scratch, so the runtime is quite high. So, I'm trying to reduce the run-time of the whole training routine by trying to leverage incremental-training where I'll load the checkpointed trained model from phase 2 and retrain it for smaller epochs on phase 3.
I have a method fit_model() which is used in both training/validation and retraining, but with different args. The core part of my fit() looks something like the following:
def fit_model(self, **kwargs):
...
to_retrain = kwargs.get('to_retrain', False)
ckpt_path = kwargs.get('ckpt_path', None)
trainer = self._get_trainer(cluster_id, gpu_id, to_retrain) # returns a pl.Trainer object
tft_lightning_module = self._prepare_for_training(cluster_id, to_retrain)
train_dtloaders = ...
val_dtloaders = ...
if not to_retrain:
trainer.fit(
tft_lightning_module,
train_dataloaders=train_dtloaders,
val_dataloaders=val_dtloaders
)
else:
trainer.fit(
tft_lightning_module,
train_dataloaders=train_dtloaders,
val_dataloaders=val_dtloaders,
ckpt_path=ckpt_path
)
best_model_path = trainer.checkpoint_callback.best_model_path
return best_model_path
While I call the above method in my retraining phase, I can see the log where it says that it's loading the checkpointed model:
Restored all states from the checkpoint file at /tft/incremental_training/tft_training_20230206/171049/lightning_logs_3/lightning_logs/version_0/checkpoints/epoch=4-step=5.ckpt
But unfortunately, no further training is happening at phase 3. If I look at the best_model_path returned by the method, it has the old checkpoint path from train/validation phase and not from retraining phase. How to resolve this issue?
I'm using the following libraries
pytorch-lightning==1.6.5
pytorch-forecasting==0.9.0
I got it working finally. The key thing to keep in mind here is not to use same number of epochs in both training and retraining. If we're training for x epochs and intend to run the retraining for y more epochs, then max-epochs has to be set to x+y and not y in retraining.

Submitting multiple runs to the same node on AzureML

I want to perform hyperparameter search using AzureML. My models are small (around 1GB) thus I would like to run multiple models on the same GPU/node to save costs but I do not know how to achieve this.
The way I currently submit jobs is the following (resulting in one training run per GPU/node):
experiment = Experiment(workspace, experiment_name)
config = ScriptRunConfig(source_directory="./src",
script="train.py",
compute_target="gpu_cluster",
environment="env_name",
arguments=["--args args"])
run = experiment.submit(config)
ScriptRunConfig can be provided with a distributed_job_config. I tried to use MpiConfiguration there but if this is done the run fails due to an MPI error that reads as if the cluster is configured to only allow one run per node:
Open RTE detected a bad parameter in hostfile: [...]
The max_slots parameter is less than the slots parameter:
slots = 3
max_slots = 1
[...] ORTE_ERROR_LOG: Bad Parameter in file util/hostfile/hostfile.c at line 407
Using HyperDriveConfig also defaults to submitting one run to one GPU and additionally providing a MpiConfiguration leads to the same error as shown above.
I guess I could always rewrite my train script to train multiple models in parallel, s.t. each run wraps multiple trainings. I would like to avoid this option though, because then logging and checkpoint writes become increasingly messy and it would require a large refactor of the train pipeline. Also this functionality seems so basic that I hope there is a way to do this gracefully. Any ideas?
Use Run.create_children method which will start child runs that are “local” to the parent run, and don’t need authentication.
For AMLcompute max_concurrent_runs map to maximum number of nodes that will be used to run a hyperparameter tuning run.
So there would be 1 execution per node.
single service deployed but you can load multiple model versions in the init then the score function, depending on the request’s param, uses particular model version to score.
or with the new ML Endpoints (Preview).
What are endpoints (preview) - Azure Machine Learning | Microsoft Docs

Training Stalls while saving checkpoint using pytorch

I am trying to save checkpoint while using pytorch in google colab.
When save it after all epochs are complete - it gets saved successfully. But, when I save it inside the for loop using below code, training stalls forever and pointer gets stuck at the line torch.save(checkpoint,....). A little help would be very useful.
if np.mean(tmp_eval_rmse) < best_valid_loss:
checkpoint = {"epoch":epoch_i, "model_state":model.state_dict(), "optim_state": optimizer.state_dict()}
torch.save(checkpoint, "/content/gdrive/MyDrive/Best_Model_Checkpoint.pth.tar")
best_valid_loss = np.mean(tmp_eval_rmse)
Regards,
Mithun Thakkar.

How are checkpoints created in a custom object detector with tensorflow 2 model zoo?

I've currently been training some models from the tensorflow2 object detection model zoo following the tutorial from https://tensorflow-object-detection-api-tutorial.readthedocs.io/en/latest/training.html.
One of my doubts arised when I was looking to export my model from a checkpoint that had the total loss that I was looking for. Nevertheless, I found that I had 16 checkpoints (just the last five of them) but only 1500 steps elapsed. I have to mention that I passed a flag to save a checkpoint every 100 steps. So I'm wondering if:
It creates an initial checkpoint, let's say the checkpoint 0 and if I want to export a model from the 1400th step I should take the 15th checkpoint
or
It creates a "placeholder" for the future checkpoint, i.e. If training process is currently in step 1500 it prepares to store the next checkpoint. I should then take just the 14th checkpoint.
I leave an image of reference,
In this example, I have 16 checkpoints but only 1500 steps have elapsed. I've chosen to save a new checkpoint every 100 steps. If I want to export a new model from the step 1400, should I export the 14th or 15th?
Any help would be much appreciated.

How do we know the model converged while training a neural network for object classification/detection?

I am using Tensorflow's Object Detection API to detect cars. It should detect the cars as one class "car".
I followed sentdex's following series:
https://pythonprogramming.net/introduction-use-tensorflow-object-detection-api-tutorial/
System information:
OS - Ubuntu 18.04 LTS
GPU - Nvidia 940M (VRAM : 2GB)
Tensorflow : 1.10
Python - 3.6
CPU - Intel i5
Problem:
The training process runs pretty fine. In order to know when the model converges and when I should stop training, I observe the loss during the training per step in the terminal where the training is running and also observe the Total Loss graph in Tensorboard via running the following command in another terminal,
$tensorboard --logdit="training"
But even after training till 60k steps, the loss fluctuates between 2.1 to 1.2. If I stop the training and export the inference graph from the last checkpoint(saved in the training/ folder), it detects cars in some cases and in some it gives false positives.
I also tried running eval.py like below,
python3 eval.py --logtostderr --pipeline_config_path=training/ssd_mobilenet_v1_pets.config --checkpoint_dir=training/ --eval_dir=eval/
but it gives out an error that indicates that the GPU memory fails to run this script along with train.py.
So, I stop the training to make sure the GPU is free and then run eval.py but it creates only one eval point in eval/ folder. Why?
Also, how do I understand from the Precision graphs in Tensorboard that the training needs to be stopped?
I could also post screenshots if anyone wants.
Should I keep training till the loss stays on an average around 1?
Thanks.
PS: Added Total Loss graph below till 66k steps.
PS2: After 2 days training(and still on) this is the total loss graph below.
Usually, one uses a separate set of data to measure the error and generalisation abilities of the model. So, one would have the following sets of data to train and evaluate a model:
Training set: The data used to train the model.
Validation set: A separate set of data which will be used to measure the error during training. The data of this set is not used to perform any weight updates.
Test set: This set is used to measure the model's performance after the training.
In your case, you would have to define a separate set of data, the validation set and run an evaluation repeadingly after a fixed number of batches/steps and log the error or accuracy. What usually happens is, that the error on that data will decrease in the beginning and increase at a certain point during training. So it's important to keep track of that error and to generate a checkpoint whenever this error is decreases. The checkpoint with the lowest error on your validation data is one that you want to use. This technique is called Early Stopping.
The reason why the error increases after a certain point during training is called Overfitting. It tells you that the model losses it's ability to generalize to unseen data.
Edit:
Here's an example of a training loop with early stopping procedure:
for step in range(1, _MAX_ITER):
if step % _TEST_ITER == 0:
sample_count = 0
while True:
try:
test_data = sess.run(test_batch)
test_loss, summary = self._model.loss(sess, test_data[0], self._assign_target(test_data), self._merged_summary)
sess.run(self._increment_loss_opt, feed_dict={self._current_loss_pl: test_loss})
sample_count += 1
except tf.errors.OutOfRangeError:
score = sess.run(self._avg_batch_loss, feed_dict={self._batch_count_pl: sample_count})
best_score =sess.run(self._best_loss)
if score < best_score:
'''
Save your model here...
'''

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