Change in logging frequency for automated logging

[nicoloesch]

Bug description

Utilising Automated Logging with self.log and self.log_dict as described in the documentation results in a shift of the logging frequency after various amounts of steps.

This is also observed in all train metrics but only in the _step. It could be mutually exclusive to the WandbLogger but has already been observed to some extent in the TensorboardLogger as reported in #13525 and more generally in #10436.

How to reproduce the bug

Call self.log(, on_step=True, on_epoch=True) in training_step and let it run for more than 15k steps (in my case).
The logging rate initial is equal to log_every_n_steps=50 for some iterations but jumps wildly around for others.

batch_size=10 (specified in self.log(batch_size=10))
test_subjects=20
samples_per_subject=10

This equals to 200 samples per epoch and 20 steps per epoch. Even if log_every_n_steps=50, this should log then precisely every 100 steps (as the first 50 is not met according to my understanding) and not jump around from 2 to 200.

Environment

• Lightning Component: Trainer/ LightningModule
• Python 3.9
• Pytorch-lightning 1.9.1 (installed with pip)
• PyTorch 1.13.1
• CUDA/ cuDNN: cuda11.6-cudnn8
• OS: Linux (Kernel 3.10.0-1160)
• Running environment: server

[stale]

This issue has been automatically marked as stale because it hasn't had any recent activity. This issue will be closed in 7 days if no further activity occurs. Thank you for your contributions - the Lightning Team!

[baskrahmer]

@nicoloesch could you provide a minimum working example? I was not able to reproduce the issue with your settings. Specifically, the following code works as expected (i.e. not showing any jump at around ~12k steps):

    class CustomModel(BoringModel):
        def training_step(self, batch, batch_idx):
            loss = self.step(batch)
            self.log("train_loss", loss, batch_size=10, on_step=True, on_epoch=True)
            return {"loss": loss}

    logger = WandbLogger()
    model = CustomModel()
    trainer = Trainer(max_steps=15000, log_every_n_steps=50, logger=logger, default_root_dir=tmpdir)
    trainer.fit(model)

My suspicion is that there is an interaction with the size of the training and validation sets, so maybe this could be included.

[nicoloesch]

@baskrahmer Thanks for the reply! I have recently changed over to the automated self.log in combination with the torchmetrics implementation and also WandbLogger as opposed to TensorboardLogger. For background, initially I called the functional interface of torchmetrics and created my own dictionary that is logged - most likely, that is where the mistake is arising from (?). Since I changed over to the fully automatic logging with the class interface of torchmetrics, I have not observed the behaviour of my initial bug report. I am not sure if you want to keep the issue open for some time (maybe a month as I currently use it almost daily) and I comment under it as soon as I observe it again, or if you/I close this issue and I open a new one with a working example if it occurs again?

Cheers,
Nico