make init_trackers to launch on main process

[Gladiator07]

While on distributed setup the accelerator.init_trackers() method initializes multiple runs of the tracker on all processes. It should be initialized on the main process. Added a @on_main_process decorator to achieve the expected behavior.

@muellerzr @sgugger

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[muellerzr]

Thanks! For right now I think this is fine, and if folks don't like it we can revert back or make it optional to do so. There may be situations when spinning up a tracker on all the processes could be useful (and then manually logging them instead), so we'll keep an eye out for this on feedback

[muellerzr]

@Gladiator07 could you adjust the following code in the examples as well? Since this removes the need for the check:

https://github.com/huggingface/accelerate/blob/main/examples/by_feature/tracking.py#L168-L172

[Gladiator07]

@muellerzr adjust as in? Should I remove the accelerator.is_main_process check?

[muellerzr]

@Gladiator07 correct. We're putting this in place so that is no longer needed, so the examples should show this :)

[Gladiator07]

Cool, doing this in a separate PR.