class ray.tune.logger.LoggerCallback[source]#

Bases: ray.tune.callback.Callback

Base class for experiment-level logger callbacks

This base class defines a general interface for logging events, like trial starts, restores, ends, checkpoint saves, and receiving trial results.

Callbacks implementing this interface should make sure that logging utilities are cleaned up properly on trial termination, i.e. when log_trial_end is received. This includes e.g. closing files.

PublicAPI: This API is stable across Ray releases.




Get the state of the callback.

log_trial_end(trial[, failed])

Handle logging when a trial ends.


Handle logging when a trial restores.

log_trial_result(iteration, trial, result)

Handle logging when a trial reports a result.


Handle logging when a trial saves a checkpoint.


Handle logging when a trial starts.

on_checkpoint(iteration, trials, trial, ...)

Called after a trial saved a checkpoint with Tune.

on_experiment_end(trials, **info)

Called after experiment is over and all trials have concluded.

on_step_begin(iteration, trials, **info)

Called at the start of each tuning loop step.

on_step_end(iteration, trials, **info)

Called at the end of each tuning loop step.

on_trial_recover(iteration, trials, trial, ...)

Called after a trial instance failed (errored) but the trial is scheduled for retry.


Set the state of the callback.

setup([stop, num_samples, total_num_samples])

Called once at the very beginning of training.