ray.tune.schedulers.pb2.PB2.choose_trial_to_run

PB2.choose_trial_to_run(tune_controller: TuneController) → Optional[ray.tune.experiment.trial.Trial]

Ensures all trials get fair share of time (as defined by time_attr).

This enables the PBT scheduler to support a greater number of concurrent trials than can fit in the cluster at any given time.