The ASHA scheduler is an asynchronous successive-halving algorithm for hyperparameter optimization. It allocates resources preferentially to promising trials and early-stops underperforming configurations, reducing tuning time compared with exhaustive searches. section 8.2
Configuring ASHA with Ray Tune
A Ray Tune job searches learning rate, epochs, batch size, and weight decay against eval_loss. ASHA permits one epoch of initial progress, considers up to eight epochs, and uses a reduction factor of two before stopping weak trials.

