AutoRL Hyperparameter Landscapes
This work addresses a critical bottleneck for practitioners in reinforcement learning by offering insights into AutoRL dynamics, though it is incremental as it builds on existing AutoRL approaches.
The paper tackles the problem of hyperparameter sensitivity in reinforcement learning by analyzing how hyperparameter landscapes change over time during training, providing empirical evidence that these landscapes vary significantly across algorithms and environments, which supports the need for dynamic hyperparameter adjustment.
Although Reinforcement Learning (RL) has shown to be capable of producing impressive results, its use is limited by the impact of its hyperparameters on performance. This often makes it difficult to achieve good results in practice. Automated RL (AutoRL) addresses this difficulty, yet little is known about the dynamics of the hyperparameter landscapes that hyperparameter optimization (HPO) methods traverse in search of optimal configurations. In view of existing AutoRL approaches dynamically adjusting hyperparameter configurations, we propose an approach to build and analyze these hyperparameter landscapes not just for one point in time but at multiple points in time throughout training. Addressing an important open question on the legitimacy of such dynamic AutoRL approaches, we provide thorough empirical evidence that the hyperparameter landscapes strongly vary over time across representative algorithms from RL literature (DQN, PPO, and SAC) in different kinds of environments (Cartpole, Bipedal Walker, and Hopper) This supports the theory that hyperparameters should be dynamically adjusted during training and shows the potential for more insights on AutoRL problems that can be gained through landscape analyses. Our code can be found at https://github.com/automl/AutoRL-Landscape