Optimizing Distributed Reinforcement Learning with Reactor Model and Lingua Franca

Distributed Reinforcement Learning (RL) frameworks are essential for mapping RL workloads to multiple computational resources, allowing for faster generation of samples, estimation of values, and policy improvement. These computational paradigms require a seamless integration of training, serving, and simulation workloads. Existing frameworks, such as Ray, are not managing this orchestration efficiently. In this study, we've proposed a solution implementing Reactor Model, which enforces a set of actors to have a fixed communication pattern. This allows the scheduler to eliminate works needed for synchronization, such as acquiring and releasing locks for each actor or sending and processing coordination-related messages. Our framework, Lingua Franca (LF), a coordination language based on the Reactor Model, also provides a unified interface that allows users to automatically generate dataflow graphs for distributed RL. On average, LF outperformed Ray in generating samples from OpenAI Gym and Atari environments by 1.21x and 11.62x, reduced the average training time of synchronized parallel Q-learning by 31.2%, and accelerated Multi-Agent RL inference by 5.12x.