Distributed Deep Reinforcement Learning: Learn How to Play Atari Games in 21 minutes

摘要

We present a study in Distributed Deep Reinforcement Learning (DDRL) focused on scalability of a state-of-the-art Deep Reinforcement Learning algorithm known as Batch Asynchronous Advantage Actor-Critic, (BA3C). We show that using the Adam optimization algorithm with a batch size of up to 2048 is a viable choice for carrying out large scale machine learning computations. This, combined with careful reexamination of the optimizer's hyperparameters, using synchronous training on the node level (while keeping the local, single node part of the algorithm asynchronous) and minimizing the model's memory footprint, allowed us to achieve linear scaling for up to 64 CPU nodes. This corresponds to a training time of 21 min on 768 CPU cores, as opposed to the 10 h required when using a single node with 24 cores achieved by a baseline single-node implementation.