Environment Samplers
Contents
Environment Samplers#
When a simulator (environment) is available, InputReader - are used to collect and return experiences from the envs.
For more details on InputReader used for offline RL (e.g. reading files of
pre-recorded data), see the offline RL API reference here.
The base sampler API (SamplerInput) is defined as follows:
Base Sampler class (ray.rllib.evaluation.sampler.SamplerInput)#
SyncSampler (ray.rllib.evaluation.sampler.SyncSampler)#
The synchronous sampler starts stepping through and collecting samples from an
environment only when its next() method is called. Calling this method blocks
until a SampleBatch has been built and is returned.
AsyncSampler (ray.rllib.evaluation.sampler.AsyncSampler)#
The asynchronous sampler has a separate thread that keeps stepping through and
collecting samples from an environment in the background. Calling its next() method
gets the next enqueued SampleBatch from a queue and returns it immediately.