Ray 0.7.7 Release Notes

Highlights

• Remote functions and actors now support kwargs and positionals (#5606).
• ray.get now supports a timeout argument (#6107). If the object isn't available before the timeout passes, a RayTimeoutError is raised.
• Ray now supports detached actors (#6036), which persist beyond the lifetime of the script that creates them and can be referred to by a user-defined name.
• Added documentation for how to deploy Ray on YARN clusters using Skein (#6119, #6173).
• The Ray scheduler now attempts to schedule tasks fairly to avoid starvation (#5851).

Core

• Progress towards a new backend architecture where tasks and actor tasks are submitted directly between workers. #5783, #5991, #6040, #6054, #6075, #6088, #6122, #6147, #6171, #6177, #6118, #6188, #6259, #6277
• Progress towards Windows compatibility. #6071, #6204, #6205, #6282
• Now using cloudpickle_fast for serialization by default, which supports more types of Python objects without sacrificing performance. #5658, #5805, #5960, #5978
• Various bugfixes. #5946, #6175, #6176, #6231, #6253, #6257, #6276,

RLlib

• Now using pytorch's function to see if gpu is available. #5890
• Fixed APEX priorities returning zero all the time. #5980
• Fixed leak of TensorFlow assign operations in DQN/DDPG. #5979
• Fixed choosing the wrong neural network model for Atari in 0.7.5. #6087
• Added large scale regression test for RLlib. #6093
• Fixed and added test for LR annealing config. #6101
• Reduced log verbosity. #6154
• Added a microbatch optimizer with an A2C example. #6161

Tune

• Search algorithms now use early stopped trials for optimization. #5651
• Metrics are now outputted via a tabular format. Errors are outputted on a separate table. #5822
• In the distributed setting, checkpoints are now deleted automatically post-sync using an rsync flag. Checkpoints on the driver are garbage collected according to the policy defined by the user. #5877
• A much faster ExperimentAnalysis tool. #5962
• Trial executor callbacks now take in a “Runner” parameter. #5868
• Fixed queue_trials so to enable cluster autoscaling with a CPU-Only Head Node. #5900
• Added a TensorBoardX logger. #6133

Other Libraries

• Serving: Progress towards a new Ray serving library. #5854, #5886, #5894, #5929, #5937, #5961, #6051

Thanks

We thank the following contributors for their amazing contributions:

@zhuohan123, @jovany-wang, @micafan, @richardliaw, @waldroje, @mitchellstern, @visatish, @mehrdadn, @istoica, @ericl, @adizim, @simon-mo, @lsklyut, @zhu-eric, @pcmoritz, @hhbyyh, @suquark, @sotte, @hershg, @pschafhalter, @stackedsax, @edoakes, @mawright, @stephanie-wang, @ujvl, @ashione, @couturierc, @AdamGleave, @robertnishihara, @DaveyBiggers, @daiyaanarfeen, @danyangz, @AmeerHajAli, @mimoralea