Highlights

🎉 Ray no longer starts Redis by default. Cluster metadata previously stored in Redis is stored in the GCS now.

Ray Autoscaler

🎉 New Features

• AWS Cloudwatch dashboard support #20266

💫 Enhancements

• Kuberay autoscaler prototype #21086

🔨 Fixes

• Ray.autoscaler.sdk import issue #21795

Ray Core

🎉 New Features

• Set actor died error message in ActorDiedError #20903
• Event stats is enabled by default #21515

🔨 Fixes

• Better support for nested tasks
• Fixed 16GB mac perf issue by limit the plasma store size to 2GB #21224
• Fix SchedulingClassInfo.running_tasks memory leak #21535
• Round robin during spread scheduling #19968

🏗 Architecture refactoring

• Refactor scheduler resource reporting public APIs #21732
• Refactor ObjectManager wait logic to WaitManager #21369

Ray Data Processing

🎉 New Features

• More powerful to_torch() API, providing more control over the GPU batch format. (#21117)

🔨 Fixes

• Fix simple Dataset sort generating only 1 non-empty block. (#21588)
• Improve error handling across sorting, groupbys, and aggregations. (#21610, #21627)
• Fix boolean tensor column representation and slicing. (#22358)

RLlib

🎉 New Features

• Better utils for flattening complex inputs and enable prev-actions for LSTM/attention for complex action spaces. (#21330)
• MultiAgentEnv pre-checker (#21476)
• Base env pre-checker. (#21569)

🔨 Fixes

• Better defaults for QMix (#21332)
• Fix contrib/MADDPG + pettingzoo coop-pong-v4. (#21452)
• Fix action unsquashing causes inf/NaN actions for unbounded action spaces. (#21110)
• Ignore PPO KL-loss term completely if kl-coeff == 0.0 to avoid NaN values (#21456)
• unsquash_action and clip_action (when None) cause wrong actions computed by Trainer.compute_single_action. (#21553)
• Conv2d default filter tests and add default setting for 96x96 image obs space. (#21560)
• Bing back and fix offline RL(BC & MARWIL) learning tests. (#21574, #21643)
• SimpleQ should not use a prio. replay buffer. (#21665)
• Fix video recorder env wrapper. Added test case. (#21670)

🏗 Architecture refactoring

• Decentralized multi-agent learning (#21421)
• Preparatory PR for multi-agent multi-GPU learner (alpha-star style) (#21652)

Ray Workflow

🔨 Fixes

• Fixed workflow recovery issue due to a bug of dynamic output #21571

Tune

🎉 New Features

• It is now possible to load all evaluated points from an experiment into a Searcher (#21506)
• Add CometLoggerCallback (#20766)

💫 Enhancements

• Only sync the checkpoint folder instead of the entire trial folder for cloud checkpoint. (#21658)
• Add test for heterogeneous resource request deadlocks (#21397)
• Remove unused return_or_clean_cached_pg (#21403)
• Remove TrialExecutor.resume_trial (#21225)
• Leave only one canonical way of stopping a trial (#21021)

🔨 Fixes

• Replace deprecated running_sanity_check with sanity_checking in PTL integration (#21831)
• Fix loading an ExperimentAnalysis object without a registered Trainable (#21475)
• Fix stale node detection bug (#21516)
• Fixes to allow tune/tests/test_commands.py to run on Windows (#21342)
• Deflake PBT tests (#21366)
• Fix dtype coercion in tune.choice (#21270)

📖 Documentation

• Fix typo in schedulers.rst (#21777)

Train

🎉 New Features

• Add PrintCallback (#21261)
• Add MLflowLoggerCallback(#20802)

💫 Enhancements

• Refactor Callback implementation (#21468, #21357, #21262)

🔨 Fixes

• Fix Dataloader (#21467)

📖 Documentation

• Documentation and example fixes (#​​21761, #21689, #21464)

Serve

🎉 New Features

• Checkout our revampt end-to-end tutorial that walks through the deployment journey! (#20765)

🔨 Fixes

• Warn when serve.start() with different options (#21562)
• Detect http.disconnect and cancel requests properly (#21438)

Thanks Many thanks to all those who contributed to this release! @isaac-vidas, @wuisawesome, @stephanie-wang, @jon-chuang, @xwjiang2010, @jjyao, @MissiontoMars, @qbphilip, @yaoyuan97, @gjoliver, @Yard1, @rkooo567, @talesa, @czgdp1807, @DN6, @sven1977, @kfstorm, @krfricke, @simon-mo, @hauntsaninja, @pcmoritz, @JamieSlome, @chaokunyang, @jovany-wang, @sidward14, @DmitriGekhtman, @ericl, @mwtian, @jwyyy, @clarkzinzow, @hckuo, @vakker, @HuangLED, @iycheng, @edoakes, @shrekris-anyscale, @robertnishihara, @avnishn, @mickelliu, @ndrwnaguib, @ijrsvt, @Zyiqin-Miranda, @bveeramani, @SongGuyang, @n30111, @WangTaoTheTonic, @suquark, @richardliaw, @qicosmos, @scv119, @architkulkarni, @lixin-wei, @Catch-Bull, @acxz, @benblack769, @clay4444, @amogkam, @marin-ma, @maxpumperla, @jiaodong, @mattip, @isra17, @raulchen, @wilsonwang371, @carlogrisetti, @ashione, @matthewdeng