# Ray 2.21.0 — Ray-2.21.0

- Product: Ray (https://whatsnew.fyi/product/ray)
- Vendor: Anyscale
- Date: 2024-05-08
- Version: 2.21.0
- Original notes: https://github.com/ray-project/ray/releases/tag/ray-2.21.0
- Permalink: https://whatsnew.fyi/product/ray/releases/2.21.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **added** — Add read_lance API to read Lance Dataset
- **fixed** — Retry RaySystemError application errors
- **removed** — Remove deprecated ray.air.callbacks modules
- **changed** — Allow methods to pass type @serve.batch type hint
- **changed** — Allow configuring Serve control loop interval
- **fixed** — Fix bug with controller failing to recover for autoscaling deployments
- **fixed** — Fix control+c after serve run doesn't shutdown serve components
- **fixed** — Fix lightweight update max ongoing requests
- **added** — New MetricsLogger API now fully functional on the new API stack, working inside Learner classes and loss functions
- **changed** — Rename WorkerSet to EnvRunnerGroup, DEFAULT_POLICY_ID to DEFAULT_MODULE_ID, config.rollouts() to config.env_runners()
- **changed** — Change behavior of EnvRunnerGroup.foreach_worker methods to mark_healthy=True and healthy_only=True as new defaults
- **fixed** — Fix get_state() and from_state() methods in SingleAgent and MultiAgentEpisodes
- **fixed** — Fix torch global_norm clipping overflow problem
- **fixed** — Fix ray.init(logging_format) argument is ignored
- **fixed** — Handle unserializable user exception
- **fixed** — Fix dashboard process event loop blocking issues
- **fixed** — Fix Nodes page sorting not working correctly
- **fixed** — Add back actors per page UI control in the actors page

#### Ray Libraries<a id="ray-libraries"></a>

##### Ray Data<a id="ray-data"></a>

🎉 New features:
- Add `read_lance` API to read Lance Dataset (#45106)

🔨 Fixes:
- Retry RaySystemError application errors (#45079)

📖 Documentation:
- Fix broken references in data documentation (#44956)

##### Ray Train<a id="ray-train"></a>

📖 Documentation:
- Fix broken links in Train documentation (#44953)

##### Ray Tune<a id="ray-tune"></a>

📖 Documentation:
- Update Hugging Face example to add reference (#42771)

🏗 Architecture refactoring:
- Remove deprecated `ray.air.callbacks` modules (#45104)

##### Ray Serve<a id="ray-serve"></a>

💫 Enhancements:
- Allow methods to pass type @serve.batch type hint (#45004)
- Allow configuring Serve control loop interval (#45063)

🔨 Fixes:
- Fix bug with controller failing to recover for autoscaling deployments (#45118)
- Fix control+c after serve run doesn't shutdown serve components (#45087)
- Fix lightweight update max ongoing requests (#45006)



##### RLlib<a id="rllib"></a>

🎉 New Features:
- New MetricsLogger API now fully functional on the new API stack (working now also inside Learner classes, i.e. loss functions). ([#44995](https://github.com/ray-project/ray/pull/44995), [#45109](https://github.com/ray-project/ray/pull/45109))

💫 Enhancements:
- Renamings and cleanups (toward new API stack and more consistent naming schemata): WorkerSet -> EnvRunnerGroup, DEFAULT_POLICY_ID -> DEFAULT_MODULE_ID, config.rollouts() -> config.env_runners(), etc.. ([#45022](https://github.com/ray-project/ray/pull/45022), [#44920](https://github.com/ray-project/ray/pull/44920))
- Changed behavior of `EnvRunnerGroup.foreach_worker…` methods to new defaults: `mark_healthy=True` (used to be False) and `healthy_only=True` (used to be False). ([#44993](https://github.com/ray-project/ray/pull/44993))
- Fix `get_state()/from_state()` methods in SingleAgent- and MultiAgentEpisodes. ([#45012](https://github.com/ray-project/ray/pull/45012))

🔨 Fixes:
- Bug fix for (torch) global_norm clipping overflow problem: ([#45055](https://github.com/ray-project/ray/pull/45055))
- Various bug- and test case fixes: [#45030](https://github.com/ray-project/ray/pull/45030), [#45031](https://github.com/ray-project/ray/pull/45031), [#45070](https://github.com/ray-project/ray/pull/45070), [#45053](https://github.com/ray-project/ray/pull/45053), [#45110](https://github.com/ray-project/ray/pull/45110), [#45111](https://github.com/ray-project/ray/pull/45111)

📖 Documentation:
- Example scripts using the MetricsLogger for env rendering and recording w/ WandB: [#45073](https://github.com/ray-project/ray/pull/45073), [#45107](https://github.com/ray-project/ray/pull/45107)

#### Ray Core<a id="ray-core"></a>

🔨 Fixes:
- Fix `ray.init(logging_format)` argument is ignored (#45037)
- Handle unserializable user exception (#44878)
- Fix dashboard process event loop blocking issues (#45048, #45047)

##### Dashboard<a id="dashboard"></a>
🔨 Fixes:
- Fix Nodes page sorting not working correctly.
- Add back “actors per page” UI control in the actors page.

Many thanks to all those who contributed to this release: @rynewang, @can-anyscale, @scottsun94, @bveeramani, @ceddy4395, @GeneDer, @zcin, @JoshKarpel, @nikitavemuri, @stephanie-wang, @jackhumphries, @matthewdeng, @yash97, @simonsays1980, @peytondmurray, @evalaiyc98, @c21, @alanwguo, @shrekris-anyscale, @kevin85421, @hongchaodeng, @sven1977, @st--, @khluu