# Ray 2.40.0 — Ray-2.40.0

- Product: Ray (https://whatsnew.fyi/product/ray)
- Vendor: Anyscale
- Date: 2024-12-04
- Version: 2.40.0
- Original notes: https://github.com/ray-project/ray/releases/tag/ray-2.40.0
- Permalink: https://whatsnew.fyi/product/ray/releases/2.40.0

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'.

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- **added** — Add read_hudi function to Ray Data
- **changed** — Improve performance of DelegatingBlockBuilder
- **changed** — Improve memory accounting of pandas blocks
- **fixed** — Fix bug where you can't specify a schema with write_parquet
- **fixed** — Fix bug where to_pandas errors if your dataset contains Arrow and pandas blocks
- **fixed** — Fix bug where map_groups doesn't work with pandas data
- **fixed** — Fix bug where write_parquet errors if your data contains nullable fields
- **fixed** — Fix bug where "Iteration Blocked Time" charts looks incorrect
- **fixed** — Fix bug where unique fails with null values
- **fixed** — Fix bug where "Rows Outputted" is 0 in the Data dashboard
- **fixed** — Fix bug where methods like drop_columns cause spilling
- **fixed** — Fix bug where async map tasks hang
- **deprecated** — Deprecate read_parquet_bulk
- **deprecated** — Deprecate iter_tf_batches
- **deprecated** — Deprecate meta_provider parameter of read functions
- **deprecated** — Deprecate to_torch
- **fixed** — Fix StartTracebackWithWorkerRank serialization in Ray Train
- **added** — Add initial version of local_testing_mode to Ray Serve
- **changed** — Handle multiple changed objects per LongPollHost.listen_for_change RPC in Ray Serve
- **added** — Add uv runtime env support to Ray Core

#### Ray Libraries
##### Ray Data
🎉 New Features:
- Added read_hudi (https://github.com/ray-project/ray/pull/46273)

💫 Enhancements:
- Improved performance of DelegatingBlockBuilder (https://github.com/ray-project/ray/pull/48509)
- Improved memory accounting of pandas blocks (https://github.com/ray-project/ray/pull/46939)

🔨 Fixes:
- Fixed bug where you can’t specify a schema with write_parquet (https://github.com/ray-project/ray/issues/48630)
- Fixed bug where to_pandas errors if your dataset contains Arrow and pandas blocks (https://github.com/ray-project/ray/pull/48583)
- Fixed bug where map_groups doesn’t work with pandas data (https://github.com/ray-project/ray/pull/48287)
- Fixed bug where write_parquet errors if your data contains nullable fields (https://github.com/ray-project/ray/pull/48478)
- Fixed bug where “Iteration Blocked Time” charts looks incorrect (https://github.com/ray-project/ray/pull/48618)
- Fixed bug where unique fails with null values (https://github.com/ray-project/ray/pull/48750)
- Fixed bug where “Rows Outputted” is 0 in the Data dashboard (https://github.com/ray-project/ray/pull/48745)
- Fixed bug where methods like drop_columns cause spilling (https://github.com/ray-project/ray/pull/48140)
- Fixed bug where async map tasks hang (https://github.com/ray-project/ray/pull/48861)

🗑️ Deprecations:
- Deprecated read_parquet_bulk https://github.com/ray-project/ray/pull/48691
- Deprecated iter_tf_batches https://github.com/ray-project/ray/pull/48693
- Deprecated meta_provider parameter of read functions (https://github.com/ray-project/ray/pull/48690)
- Deprecated to_torch (https://github.com/ray-project/ray/pull/48692)

##### Ray Train
🔨 Fixes:
- Fix StartTracebackWithWorkerRank serialization (#48548)

📖 Documentation:
- Add example for fine-tuning Llama3.1 with AWS Trainium (#48768)

##### Ray Tune
🔨 Fixes:
- Remove the `clear_checkpoint` function during Trial restoration error handling. (#48532)

##### Ray Serve
🎉 New Features:
- Initial version of local_testing_mode ([#48477](https://github.com/ray-project/ray/pull/48477))

💫 Enhancements:
- Handle multiple changed objects per LongPollHost.listen_for_change RPC ([#48803](https://github.com/ray-project/ray/pull/48803/files))
- Add more nuanced checks for http proxy status errors ([#47896](https://github.com/ray-project/ray/pull/47896))
- Improve replica access log messages to include HTTP status info and better resemble standard log format ([#48819](https://github.com/ray-project/ray/pull/48819))
- Propagate replica constructor error to deployment status message and print num retries left ([#48531](https://github.com/ray-project/ray/pull/47896))

🔨 Fixes:
- Pending requests that are cancelled before they were assigned to a replica now also return a serve.RequestCancelledError ([#48496](https://github.com/ray-project/ray/pull/48496))

##### RLlib
💫 Enhancements:
- Release test enhancements. ([#45803](https://github.com/ray-project/ray/pull/45803), [#48681](https://github.com/ray-project/ray/pull/48681))
- Make opencv-python-headless default over opencv-python ([#48776](https://github.com/ray-project/ray/pull/48776)[)](https://github.com/ray-project/ray/commit/aaac19c8307038021dd96ffc4c2e616fbbf14896)
- Reverse learner queue behavior of IMPALA/APPO (consume oldest batches first, instead of newest, BUT drop oldest batches if queue full). ([#48702](https://github.com/ray-project/ray/pull/48702))

🔨 Fixes:
- Fix torch scheduler stepping and reporting. ([#48125](https://github.com/ray-project/ray/pull/48125)[)](https://github.com/ray-project/ray/commit/ec9775d86fbf7eb93358d95268e9f62e53f790bd)
- Fix accumulation of results over n training_step calls within same iteration (new API stack). ([#48136](https://github.com/ray-project/ray/pull/48136))
- Various other fixes: [#48563](https://github.com/ray-project/ray/pull/48563), [#48314](https://github.com/ray-project/ray/pull/48314), [#48698](h

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