# Ray 2.55.0 — Ray-2.55.0

- Product: Ray (https://whatsnew.fyi/product/ray)
- Vendor: Anyscale
- Date: 2026-04-15
- Version: 2.55.0
- Original notes: https://github.com/ray-project/ray/releases/tag/ray-2.55.0
- Permalink: https://whatsnew.fyi/product/ray/releases/2.55.0

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 DataSourceV2 API with scanner/reader framework, file listing, and file partitioning
- **added** — Support GPU shuffle with rapidsmpf 26.2
- **added** — Add Kafka datasink, migrate to confluent-kafka, support datetime offsets
- **added** — Add Turbopuffer datasink
- **added** — Add 2-phase commit checkpointing with trie recovery and load method
- **added** — Integrate queue-based autoscaling policy with task consumers
- **added** — Enable autoscaling for GPU stages
- **added** — Add random(), uuid(), cast, and map namespace support to Expressions
- **added** — Add support for Arrow native fixed-shape tensor type
- **added** — Support writing tensors to tfrecords
- **added** — Add pathlib.Path support to read_* functions
- **added** — Add cudf as a batch_format
- **added** — Allow ActorPoolStrategy for read_datasource() via compute parameter
- **added** — Introduce ExecutionCache for streamlined caching
- **added** — Support strict=False mode for StreamingRepartition
- **added** — Add monotonically increasing ID support
- **changed** — Cache _map_task args, improve heap-based actor ranking, and improve actor pool map
- **changed** — Optimize concat tables and PyArrow schema hashing
- **changed** — Reduce default DownstreamCapacityBackpressurePolicy threshold to 50%
- **changed** — Improve reproducibility for random APIs
- **changed** — Port changes from lance-ray into Ray Data
- **changed** — Enable PyArrow compute-to-expression conversion for predicate pushdown
- **changed** — Upgrade to pyiceberg 0.11.0 and cap pandas to <3
- **changed** — Refactor logical operators to frozen dataclasses
- **fixed** — Fix RCE in Arrow extension type deserialization from Parquet
- **fixed** — Fix StreamingSplitDataIterator.schema()
- **fixed** — Fix ParquetDatasource handling of FileSystemFactory.inspect
- **fixed** — Fix read_parquet file-extension filtering for versioned object-store URIs
- **fixed** — Fix wide_schema_pipeline_tensors cloudpickle deserialization
- **fixed** — Fix OpBufferQueue race condition
- **fixed** — Fix scheduling metrics computation
- **fixed** — Fix OneHotEncoder max_categories to use global top-k instead of per-partition
- **fixed** — Fix ReservationOpResourceAllocator resource borrowing for ActorPoolMapOperator
- **fixed** — Fix DatabricksUCDatasource schema() shadowing by schema string attribute
- **fixed** — Fix AliasExpr structural equality to respect rename flag
- **fixed** — Fix _align_struct_fields failure with unaligned scalar fields
- **fixed** — Fix min_scheduling_resources fallback to incremental_resource_usage
- **fixed** — Fix output backpressure unblocking sequence for terminal ops
- **fixed** — Fix multi-input operator object store memory attribution
- **fixed** — Fix reference cycle by moving to module scope
- **fixed** — Replace on_exit hook with __ray_shutdown__ to fix UDF cleanup race
- **fixed** — Prevent Limit from getting pushed past map_groups
- **fixed** — Propagate schema in empty _shuffle_block to fix ColumnNotFound in chained left joins
- **fixed** — Clamp rolling utilization averages to zero
- **fixed** — Fix floating point errors in TimeWindowAverageCalculator
- **fixed** — Remove default task-level timeout and clamp end_offset in Kafka datasource
- **fixed** — Avoid redundant reads in train_test_split
- **fixed** — Return None when no outputs have been produced
- **removed** — Remove legacy BlockList, locality_with_output, old callback API, and PyArrow 9.0 checks

##### Ray Data

###### 🎉 New Features

- Add `DataSourceV2` API with scanner/reader framework, file listing, and file partitioning (#61220, #61615, #61997)
- Support GPU shuffle with `rapidsmpf` 26.2 (#61371, #62062)
- Add Kafka datasink, migrate to `confluent-kafka`, support `datetime` offsets (#60307, #61284, #60909)
- Add Turbopuffer datasink (#58910)
- Add 2-phase commit checkpointing with trie recovery and load method (#61821, #60951)
- Queue-based autoscaling policy integrated with task consumers (#59548, #60851)
- Enable autoscaling for GPU stages (#61130)
- Expressions: add `random()`, `uuid()`, `cast`, and map namespace support (#59656, #60695, #59879)
- Add support for Arrow native fixed-shape tensor type (#56284)
- Support writing tensors to tfrecords (#60859)
- Add `pathlib.Path` support to `read_*` functions (#61126)
- Add `cudf` as a `batch_format` (#61329)
- Allow `ActorPoolStrategy` for `read_datasource()` via `compute` parameter (#59633)
- Introduce `ExecutionCache` for streamlined caching (#60996)
- Support `strict=False` mode for `StreamingRepartition` (#60295)
- Port changes from lance-ray into Ray Data (#60497)
- Enable PyArrow compute-to-expression conversion for predicate pushdown (#61617)
- Add vLLM metrics export and Data LLM Grafana dashboard (#60385)
- Include logical memory in resource manager scheduling decisions (#60774)
- Add monotonically increasing ID support (#59290)

###### 💫 Enhancements
- Performance: cache `_map_task` args, heap-based actor ranking, actor pool map improvements (#61996, #62114, #61591)
- Optimize concat tables and PyArrow schema hashing (#61315, #62108)
- Reduce default `DownstreamCapacityBackpressurePolicy` threshold to 50% (#61890)
- Improve reproducibility for random APIs (#59662)
- Clamp batch size to fall within C++ 32-bit int range (#62242)
- Account for external consumer object store usage in resource manager budget (#62117)
- Make `get_parquet_dataset` configurable in number of fragments to scan (#61670)
- Consolidate schema inference and make all preprocessors implement `SerializablePreprocessorBase` (#61213, #61341)
- Disable hanging issue detection by default (#62405)
- Make execution callback dataflow explicit to prevent state leakage (#61405)
- Log `DataContext` in JSON format at execution start for traceability (#61150, #61428)
- Autoscaler: configurable traceback, Prometheus gauges, relaxed constraints (#62210, #62209, #61917, #61385)
- Add metrics for task scheduling time, output backpressure, and logical memory (#61192, #61007, #61436)
- Prevent operators from dominating entire shared object store budget (#61605)
- Eliminate generators to avoid intermediate state pinning (#60598)
- Default log encoding to UTF-8 on Windows (#61143)
- Remove legacy `BlockList`, `locality_with_output`, old callback API, PyArrow 9.0 checks (#60575, #61044, #62055, #61483)
- Upgrade to `pyiceberg` 0.11.0; cap `pandas` to <3 (#61062, #60406)
- Refactor logical operators to frozen dataclasses (#61059, #61308, #61348, #61349, #61351, #61364, #61481)
- Prevent aggregator head node scheduling (#61288)
- Add error for `local://` paths with a zero-resource head node (#60709)

###### 🔨 Fixes
- Fix RCE in Arrow extension type deserialization from Parquet (#62056)
- Fix `StreamingSplitDataIterator.schema()` (#62057)
- Fix `ParquetDatasource` handling of `FileSystemFactory.inspect` (#62065)
- Fix `read_parquet` file-extension filtering for versioned object-store URIs (#61376)
- Fix `wide_schema_pipeline_tensors` cloudpickle deserialization (#62149)
- Fix `OpBufferQueue` race condition (#60828)
- Fix scheduling metrics computation (#62031)
- Fix `OneHotEncoder` `max_categories` to use global top-k instead of per-partition (#60790)
- Fix `ReservationOpResourceAllocator` resource borrowing for `ActorPoolMapOperator` (#60882)
- Fix `DatabricksUCDatasource` `schema()` shadowing by schema string attribute (#61282)
- Fix `AliasExpr` st

_[Truncated at 4000 characters — full notes: https://github.com/ray-project/ray/releases/tag/ray-2.55.0]_