[kingcrimsontianyu]

Description

KvikIO rapidsai/kvikio#1088 makes the MULTI_POLL reactors always take work from one shared queue, and deprecates the reactor dispatch setting. kvikio.defaults.get/set("remote_io_reactor_dispatch") now emits a FutureWarning, and setting it has no effect. cudf-polars calls both whenever it configures KvikIO for a MULTI_POLL engine, which breaks the test suite under the filterwarnings = error setup.

This PR removes the kvikio_reactor_dispatch executor option and its CUDF_POLARS__EXECUTOR__KVIKIO_REACTOR_DISPATCH environment variable, so cudf-polars no longer reads or sets the dispatch in KvikIO. This is a breaking change. Once #1088 is merged the option would have no effect anyway.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[copy-pr-bot]

Auto-sync is disabled for draft pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Source mode: Auto
• Repository: NVIDIA/cudf
• Branch: main
• File: .coderabbit.yaml
• Commit: e0d6a75
• Layers: Repository YAML
• Review profile: CHILL
• Plan: Enterprise
• Run ID: 8fe206d6-be1d-4988-8372-47a90cae3534

📥 Commits

Reviewing files that changed from the base of the PR and between c9e4252 and 750abdb.

📒 Files selected for processing: 5

• python/cudf_polars/cudf_polars/engine/dask.py
• python/cudf_polars/cudf_polars/engine/ray.py
• python/cudf_polars/cudf_polars/engine/spmd.py
• python/cudf_polars/cudf_polars/utils/config.py
• python/cudf_polars/tests/test_config.py

💤 Files with no reviewable changes: 5

• python/cudf_polars/tests/test_config.py
• python/cudf_polars/cudf_polars/engine/spmd.py
• python/cudf_polars/cudf_polars/utils/config.py
• python/cudf_polars/cudf_polars/engine/ray.py
• python/cudf_polars/cudf_polars/engine/dask.py

Included review availability: This review used your included allowance. Your plan provides up to 12 included reviews per hour; 11 remain after this review.

📝 Summary

Summary by CodeRabbit

• Configuration Changes
  • The KvikIO reactor dispatch setting has been removed and is no longer configurable in streaming, Dask, Ray, or SPMD execution.
  • Remote I/O configuration continues to use reactor count and request ceiling settings.
  • MULTI_POLL documentation now identifies reactor count and request ceiling as the relevant settings.
  • Existing configurations that specify reactor dispatch will need to rely on the remaining supported KvikIO settings instead.

The kvikio_reactor_dispatch option and its configuration and forwarding paths are removed. KvikIO configuration continues to use reactor count and request ceiling.

Changes: KvikIO reactor dispatch

Layer / File(s)	Summary
Remove the dispatch option python/cudf_polars/cudf_polars/engine/options.py, python/cudf_polars/cudf_polars/utils/config.py	The streaming and executor configuration no longer exposes, resolves, stores, or normalizes kvikio_reactor_dispatch.
Remove dispatch from KvikIO configuration python/cudf_polars/cudf_polars/utils/config.py, python/cudf_polars/cudf_polars/engine/core.py, python/cudf_polars/tests/test_config.py	The KvikIO configuration API and MULTI_POLL settings no longer include reactor dispatch. The concurrency-options description and configuration tests no longer list or assert it.
Remove engine dispatch forwarding python/cudf_polars/cudf_polars/engine/dask.py, python/cudf_polars/cudf_polars/engine/ray.py, python/cudf_polars/cudf_polars/engine/spmd.py	Dask, Ray, and SPMD setup and reset paths no longer pass reactor dispatch. Related worker and actor parameters and documentation are removed.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested labels: bug

Merge Risk: ⚪ Minimal · up to 750ab

The dispatch option has been removed consistently from the inspected configuration and engine paths. No issue requiring a fix before merge was identified.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 38.46% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 13 functions across 4 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Title check		The title clearly and concisely identifies the main change: removal of the cudf-polars kvikio_reactor_dispatch option.
Description check		The description directly explains the KvikIO compatibility issue, the removed option and environment variable, the breaking change, and the related test and documentation updates.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

_{Comment @coderabbitai help to get the list of available commands.}

[TomAugspurger]

CI will need to wait for #24775.

[kingcrimsontianyu]

/merge