[Doc] Document SimpleCPUOffloadConnector in the KV offloading guide#49048
[Doc] Document SimpleCPUOffloadConnector in the KV offloading guide#49048ayaangazali wants to merge 1 commit into
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The connector shipped in vllm-project#37160 and has since gained PCP/DCP support and packed HMA layouts, but had no end-user documentation: zero references under docs/ or examples/. Operators could only discover it by reading the connector factory. Adds a section to kv_offloading_usage.md covering the config keys the connector actually parses (cpu_bytes_to_use, cpu_bytes_to_use_per_rank, lazy_offload), the prefix-caching requirement, and a short comparison with OffloadingConnector. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Signed-off-by: ayaangazali <ayaangazali.work@gmail.com>
![claude[bot]](https://avatars.githubusercontent.com/in/1236702?s=60&v=4){kind=small}
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Documentation preview: https://vllm--49048.org.readthedocs.build/en/49048/ |
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Purpose
SimpleCPUOffloadConnector(added in #37160, since extended with PCP/DCP support in #39831 and packed HMA layouts in #46205) has no user-facing documentation at all: zero references underdocs/orexamples/. Right now the only way to find out it exists is to read the connector factory. This adds a section todocs/features/kv_offloading_usage.mdcovering it, plus a short neutral comparison withOffloadingConnectorso operators can pick between the two.Every documented key was verified against what the connector actually parses in
vllm/distributed/kv_transfer/kv_connector/v1/simple_cpu_offload_connector.py(cpu_bytes_to_usewith its 8 GiB default,cpu_bytes_to_use_per_rankprecedence and the mismatch warning,lazy_offload) andvllm/v1/simple_kv_offload/manager.py(eager vs lazy semantics, the prefix-caching requirement, KV events delegating to the CPU BlockPool viatake_events).Duplicate check: searched open PRs and issues for SimpleCPUOffload and kv_offloading_usage; the open SimpleCPUOffload PRs (#47324, #42615, #41777) are all code fixes, none touch docs.
Test Plan
Docs-only change:
plus checking each claim against the connector and manager source on current main.
Test Result
All pre-commit hooks pass (markdownlint etc.). Config keys, defaults, and mode semantics match the parsing code cited above.
small note: freshman contributor here, doing my best for the greater good :) I worked through the connector code myself and used Claude Code to help cross-check every config key against the source before writing it down. if the maintainers of either connector would phrase the comparison differently I am very happy to adjust.