[BugFix] Avoid calling KV connector layer APIs when metadata is unset #28253
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Signed-off-by: David Ben-David <[email protected]> Co-authored-by: Mark McLoughlin <[email protected]>
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Code Review
This pull request effectively resolves a bug related to CUDA graph capture when using a KV connector. The core of the fix is to prevent calls to KV connector APIs when connector metadata is not set, which is the case during graph capture. This is cleanly implemented by introducing a has_connector_metadata method on the base connector class and adding checks in the attention layer. The accompanying change in MultiConnector to correctly propagate metadata state by calling the superclass methods is a crucial and well-spotted related fix. The changes are logical, well-contained, and directly address the issue described. The approach is sound, and I have no further comments.
heheda12345
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Nov 11, 2025
This was referenced Nov 12, 2025
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Nov 13, 2025
…vllm-project#28253) Signed-off-by: David Ben-David <[email protected]> Co-authored-by: David Ben-David <[email protected]> Co-authored-by: Mark McLoughlin <[email protected]> Signed-off-by: xuebwang-amd <[email protected]>
devpatelio
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…vllm-project#28253) Signed-off-by: David Ben-David <[email protected]> Co-authored-by: David Ben-David <[email protected]> Co-authored-by: Mark McLoughlin <[email protected]>
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Purpose
Fixes #26675, following the approach suggested by @markmc in #27026.
This change temporarily disables graph capture for the KV connector path by skipping calls to KV connector layer APIs when the connector metadata is unset.
Test Plan
Reproduce the scenario described in #26675 (full-graph capture with KV connector).
Run with and without the fix applied.
Test Result
With the fix applied, the assertion reported in #26675 no longer reproduces.
Full-graph capture completes successfully with the KV connector enabled.