fix(cache): include artifact URIs in cache key to prevent incorrect r…

[Aman-Cool]

Fix Cache Key Collisions for Input Artifacts with Different URIs

Summary

This change fixes an issue in KFP v2 cache key generation where only input artifact logical names were considered.
As a result, tasks could incorrectly reuse cached outputs even when they were executed with different input data locations (URIs).

Problem

Cache keys were generated using artifact names only, ignoring the artifact URI that identifies the actual data source.
If the same pipeline was run multiple times with the same artifact name but different URIs, the cache would treat them as identical and return previously cached results.

This caused silent and incorrect cache hits when:

• Re-running pipelines with new dataset versions
• Sharing pipeline templates across teams or tenants
• Running experiments or A/B tests on different input data

Fix

The cache key now includes the artifact URI alongside the name (name@uri) when generating the cache identifier.
This ensures cache hits occur only when input artifacts truly refer to the same data.

Artifacts without a URI continue to fall back to name-only behavior for backward compatibility.

Tests

Existing cache tests were updated, and new tests were added to validate that:

• Same artifact name + different URI → different cache fingerprints
• Same name + same URI → cache hit
• Artifacts without URIs remain supported

Behavior Change

Previously cached executions will no longer match under the new cache key format, resulting in cache misses.
This is expected and correct, as it prevents reuse of outputs computed from different inputs.

Result

• Correct cache behavior for dataset versioning and multi-tenant usage
• No more silent reuse of outputs from different data sources
• Deterministic and trustworthy caching semantics

[github-actions]

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[google-oss-prow]

Hi @Aman-Cool. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[Aman-Cool]

@mprahl @droctothorpe ,Fixes incorrect cache reuse by including input artifact URIs in cache keys; existing cached runs may miss once, as expected.

[hbelmiro]

/ok-to-test

[zazulam]

@Aman-Cool Thanks for this contribution, but can you remove the comments from the proto file? I think just documenting it in cache.go would be fine.

[google-oss-prow]

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[Aman-Cool]

@zazulam , Removed the comments from the proto file and kept the documentation in cache.go only, as suggested.

[zazulam]

@Aman-Cool can you run the repo's pre-commit hooks?

[Aman-Cool]

@zazulam ,Pre-commit hooks have been run locally and the resulting fixes are pushed.