feat(cadence-matching): Add drain observer for SD executor client#7751
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gazi-yestemirova merged 1 commit intocadence-workflow:masterfrom Feb 26, 2026
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Signed-off-by: Gaziza Yestemirova <gaziza@uber.com>
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Code Review ✅ ApprovedClean parameter threading for drain observer through the matching service initialization chain. Follows the established pattern, is nil-safe, and tests are updated appropriately. Rules ❌ No requirements metRepository Rules
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What changed?
This PR adds DrainObserver field to resource.Params to inject a DrainSignalObserver into the matching service at initialization.
We wire the drain observer through matching.Service -> handler.NewEngine -> setupExecutor -> executorclient.Params, enabling the executor client's heartbeat loop to react to infrastructure drain/undrain signals.
Why?
The shard-distributor executor client already supports drain-aware behavior via the DrainObserver field on executorclient.Params. However, there was no way to wire a DrainSignalObserver into the matching service's executor client because resource.Params didn't have it.
PR follows the same pattern used by ShardDistributorMatchingConfig initialization.
How did you test it?
Unit tests with
go test -v ./service/matching/handler/Potential risks
Since drainObserver field is optional there wouldn't be any changes in cadence-matching's behaviour.
Release notes
N/A
Documentation Changes
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Reviewer Validation
PR Description Quality (check these before reviewing code):
go testinvocation)