Sandbox::https://github.com/dotnet/SqlClient/pull/5039

mdaigle · 2026-11-11T17:06:31Z

🤖 This pull request was created by a fully automated workflow.

Description

Fix DbConnectionPoolInstrumentationTest.ConcurrentCheckoutAndReturn_SettlesAllGaugesToZero by configuring the instrumentation class's pool wait in milliseconds to match its existing 30-second caller budget. The shared harness otherwise supplies only 15 ms, so ordinary contention can return null before the concurrent instrumentation test finishes.

Keep all 400 checkouts, eight workers, four pool slots and counter assertions. A controlled held-slot regression exercises the same fixture: WaitHandle failed before correction on both frameworks; Channel controls passed. All instrumentation tests use one common 30-second creation timeout, without a checkout-specific helper. The shared harness used by other classes is unchanged. No production API, dependency, localization or pipeline changes.

Retain flaky and add probation; the monitoring interval begins only when a merge makes the repair and both markings effective upstream.

Issues

#5020 quarantined this exact theory; its flaky marking is preserved. No issue is closed.

Testing

dotnet test src\Microsoft.Data.SqlClient\tests\UnitTests\Microsoft.Data.SqlClient.UnitTests.csproj --no-restore -c Release --filter "FullyQualifiedName~DbConnectionPoolInstrumentationTest" -v:q --blame-hang-timeout 2m — passed: 30 net462 / 30 net10.0, zero skipped. Debug also passed 30 per framework after the shared-timeout simplification in 43af4017a.

Controlled regression: failed before / passed after on both frameworks. Ordinary filters exclude the affected theory; existing quarantine filters select it. On predecessor 786757aa8, CI individually verified both original cases and both regressions passing on Windows net462/net10.0 Release/Project and net10.0 Release/Package; ordinary Debug CI also passed the regressions on Windows and Linux. Current-head CI is pending. Broader prior runs retain unrelated quarantine hangs/job timeouts and a Linux result-publication error; no full-suite pass is claimed. Maintained evidence contains additional result provenance and coverage boundaries.

Tests added or updated
Public API changes documented (none; test-only correction)
Verified against customer repro (not applicable; CI failure and controlled contention regression)
Ensure no breaking changes introduced (production behavior unchanged)

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mdaigle · 2026-11-11T17:09:06Z

Additional validation evidence

Historical WaitHandle comparison, same source
5aaa9ef090135a9a462f31d2e7945d97baa9e65b, definition 1879,
Release/Project, Win22_Sql17/net462_AnyCPU_3, attempt 1:
failure: 190106/3682592/102426
at 2026-11-07T01:18:17.760Z (Assert.NotNull, 67 ms);
passing control: 190082/3682470/104475
at 2026-11-06T23:43:16.983Z.

For predecessor 786757aa8fca40ddc038fc62346472138e01315b, these are individually verified
passing results, not aggregate job-status inferences. Pairs are WaitHandle/Channel;
the regression is ConcurrentCheckoutAndReturn_HeldSlot_WaitsAndBalancesCounters.
All rows: Release/AnyCPU, Windows Server 2022, Win22_Sql17, attempt 1.

Build / run	References / framework / SNI job	Affected theory IDs	Regression IDs	UTC interval, 2026-11-11
191223 / 3699522	Project / net462 / native	103871 / 103864	102035 / 102042	20:06:45-20:08:20
191223 / 3699490	Project / net10.0 / managed	104006 / 104012	101787 / 103536	20:07:46-20:09:12
191179 / 3700257	Package / net10.0 / native	103996 / 104007	103237 / 101710	20:50:50-20:52:14

Quarantine/ordinary log IDs: build 191223 net462 83/78, net10.0 80/79;
build 191179 native net10.0 351/347. Result pages reconcile with run totals.

Coverage boundaries: no individually published Linux quarantine or
Package/net462 results were available. Fake connections do not exercise SQL,
SNI or enclaves. The controlled regression demonstrates premature completion,
not an exact replay of the historical eight-worker scheduling.

Copilot

🔵 Needs a closer look

Trusted policy revisions, current PR reviewer feedback, and required scoped Azure DevOps validation are unavailable, so reported local passes cannot establish the repair’s validity on the affected CI image.

No open issues 🎉

What changed in this PR

Corrects the pool instrumentation test’s legacy checkout wait from the harness’s 15-millisecond default to the intended 30-second budget, without changing production behavior.

Changes:

Shares the 30-second budget between pool configuration and caller timeout while preserving other tests’ defaults.
Adds a held-slot contention regression for both pool implementations, checking completion and balanced counters.
Retains flaky and adds probation, preserving the existing concurrency workload and assertions.

File	Description
src/Microsoft.Data.SqlClient/tests/UnitTests/ConnectionPool/DbConnectionPoolInstrumentationTest.cs	Aligns checkout wait budgets, adds contention coverage, and marks the repaired theory for probation.

_{Review effort: Balanced}

codecov · 2026-11-11T17:57:10Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.51%. Comparing base (d8a60de) to head (43af401).
⚠️ Report is 11 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5039      +/-   ##
==========================================
+ Coverage   68.74%   72.51%   +3.76%     
==========================================
  Files         314      314              
  Lines       45849    71135   +25286     
==========================================
+ Hits        31519    51580   +20061     
- Misses      14330    19555    +5225

Flag	Coverage Δ
CI-SqlClient	`?`
sqlclient-pr	`72.51% <ø> (?)`

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Copilot

🔵 Needs a closer look

Required trusted immutable review-policy references were not supplied, and current-head CI is still pending for the timing-sensitive test repair.

No open issues 🎉

_{Review effort: Balanced}

Align concurrent instrumentation test pool wait budget

786757a

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Copilot AI balanced review requested due to automatic review settings November 11, 2026 17:06

github-project-automation Bot added this to SqlClient Board Nov 11, 2026

github-project-automation Bot moved this to To triage in SqlClient Board Nov 11, 2026

Copilot started reviewing on behalf of mdaigle November 11, 2026 17:07

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mdaigle added this to the 8.1.0-preview1 milestone Nov 11, 2026

mdaigle marked this pull request as ready for review November 11, 2026 21:19

mdaigle requested a review from a team as a code owner November 11, 2026 21:19

github-actions Bot assigned cheenamalhotra and saurabh500 Nov 11, 2026

This was referenced Nov 12, 2026

Quarantine intermittent split-packet full-header test #5047

Merged

Quarantine intermittent MARS split-packet test #5065

Open

mdaigle added the Area\Tests Issues that are targeted to tests or test projects label Nov 13, 2026

mdaigle commented Nov 13, 2026

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Comment thread ...crosoft.Data.SqlClient/tests/UnitTests/ConnectionPool/DbConnectionPoolInstrumentationTest.cs Resolved

Use one pool wait budget for all instrumentation tests

43af401

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Copilot AI balanced review requested due to automatic review settings November 13, 2026 18:20

Copilot started reviewing on behalf of mdaigle November 13, 2026 18:20

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Fix pool instrumentation checkout test wait budget - #5039

Fix pool instrumentation checkout test wait budget#5039
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