Consolidate Helix shards for quick test assemblies via MethodLimitMultiplier#54115
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Consolidate Helix shards for quick test assemblies via MethodLimitMultiplier#54115MichaelSimons wants to merge 4 commits intodotnet:mainfrom
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Add per-assembly MethodLimitMultiplier metadata support to reduce wasted
Helix compute on assemblies whose shards all complete very quickly. The
multiplier increases the methods-per-shard threshold, producing fewer but
larger work items and reducing per-item setup overhead.
Applied to three assembly groups:
- Microsoft.CodeAnalysis.NetAnalyzers (x5)
- Microsoft.TemplateEngine.* / TemplateSearch.* (x10)
- Microsoft.DotNet.Api{Compatibility,Diff,SymbolExtensions} (x5)
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
TE assemblies are already single-shard on FullFramework at x10. The x20 bump collapses the remaining 2-shard assemblies on TestBuild legs (Cli.UnitTests, Core.UnitTests, Orchestrator) to single shards. Api group bumped to x10 and expanded to include GenAPI.Tests and PackageValidation.Tests for additional shard savings. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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This was referenced Apr 28, 2026
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This was referenced Apr 29, 2026
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Summary
Adds a
MethodLimitMultipliermetadata option forSDKCustomXUnitProjectitems to consolidate Helix test shards for assemblies that produce many very short work items. This reduces per-item overhead (payload download, setup, teardown) and makes us better citizens of the shared Helix queues.How it works
AssemblySchedulerpartitions each test assembly into shards based on amethodLimitthreshold (default 16, or 32 for FullFramework).MethodLimitMultipliersimply multiplies that threshold, producing fewer, larger shards. It is set via MSBuild item metadata inUnitTests.proj— no new config files.Changes
SDKCustomCreateXUnitWorkItemsWithTestExclusion.cs— Reads optionalMethodLimitMultipliermetadata; warns on invalid valuesUnitTests.proj— Applies multipliers to three assembly groups:Results
Linux x64
Windows x64
macOS x64
FullFramework Windows
Overall
¹ TemplateEngine and Api assemblies are now at one shard per assembly — the minimum possible without cross-assembly consolidation. Further shard reduction for these groups would require changes to the Helix sharding model itself.