[dudikeleti]

Summary of changes

• Remove the Dynamic Instrumentation adaptive cache (tracer/src/Datadog.Trace/Debugger/Caching/: ConcurrentAdaptiveCache, its eviction policies, memory and environment checkers) and its tests.
• Remove WindowsMemoryInfo.TryGetAvailablePhysicalMemory and its test. Its only caller was the deleted memory checker.

Reason for change

• After [Debugger] Make redaction cache hits lock-free and allocation-free #9538, Redaction no longer uses ConcurrentAdaptiveCache, and nothing else did. Each cache instance also started a background cleanup task, so keeping the type around invites reuse of a design that took a process-wide write lock on every hit.

Implementation details

• Deletion only: 16 files, about 1900 lines.
• git grep at the head finds no references to the removed types, the Datadog.Trace.Debugger.Caching namespace or TryGetAvailablePhysicalMemory, apart from historical docs/CHANGELOG.md entries.
• Regenerating the trimming file (CompileManagedLoader CreateTrimmingFile) produces no change to Datadog.Trace.Trimming.xml.
• WindowsMemoryInfo.TryGetMemoryLoadRatio stays; SystemMemorySource still uses it.

Test coverage

• dotnet build -c Release of Datadog.Trace for net461, netstandard2.0, netcoreapp3.1 and net6.0: no warnings.
• dotnet test tracer/test/Datadog.Trace.Tests/Datadog.Trace.Tests.csproj -c Release -f net10.0 --filter "FullyQualifiedName~Datadog.Trace.Tests.Debugger": 868 passed, 2 skipped.
• Same with -f net48: 831 passed, 29 skipped.

Other details

• Stacked on [Debugger] Make redaction cache hits lock-free and allocation-free #9538.

[pr-commenter]

Benchmarks

Benchmark execution time: 2026-10-28 11:04:36

Comparing candidate commit 134c6d4 in PR branch dudik/chore/remove-debugger-adaptive-cache with baseline commit 5769328 in branch master.

📊 Benchmarking dashboard

Found 0 performance improvements and 3 performance regressions! Performance is the same for 68 metrics, 1 unstable metrics, 11 known flaky benchmarks, 115 flaky benchmarks without significant changes.

Explanation

This is an A/B test comparing a candidate commit's performance against that of a baseline commit. Performance changes are noted in the tables below as:

• 🟩 = significantly better candidate vs. baseline
• 🟥 = significantly worse candidate vs. baseline

We compute a confidence interval (CI) over the relative difference of means between metrics from the candidate and baseline commits, considering the baseline as the reference.

If the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD), the change is considered significant.

Feel free to reach out to #apm-benchmarking-platform on Slack if you have any questions.

More details about the CI and significant changes

You can imagine this CI as a range of values that is likely to contain the true difference of means between the candidate and baseline commits.

CIs of the difference of means are often centered around 0%, because often changes are not that big:

---------------------------------(------|---^--------)-------------------------------->
                              -0.6%    0%  0.3%     +1.2%
                                 |          |        |
         lower bound of the CI --'          |        |
sample mean (center of the CI) -------------'        |
         upper bound of the CI ----------------------'

As described above, a change is considered significant if the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD).

For instance, for an execution time metric, this confidence interval indicates a significantly worse performance:

----------------------------------------|---------|---(---------^---------)---------->
                                       0%        1%  1.3%      2.2%      3.1%
                                                  |   |         |         |
       significant impact threshold --------------'   |         |         |
                      lower bound of CI --------------'         |         |
       sample mean (center of the CI) --------------------------'         |
                      upper bound of CI ----------------------------------'

scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TracerBenchmark.StartActiveSpan net6.0

• 🟥 throughput [-49608.579op/s; -34186.830op/s] or [-18.789%; -12.948%]

scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TracerBenchmark.StartRootSpan net472

• 🟥 throughput [-13675.367op/s; -12237.560op/s] or [-7.360%; -6.586%]

scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TracerBenchmark.StartSpan net472

• 🟥 throughput [-12709.858op/s; -11559.416op/s] or [-6.869%; -6.248%]

Unstable benchmarks

These benchmarks have a confidence interval too wide to call a change; treat them as noise rather than signal.

scenario:Benchmarks.Trace.HttpClientBenchmark.SendAsync netcoreapp3.1

• unstable execution_time [-28.582ms; -7.694ms] or [-14.280%; -3.844%]

Known flaky benchmarks

These benchmarks are marked as flaky and will not trigger a failure. Modify FLAKY_BENCHMARKS_REGEX to control which benchmarks are marked as flaky.

scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_SetAttributes_Sampled net6.0

• 🟥 throughput [-18912.244op/s; -12285.442op/s] or [-8.818%; -5.728%]

scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_UpdateName_Sampled net472

• 🟥 throughput [-15358.323op/s; -13723.903op/s] or [-7.895%; -7.055%]

scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_UpdateName_Sampled net6.0

• 🟥 throughput [-64313.989op/s; -48934.117op/s] or [-23.690%; -18.025%]

scenario:Benchmarks.Trace.AspNetCoreBenchmark.SendRequest net6.0

• unstable execution_time [-87.318ms; -17.676ms] or [-17.225%; -3.487%]

scenario:Benchmarks.Trace.AspNetCoreBenchmark.SendRequest netcoreapp3.1

• unstable execution_time [-92.002ms; -6.910ms] or [-20.287%; -1.524%]

scenario:Benchmarks.Trace.CIVisibilityProtocolWriterBenchmark.WriteAndFlushEnrichedTraces net472

• unstable execution_time [-104.471ms; -27.160ms] or [-18.483%; -4.805%]

scenario:Benchmarks.Trace.CIVisibilityProtocolWriterBenchmark.WriteAndFlushEnrichedTraces netcoreapp3.1

• 🟥 allocated_mem [+2.127KB; +2.131KB] or [+5.002%; +5.010%]

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSliceWithPool netcoreapp3.1

• unstable execution_time [-276.265µs; -66.963µs] or [-14.526%; -3.521%]
• unstable throughput [+35.427op/s; +169.715op/s] or [+6.731%; +32.246%]

scenario:Benchmarks.Trace.CharSliceBenchmark.OriginalCharSlice netcoreapp3.1

• unstable execution_time [-279.752µs; +210.172µs] or [-7.189%; +5.401%]
• unstable throughput [-27.349op/s; +8.909op/s] or [-10.179%; +3.316%]

scenario:Benchmarks.Trace.Iast.StringAspectsBenchmark.StringConcatAspectBenchmark net6.0

• 🟩 allocated_mem [-58.580KB; -58.560KB] or [-18.744%; -18.738%]
• unstable execution_time [-119.832µs; -22.368µs] or [-20.635%; -3.852%]
• unstable throughput [+25.828op/s; +274.996op/s] or [+1.409%; +14.999%]

scenario:Benchmarks.Trace.Iast.StringAspectsBenchmark.StringConcatBenchmark netcoreapp3.1

• unstable execution_time [-5.748µs; +1.248µs] or [-10.238%; +2.222%]

Known flaky benchmarks without significant changes:

• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_AddEvent_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_AddEvent_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_AddEvent_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_GetContext_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_GetContext_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_GetContext_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_SetAttributes_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_SetAttributes_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_SetStatus_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_SetStatus_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_SetStatus_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_UpdateName_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.ActivityBenchmark.StartSpan_UpdateName_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_AddEvent_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_AddEvent_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_AddEvent_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_GetContext_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_GetContext_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_GetContext_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_RecordException_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_RecordException_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_RecordException_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_SetAttributes_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_SetAttributes_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_SetAttributes_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_SetStatus_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_SetStatus_Sampled net6.0
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_SetStatus_Sampled netcoreapp3.1
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_UpdateName_Sampled net472
• scenario:Benchmarks.OpenTelemetry.InstrumentedApi.Trace.TelemetrySpanBenchmark.StartSpan_UpdateName_Sampled netcoreapp3.1
• scenario:Benchmarks.Trace.ActivityBenchmark.StartStopWithChild net472
• scenario:Benchmarks.Trace.ActivityBenchmark.StartStopWithChild net6.0
• scenario:Benchmarks.Trace.ActivityBenchmark.StartStopWithChild netcoreapp3.1
• scenario:Benchmarks.Trace.AgentWriterBenchmark.WriteAndFlushEnrichedTraces net472
• scenario:Benchmarks.Trace.AgentWriterBenchmark.WriteAndFlushEnrichedTraces net6.0
• scenario:Benchmarks.Trace.AgentWriterBenchmark.WriteAndFlushEnrichedTraces netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleMoreComplexBody net472
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleMoreComplexBody net6.0
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleMoreComplexBody netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody net472
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody net6.0
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorMoreComplexBody net472
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorMoreComplexBody net6.0
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorMoreComplexBody netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorSimpleBody net472
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorSimpleBody net6.0
• scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorSimpleBody netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeArgs net472
• scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeArgs net6.0
• scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeArgs netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeLegacyArgs net472
• scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeLegacyArgs net6.0
• scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeLegacyArgs netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecWafBenchmark.RunWafRealisticBenchmark net472
• scenario:Benchmarks.Trace.Asm.AppSecWafBenchmark.RunWafRealisticBenchmark net6.0
• scenario:Benchmarks.Trace.Asm.AppSecWafBenchmark.RunWafRealisticBenchmark netcoreapp3.1
• scenario:Benchmarks.Trace.Asm.AppSecWafBenchmark.RunWafRealisticBenchmarkWithAttack net472
• scenario:Benchmarks.Trace.Asm.AppSecWafBenchmark.RunWafRealisticBenchmarkWithAttack net6.0
• scenario:Benchmarks.Trace.Asm.AppSecWafBenchmark.RunWafRealisticBenchmarkWithAttack netcoreapp3.1
• scenario:Benchmarks.Trace.AspNetCoreBenchmark.SendRequest net472
• scenario:Benchmarks.Trace.CIVisibilityProtocolWriterBenchmark.WriteAndFlushEnrichedTraces net6.0
• scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice net472
• scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice net6.0
• scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice netcoreapp3.1
• scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSliceWithPool net472
• scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSliceWithPool net6.0
• scenario:Benchmarks.Trace.CharSliceBenchmark.OriginalCharSlice net472
• scenario:Benchmarks.Trace.CharSliceBenchmark.OriginalCharSlice net6.0
• scenario:Benchmarks.Trace.ElasticsearchBenchmark.CallElasticsearch net472
• scenario:Benchmarks.Trace.ElasticsearchBenchmark.CallElasticsearch net6.0
• scenario:Benchmarks.Trace.ElasticsearchBenchmark.CallElasticsearch netcoreapp3.1
• scenario:Benchmarks.Trace.ElasticsearchBenchmark.CallElasticsearchAsync net472
• scenario:Benchmarks.Trace.ElasticsearchBenchmark.CallElasticsearchAsync net6.0
• scenario:Benchmarks.Trace.ElasticsearchBenchmark.CallElasticsearchAsync netcoreapp3.1
• scenario:Benchmarks.Trace.GraphQLBenchmark.ExecuteAsync net472
• scenario:Benchmarks.Trace.GraphQLBenchmark.ExecuteAsync net6.0
• scenario:Benchmarks.Trace.GraphQLBenchmark.ExecuteAsync netcoreapp3.1
• scenario:Benchmarks.Trace.ILoggerBenchmark.EnrichedLog net472
• scenario:Benchmarks.Trace.ILoggerBenchmark.EnrichedLog net6.0
• scenario:Benchmarks.Trace.ILoggerBenchmark.EnrichedLog netcoreapp3.1
• scenario:Benchmarks.Trace.Iast.StringAspectsBenchmark.StringConcatAspectBenchmark net472
• scenario:Benchmarks.Trace.Iast.StringAspectsBenchmark.StringConcatAspectBenchmark netcoreapp3.1
• scenario:Benchmarks.Trace.Iast.StringAspectsBenchmark.StringConcatBenchmark net472
• scenario:Benchmarks.Trace.Iast.StringAspectsBenchmark.StringConcatBenchmark net6.0
• scenario:Benchmarks.Trace.Log4netBenchmark.EnrichedLog net472
• scenario:Benchmarks.Trace.Log4netBenchmark.EnrichedLog net6.0
• scenario:Benchmarks.Trace.Log4netBenchmark.EnrichedLog netcoreapp3.1
• scenario:Benchmarks.Trace.RedisBenchmark.SendReceive net472
• scenario:Benchmarks.Trace.RedisBenchmark.SendReceive net6.0
• scenario:Benchmarks.Trace.RedisBenchmark.SendReceive netcoreapp3.1
• scenario:Benchmarks.Trace.SerilogBenchmark.EnrichedLog net472
• scenario:Benchmarks.Trace.SerilogBenchmark.EnrichedLog net6.0
• scenario:Benchmarks.Trace.SerilogBenchmark.EnrichedLog netcoreapp3.1
• scenario:Benchmarks.Trace.SingleSpanAspNetCoreBenchmark.SingleSpanAspNetCore net472
• scenario:Benchmarks.Trace.SingleSpanAspNetCoreBenchmark.SingleSpanAspNetCore net6.0
• scenario:Benchmarks.Trace.SingleSpanAspNetCoreBenchmark.SingleSpanAspNetCore netcoreapp3.1
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishScope net472
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishScope net6.0
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishScope netcoreapp3.1
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishSpan net472
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishSpan net6.0
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishSpan netcoreapp3.1
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishTwoScopes net472
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishTwoScopes net6.0
• scenario:Benchmarks.Trace.SpanBenchmark.StartFinishTwoScopes netcoreapp3.1
• scenario:Benchmarks.Trace.TraceAnnotationsBenchmark.RunOnMethodBegin net472
• scenario:Benchmarks.Trace.TraceAnnotationsBenchmark.RunOnMethodBegin net6.0
• scenario:Benchmarks.Trace.TraceAnnotationsBenchmark.RunOnMethodBegin netcoreapp3.1

[dd-trace-dotnet-ci-bot]

Execution-Time Benchmarks Report ⏱️

Execution-time results for samples comparing This PR (9543) and master.

✅ No regressions detected

📄 View the full report (charts + all metrics) →