Refactor Azure Functions instrumentation before #7628 by lucaspimentel · Pull Request #8079 · DataDog/dd-trace-dotnet

lucaspimentel · 2026-01-16T21:59:02Z

Summary of changes

Refactor Azure Functions instrumentation code as a precursor to #7628.

Reason for change

The changes in #7628 were building up, so I decided to split them into two PRs. This PR is mostly cleanup and refactoring. No functional changes.

Implementation details

Environment detection helpers (EnvironmentHelpers)

Added IsAzureFunctionsIsolated() - detects isolated worker runtime
Added GetAzureFunctionsWorkerRuntime() - retrieves worker runtime value
Added GetAzureFunctionsExtensionVersion() - retrieves extension version
Refactored IsRunningInAzureFunctionsHost() to use new helpers

Diagnostic observer initialization (Instrumentation)

Extracted GetAspNetCoreDiagnosticObserver()
Extracted SkipAspNetCoreDiagnosticObserver()

Azure Functions instrumentation cleanup (AzureFunctionsCommon)

Renamed parameter context to functionContext for clarity and consistency
Made CreateIsolatedFunctionScope() private
Formatting: improved comment alignment and whitespace
Changed if to switch for trigger type handling

ASP.NET Core tracking key rename

Renamed HttpContextItemsKey to HttpContextTrackingKey across all usages (will add another key in next PR, needed to distinguish them since they are both "item keys")

Test coverage

No new tests added - this is a refactoring/cleanup PR with no functional changes. Existing Azure Functions tests provide coverage.

Other details

Precursor to #7628 - Fix span parenting for isolated Azure Functions using ASP.NET Core integration

dd-trace-dotnet-ci-bot · 2026-01-20T22:41:52Z

Execution-Time Benchmarks Report ⏱️

Execution-time results for samples comparing This PR (8079) and master.

⚠️ Potential regressions detected

FakeDbCommand

Metric	Master (Mean ± 95% CI)	Current (Mean ± 95% CI)	Change	Status
.NET Framework 4.8 - Baseline
duration	68.48 ± (68.49 - 68.75) ms	77.75 ± (77.70 - 78.09) ms	+13.5%	❌⬆️
.NET Framework 4.8 - Bailout
duration	72.33 ± (72.20 - 72.41) ms	82.63 ± (82.45 - 82.87) ms	+14.2%	❌⬆️
.NET Framework 4.8 - CallTarget+Inlining+NGEN
duration	1005.41 ± (1014.39 - 1025.33) ms	1087.91 ± (1088.85 - 1098.03) ms	+8.2%	❌⬆️

Full Metrics Comparison

FakeDbCommand

Metric	Master (Mean ± 95% CI)	Current (Mean ± 95% CI)	Change	Status
.NET Framework 4.8 - Baseline
duration	68.48 ± (68.49 - 68.75) ms	77.75 ± (77.70 - 78.09) ms	+13.5%	❌⬆️
.NET Framework 4.8 - Bailout
duration	72.33 ± (72.20 - 72.41) ms	82.63 ± (82.45 - 82.87) ms	+14.2%	❌⬆️
.NET Framework 4.8 - CallTarget+Inlining+NGEN
duration	1005.41 ± (1014.39 - 1025.33) ms	1087.91 ± (1088.85 - 1098.03) ms	+8.2%	❌⬆️
.NET Core 3.1 - Baseline
process.internal_duration_ms	21.86 ± (21.84 - 21.89) ms	24.14 ± (24.09 - 24.20) ms	+10.4%	✅⬆️
process.time_to_main_ms	79.07 ± (78.91 - 79.24) ms	92.57 ± (92.35 - 92.79) ms	+17.1%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	10.91 ± (10.91 - 10.92) MB	10.91 ± (10.90 - 10.91) MB	-0.1%	✅
runtime.dotnet.threads.count	12 ± (12 - 12)	12 ± (12 - 12)	+0.0%	✅
.NET Core 3.1 - Bailout
process.internal_duration_ms	21.82 ± (21.80 - 21.84) ms	23.88 ± (23.83 - 23.94) ms	+9.5%	✅⬆️
process.time_to_main_ms	80.23 ± (80.12 - 80.34) ms	93.16 ± (92.90 - 93.41) ms	+16.1%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	10.95 ± (10.95 - 10.96) MB	10.97 ± (10.96 - 10.97) MB	+0.2%	✅⬆️
runtime.dotnet.threads.count	13 ± (13 - 13)	13 ± (13 - 13)	+0.0%	✅
.NET Core 3.1 - CallTarget+Inlining+NGEN
process.internal_duration_ms	242.15 ± (238.49 - 245.81) ms	240.73 ± (237.06 - 244.39) ms	-0.6%	✅
process.time_to_main_ms	468.08 ± (467.57 - 468.60) ms	523.96 ± (523.16 - 524.76) ms	+11.9%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	48.34 ± (48.31 - 48.37) MB	48.26 ± (48.23 - 48.29) MB	-0.2%	✅
runtime.dotnet.threads.count	28 ± (28 - 28)	28 ± (28 - 28)	-0.2%	✅
.NET 6 - Baseline
process.internal_duration_ms	20.71 ± (20.68 - 20.74) ms	22.84 ± (22.78 - 22.90) ms	+10.3%	✅⬆️
process.time_to_main_ms	68.33 ± (68.24 - 68.43) ms	81.18 ± (80.98 - 81.39) ms	+18.8%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	10.62 ± (10.61 - 10.62) MB	10.64 ± (10.64 - 10.64) MB	+0.2%	✅⬆️
runtime.dotnet.threads.count	10 ± (10 - 10)	10 ± (10 - 10)	+0.0%	✅
.NET 6 - Bailout
process.internal_duration_ms	20.62 ± (20.60 - 20.64) ms	22.56 ± (22.50 - 22.62) ms	+9.4%	✅⬆️
process.time_to_main_ms	69.59 ± (69.53 - 69.66) ms	81.96 ± (81.75 - 82.18) ms	+17.8%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	10.73 ± (10.72 - 10.74) MB	10.75 ± (10.74 - 10.75) MB	+0.2%	✅⬆️
runtime.dotnet.threads.count	11 ± (11 - 11)	11 ± (11 - 11)	+0.0%	✅
.NET 6 - CallTarget+Inlining+NGEN
process.internal_duration_ms	248.52 ± (246.84 - 250.21) ms	235.62 ± (231.31 - 239.93) ms	-5.2%	✅
process.time_to_main_ms	446.84 ± (446.41 - 447.27) ms	497.58 ± (496.82 - 498.35) ms	+11.4%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	49.26 ± (49.24 - 49.29) MB	49.02 ± (49.00 - 49.04) MB	-0.5%	✅
runtime.dotnet.threads.count	28 ± (28 - 28)	28 ± (28 - 28)	+0.0%	✅⬆️
.NET 8 - Baseline
process.internal_duration_ms	18.84 ± (18.82 - 18.87) ms	20.55 ± (20.50 - 20.60) ms	+9.0%	✅⬆️
process.time_to_main_ms	67.56 ± (67.44 - 67.68) ms	78.66 ± (78.45 - 78.87) ms	+16.4%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	7.66 ± (7.65 - 7.66) MB	7.67 ± (7.67 - 7.68) MB	+0.2%	✅⬆️
runtime.dotnet.threads.count	10 ± (10 - 10)	10 ± (10 - 10)	+0.0%	✅
.NET 8 - Bailout
process.internal_duration_ms	18.87 ± (18.85 - 18.89) ms	20.59 ± (20.53 - 20.65) ms	+9.1%	✅⬆️
process.time_to_main_ms	68.62 ± (68.56 - 68.67) ms	79.73 ± (79.53 - 79.93) ms	+16.2%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	7.75 ± (7.73 - 7.76) MB	7.72 ± (7.71 - 7.74) MB	-0.3%	✅
runtime.dotnet.threads.count	11 ± (11 - 11)	11 ± (11 - 11)	+0.0%	✅
.NET 8 - CallTarget+Inlining+NGEN
process.internal_duration_ms	178.45 ± (177.56 - 179.34) ms	197.83 ± (197.00 - 198.66) ms	+10.9%	✅⬆️
process.time_to_main_ms	429.97 ± (429.42 - 430.51) ms	474.89 ± (473.88 - 475.91) ms	+10.4%	✅⬆️
runtime.dotnet.exceptions.count	0 ± (0 - 0)	0 ± (0 - 0)	+0.0%	✅
runtime.dotnet.mem.committed	36.51 ± (36.48 - 36.54) MB	36.97 ± (36.93 - 37.02) MB	+1.3%	✅⬆️
runtime.dotnet.threads.count	27 ± (27 - 27)	27 ± (27 - 27)	-0.2%	✅

HttpMessageHandler

Metric	Master (Mean ± 95% CI)	Current (Mean ± 95% CI)	Change	Status
.NET Framework 4.8 - Baseline
duration	192.09 ± (192.01 - 192.81) ms	194.14 ± (193.87 - 194.54) ms	+1.1%	✅⬆️
.NET Framework 4.8 - Bailout
duration	195.01 ± (194.95 - 195.49) ms	198.71 ± (198.41 - 198.97) ms	+1.9%	✅⬆️
.NET Framework 4.8 - CallTarget+Inlining+NGEN
duration	1109.23 ± (1114.44 - 1123.54) ms	1131.72 ± (1132.16 - 1139.61) ms	+2.0%	✅⬆️
.NET Core 3.1 - Baseline
process.internal_duration_ms	186.98 ± (186.62 - 187.34) ms	189.88 ± (189.44 - 190.32) ms	+1.5%	✅⬆️
process.time_to_main_ms	80.37 ± (80.14 - 80.60) ms	81.83 ± (81.61 - 82.05) ms	+1.8%	✅⬆️
runtime.dotnet.exceptions.count	3 ± (3 - 3)	3 ± (3 - 3)	+0.0%	✅
runtime.dotnet.mem.committed	16.12 ± (16.09 - 16.15) MB	16.03 ± (16.01 - 16.06) MB	-0.6%	✅
runtime.dotnet.threads.count	20 ± (20 - 20)	20 ± (19 - 20)	-0.1%	✅
.NET Core 3.1 - Bailout
process.internal_duration_ms	185.55 ± (185.30 - 185.81) ms	190.20 ± (189.75 - 190.66) ms	+2.5%	✅⬆️
process.time_to_main_ms	81.65 ± (81.50 - 81.81) ms	83.48 ± (83.24 - 83.71) ms	+2.2%	✅⬆️
runtime.dotnet.exceptions.count	3 ± (3 - 3)	3 ± (3 - 3)	+0.0%	✅
runtime.dotnet.mem.committed	16.14 ± (16.12 - 16.17) MB	16.11 ± (16.09 - 16.13) MB	-0.2%	✅
runtime.dotnet.threads.count	21 ± (20 - 21)	21 ± (20 - 21)	+0.2%	✅⬆️
.NET Core 3.1 - CallTarget+Inlining+NGEN
process.internal_duration_ms	432.33 ± (429.49 - 435.17) ms	427.91 ± (424.68 - 431.14) ms	-1.0%	✅
process.time_to_main_ms	471.32 ± (470.78 - 471.86) ms	485.49 ± (484.31 - 486.67) ms	+3.0%	✅⬆️
runtime.dotnet.exceptions.count	3 ± (3 - 3)	3 ± (3 - 3)	+0.0%	✅
runtime.dotnet.mem.committed	58.66 ± (58.54 - 58.77) MB	58.83 ± (58.72 - 58.95) MB	+0.3%	✅⬆️
runtime.dotnet.threads.count	29 ± (29 - 29)	29 ± (29 - 30)	+0.2%	✅⬆️
.NET 6 - Baseline
process.internal_duration_ms	191.71 ± (191.30 - 192.12) ms	195.40 ± (194.94 - 195.86) ms	+1.9%	✅⬆️
process.time_to_main_ms	70.10 ± (69.93 - 70.27) ms	71.82 ± (71.60 - 72.04) ms	+2.5%	✅⬆️
runtime.dotnet.exceptions.count	4 ± (4 - 4)	4 ± (4 - 4)	+0.0%	✅
runtime.dotnet.mem.committed	16.10 ± (15.96 - 16.24) MB	16.36 ± (16.33 - 16.39) MB	+1.6%	✅⬆️
runtime.dotnet.threads.count	18 ± (18 - 18)	19 ± (19 - 19)	+5.3%	✅⬆️
.NET 6 - Bailout
process.internal_duration_ms	190.06 ± (189.84 - 190.29) ms	192.55 ± (192.21 - 192.89) ms	+1.3%	✅⬆️
process.time_to_main_ms	70.63 ± (70.53 - 70.74) ms	72.12 ± (71.97 - 72.27) ms	+2.1%	✅⬆️
runtime.dotnet.exceptions.count	4 ± (4 - 4)	4 ± (4 - 4)	+0.0%	✅
runtime.dotnet.mem.committed	15.89 ± (15.73 - 16.04) MB	16.08 ± (15.94 - 16.22) MB	+1.2%	✅⬆️
runtime.dotnet.threads.count	19 ± (19 - 19)	20 ± (19 - 20)	+3.4%	✅⬆️
.NET 6 - CallTarget+Inlining+NGEN
process.internal_duration_ms	443.82 ± (441.03 - 446.61) ms	446.23 ± (442.75 - 449.71) ms	+0.5%	✅⬆️
process.time_to_main_ms	447.88 ± (447.42 - 448.35) ms	456.41 ± (455.86 - 456.96) ms	+1.9%	✅⬆️
runtime.dotnet.exceptions.count	4 ± (4 - 4)	4 ± (4 - 4)	+0.0%	✅
runtime.dotnet.mem.committed	58.95 ± (58.84 - 59.07) MB	58.72 ± (58.58 - 58.85) MB	-0.4%	✅
runtime.dotnet.threads.count	29 ± (29 - 29)	29 ± (29 - 29)	-0.1%	✅
.NET 8 - Baseline
process.internal_duration_ms	190.04 ± (189.63 - 190.45) ms	191.62 ± (191.30 - 191.95) ms	+0.8%	✅⬆️
process.time_to_main_ms	69.78 ± (69.62 - 69.94) ms	70.57 ± (70.37 - 70.77) ms	+1.1%	✅⬆️
runtime.dotnet.exceptions.count	4 ± (4 - 4)	4 ± (4 - 4)	+0.0%	✅
runtime.dotnet.mem.committed	11.81 ± (11.78 - 11.84) MB	11.71 ± (11.68 - 11.73) MB	-0.9%	✅
runtime.dotnet.threads.count	18 ± (18 - 18)	18 ± (18 - 18)	-0.0%	✅
.NET 8 - Bailout
process.internal_duration_ms	188.67 ± (188.39 - 188.96) ms	193.22 ± (192.74 - 193.70) ms	+2.4%	✅⬆️
process.time_to_main_ms	70.75 ± (70.61 - 70.90) ms	72.15 ± (71.98 - 72.32) ms	+2.0%	✅⬆️
runtime.dotnet.exceptions.count	4 ± (4 - 4)	4 ± (4 - 4)	+0.0%	✅
runtime.dotnet.mem.committed	11.87 ± (11.83 - 11.92) MB	11.75 ± (11.73 - 11.77) MB	-1.0%	✅
runtime.dotnet.threads.count	19 ± (18 - 19)	19 ± (19 - 19)	+2.9%	✅⬆️
.NET 8 - CallTarget+Inlining+NGEN
process.internal_duration_ms	364.01 ± (362.25 - 365.77) ms	368.08 ± (366.82 - 369.35) ms	+1.1%	✅⬆️
process.time_to_main_ms	434.84 ± (434.24 - 435.44) ms	438.13 ± (437.41 - 438.85) ms	+0.8%	✅⬆️
runtime.dotnet.exceptions.count	4 ± (4 - 4)	4 ± (4 - 4)	+0.0%	✅
runtime.dotnet.mem.committed	48.20 ± (48.16 - 48.24) MB	48.22 ± (48.18 - 48.26) MB	+0.0%	✅⬆️
runtime.dotnet.threads.count	29 ± (28 - 29)	29 ± (29 - 29)	+1.2%	✅⬆️

Comparison explanation

Execution-time benchmarks measure the whole time it takes to execute a program, and are intended to measure the one-off costs. Cases where the execution time results for the PR are worse than latest master results are highlighted in **red**. The following thresholds were used for comparing the execution times:

Welch test with statistical test for significance of 5%
Only results indicating a difference greater than 5% and 5 ms are considered.

Note that these results are based on a single point-in-time result for each branch. For full results, see the dashboard.

Graphs show the p99 interval based on the mean and StdDev of the test run, as well as the mean value of the run (shown as a diamond below the graph).

Duration charts

FakeDbCommand (.NET Framework 4.8)

gantt
    title Execution time (ms) FakeDbCommand (.NET Framework 4.8)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (78ms)  : 75, 81
    master - mean (69ms)  : 67, 70

    section Bailout
    This PR (8079) - mean (83ms)  : crit, 80, 85
    master - mean (72ms)  : 71, 73

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (1,093ms)  : crit, 1028, 1159
    master - mean (1,020ms)  : 939, 1101

FakeDbCommand (.NET Core 3.1)

gantt
    title Execution time (ms) FakeDbCommand (.NET Core 3.1)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (124ms)  : 120, 128
    master - mean (106ms)  : 104, 109

    section Bailout
    This PR (8079) - mean (124ms)  : crit, 121, 128
    master - mean (107ms)  : 106, 109

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (806ms)  : crit, 748, 864
    master - mean (740ms)  : 687, 794

FakeDbCommand (.NET 6)

gantt
    title Execution time (ms) FakeDbCommand (.NET 6)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (111ms)  : 107, 115
    master - mean (94ms)  : 92, 96

    section Bailout
    This PR (8079) - mean (111ms)  : crit, 108, 115
    master - mean (95ms)  : 94, 96

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (772ms)  : crit, 696, 847
    master - mean (722ms)  : 691, 753

FakeDbCommand (.NET 8)

gantt
    title Execution time (ms) FakeDbCommand (.NET 8)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (107ms)  : 103, 111
    master - mean (93ms)  : 90, 95

    section Bailout
    This PR (8079) - mean (108ms)  : crit, 106, 111
    master - mean (93ms)  : 92, 95

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (712ms)  : crit, 690, 733
    master - mean (636ms)  : 621, 650

HttpMessageHandler (.NET Framework 4.8)

gantt
    title Execution time (ms) HttpMessageHandler (.NET Framework 4.8)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (194ms)  : 191, 197
    master - mean (192ms)  : 188, 196

    section Bailout
    This PR (8079) - mean (199ms)  : 196, 201
    master - mean (195ms)  : 193, 198

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (1,136ms)  : 1083, 1189
    master - mean (1,119ms)  : 1052, 1186

HttpMessageHandler (.NET Core 3.1)

gantt
    title Execution time (ms) HttpMessageHandler (.NET Core 3.1)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (280ms)  : 273, 287
    master - mean (276ms)  : 270, 282

    section Bailout
    This PR (8079) - mean (283ms)  : 275, 290
    master - mean (275ms)  : 272, 278

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (947ms)  : 895, 998
    master - mean (930ms)  : 880, 980

HttpMessageHandler (.NET 6)

gantt
    title Execution time (ms) HttpMessageHandler (.NET 6)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (276ms)  : 269, 282
    master - mean (270ms)  : 265, 274

    section Bailout
    This PR (8079) - mean (273ms)  : 269, 276
    master - mean (269ms)  : 266, 272

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (930ms)  : 876, 984
    master - mean (916ms)  : 858, 974

HttpMessageHandler (.NET 8)

gantt
    title Execution time (ms) HttpMessageHandler (.NET 8)
    dateFormat  x
    axisFormat %Q
    todayMarker off
    section Baseline
    This PR (8079) - mean (272ms)  : 266, 278
    master - mean (269ms)  : 262, 276

    section Bailout
    This PR (8079) - mean (275ms)  : 266, 284
    master - mean (269ms)  : 264, 274

    section CallTarget+Inlining+NGEN
    This PR (8079) - mean (839ms)  : 823, 855
    master - mean (832ms)  : 809, 855

pr-commenter · 2026-01-22T00:18:12Z

Benchmarks

Benchmark execution time: 2026-01-26 15:16:50

Comparing candidate commit 19c86a2 in PR branch lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup with baseline commit e62315b in branch master.

Found 12 performance improvements and 8 performance regressions! Performance is the same for 155 metrics, 17 unstable metrics.

scenario:Benchmarks.Trace.ActivityBenchmark.StartStopWithChild netcoreapp3.1

🟩 execution_time [-14.501ms; -11.526ms] or [-7.087%; -5.633%]

scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody net6.0

🟩 execution_time [-20.914ms; -14.927ms] or [-9.570%; -6.831%]

scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody netcoreapp3.1

🟩 execution_time [-24.640ms; -18.182ms] or [-11.450%; -8.449%]

scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorSimpleBody net6.0

🟥 execution_time [+16.390ms; +20.965ms] or [+8.196%; +10.484%]
🟩 throughput [+147219.592op/s; +218285.392op/s] or [+5.026%; +7.452%]

scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeLegacyArgs net6.0

🟩 execution_time [-28.910ms; -28.634ms] or [-14.231%; -14.095%]

scenario:Benchmarks.Trace.CIVisibilityProtocolWriterBenchmark.WriteAndFlushEnrichedTraces net472

🟥 execution_time [+18.811ms; +24.000ms] or [+9.632%; +12.289%]

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

🟥 throughput [-241.089op/s; -125.178op/s] or [-16.062%; -8.340%]

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice net472

🟥 execution_time [+142.258µs; +146.235µs] or [+7.412%; +7.619%]
🟥 throughput [-36.921op/s; -35.921op/s] or [-7.086%; -6.894%]

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice net6.0

🟩 execution_time [-160.508µs; -154.012µs] or [-10.370%; -9.951%]
🟩 throughput [+71.634op/s; +74.496op/s] or [+11.087%; +11.530%]

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSliceWithPool net6.0

🟩 execution_time [-85.701µs; -81.419µs] or [-7.553%; -7.176%]
🟩 throughput [+68.241op/s; +71.910op/s] or [+7.743%; +8.159%]

scenario:Benchmarks.Trace.GraphQLBenchmark.ExecuteAsync net472

🟩 throughput [+21108.945op/s; +24684.096op/s] or [+5.599%; +6.547%]

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

🟥 throughput [-594.876op/s; -393.036op/s] or [-26.265%; -17.353%]

scenario:Benchmarks.Trace.SingleSpanAspNetCoreBenchmark.SingleSpanAspNetCore netcoreapp3.1

🟥 throughput [-16147997.777op/s; -15008517.434op/s] or [-6.699%; -6.226%]

scenario:Benchmarks.Trace.SpanBenchmark.StartFinishScope netcoreapp3.1

🟩 execution_time [-16.072ms; -10.800ms] or [-7.633%; -5.129%]

scenario:Benchmarks.Trace.SpanBenchmark.StartFinishSpan netcoreapp3.1

🟩 execution_time [-18.770ms; -13.492ms] or [-8.784%; -6.314%]

scenario:Benchmarks.Trace.SpanBenchmark.StartFinishTwoScopes net6.0

🟥 execution_time [+16.432ms; +20.066ms] or [+8.113%; +9.907%]

pablomartinezbernardo

LGTM!

pablomartinezbernardo · 2026-01-26T09:42:20Z

tracer/src/Datadog.Trace/ClrProfiler/Instrumentation.cs

-            var functionsWorkerRuntime = EnvironmentHelpers.GetEnvironmentVariable(PlatformKeys.AzureFunctions.FunctionsWorkerRuntime);
-
-            if (!string.IsNullOrEmpty(functionsExtensionVersion) && !string.IsNullOrEmpty(functionsWorkerRuntime))
+            if (!SkipAspNetCoreDiagnosticObserver())


Previously this was looking at FUNCTIONS_EXTENSION_VERSION and FUNCTIONS_WORKER_RUNTIME, and now it is doing EnvironmentHelpers.IsAzureFunctions() which adds WEBSITE_SITE_NAME to the check. Seems totally intended, just mentioning it because the PR says there are no functional changes and I'm not sure if this has other consequences

Good catch, thanks! I'll take a closer look.

Ahh, yes. In EnvironmentHelpers we also check WEBSITE_SITE_NAME which we didn't do here before. It shouldn't make any difference in practice (all 3 env vars should always be set). We only check for the additional env vars to be safe, I guess.

Simplify Azure Functions logic by introducing `IsAzureFunctionsIsolated` and refactoring worker runtime checks into reusable methods.

## Summary of changes Refactor Azure Functions instrumentation code as a precursor to #7628. ## Reason for change The changes in #7628 were building up, so I decided to split them into two PRs. This PR is mostly cleanup and refactoring. No functional changes. ## Implementation details **Environment detection helpers** (`EnvironmentHelpers`) - Added `IsAzureFunctionsIsolated()` - detects isolated worker runtime - Added `GetAzureFunctionsWorkerRuntime()` - retrieves worker runtime value - Added `GetAzureFunctionsExtensionVersion()` - retrieves extension version - Refactored `IsRunningInAzureFunctionsHost()` to use new helpers **Diagnostic observer initialization** (`Instrumentation`) - Extracted `GetAspNetCoreDiagnosticObserver()` - Extracted `SkipAspNetCoreDiagnosticObserver()` **Azure Functions instrumentation cleanup** (`AzureFunctionsCommon`) - Renamed parameter `context` to `functionContext` for clarity and consistency - Made `CreateIsolatedFunctionScope()` private - Formatting: improved comment alignment and whitespace - Changed `if` to `switch` for trigger type handling **ASP.NET Core tracking key rename** - Renamed `HttpContextItemsKey` to `HttpContextTrackingKey` across all usages (will add another key in next PR, needed to distinguish them since they are both "item keys") ## Test coverage No new tests added - this is a refactoring/cleanup PR with no functional changes. Existing Azure Functions tests provide coverage. ## Other details Precursor to #7628 - Fix span parenting for isolated Azure Functions using ASP.NET Core integration

lucaspimentel force-pushed the lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup branch 2 times, most recently from bdae1c7 to 67e423e Compare January 20, 2026 20:15

lucaspimentel changed the title ~~cleanup before apmsvls 58 azfunc host parenting~~ code cleanup/refactoring before #7628 Jan 20, 2026

lucaspimentel changed the title ~~code cleanup/refactoring before #7628~~ Refactor Azure Functions instrumentation for improved clarity Jan 20, 2026

lucaspimentel force-pushed the lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup branch 3 times, most recently from cb6304f to ddd2357 Compare January 20, 2026 21:40

lucaspimentel changed the title ~~Refactor Azure Functions instrumentation for improved clarity~~ Refactor Azure Functions instrumentation before #7628 Jan 21, 2026

lucaspimentel force-pushed the lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup branch from ddd2357 to a9b5436 Compare January 21, 2026 23:36

lucaspimentel marked this pull request as ready for review January 22, 2026 22:12

lucaspimentel requested review from a team as code owners January 22, 2026 22:12

lucaspimentel requested a review from apiarian-datadog January 22, 2026 22:12

lucaspimentel mentioned this pull request Jan 22, 2026

[DON'T MERGE][Azure Functions] Fix span parenting in isolated functions using ASP.NET Core integration #7628

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pablomartinezbernardo approved these changes Jan 26, 2026

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lucaspimentel added 8 commits January 26, 2026 09:33

Add IsAzureFunctionsIsolated and related helper methods

d8e8423

Simplify Azure Functions logic by introducing `IsAzureFunctionsIsolated` and refactoring worker runtime checks into reusable methods.

rename parameter context to functionContext

1d52612

make method private

70e8937

align comments

af66768

remove obsolete comments

beaa730

convert if to switch statement

bc94d55

small refactor to reduce nesting

b1607b6

add comment

313ce43

lucaspimentel added 4 commits January 26, 2026 09:33

add whitespace

3c53647

refactor Instrumentation.StartDiagnosticManager()

7515728

rename field HttpContextItemsKey to HttpContextTrackingKey

512f8df

add comments

19c86a2

lucaspimentel force-pushed the lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup branch from a9b5436 to 19c86a2 Compare January 26, 2026 14:33

lucaspimentel removed the request for review from apiarian-datadog January 27, 2026 20:52

zacharycmontoya approved these changes Jan 27, 2026

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lucaspimentel merged commit 3db9044 into master Jan 27, 2026
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lucaspimentel deleted the lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup branch January 27, 2026 21:27

github-actions bot added this to the vNext-v3 milestone Jan 27, 2026

NachoEchevarria added the area:serverless label Feb 9, 2026

lucaspimentel mentioned this pull request Feb 17, 2026

[tracing] Create and reparent span for Azure API Management #7806

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Refactor Azure Functions instrumentation before #7628#8079

Refactor Azure Functions instrumentation before #7628#8079
lucaspimentel merged 12 commits intomasterfrom
lpimentel/APMSVLS-58-azfunc-host-parenting-pre-cleanup

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Execution-Time Benchmarks Report ⏱️

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Benchmarks

scenario:Benchmarks.Trace.ActivityBenchmark.StartStopWithChild netcoreapp3.1

scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody net6.0

scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.AllCycleSimpleBody netcoreapp3.1

scenario:Benchmarks.Trace.Asm.AppSecBodyBenchmark.ObjectExtractorSimpleBody net6.0

scenario:Benchmarks.Trace.Asm.AppSecEncoderBenchmark.EncodeLegacyArgs net6.0

scenario:Benchmarks.Trace.CIVisibilityProtocolWriterBenchmark.WriteAndFlushEnrichedTraces net472

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

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice net472

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSlice net6.0

scenario:Benchmarks.Trace.CharSliceBenchmark.OptimizedCharSliceWithPool net6.0

scenario:Benchmarks.Trace.GraphQLBenchmark.ExecuteAsync net472

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

scenario:Benchmarks.Trace.SingleSpanAspNetCoreBenchmark.SingleSpanAspNetCore netcoreapp3.1

scenario:Benchmarks.Trace.SpanBenchmark.StartFinishScope netcoreapp3.1

scenario:Benchmarks.Trace.SpanBenchmark.StartFinishSpan netcoreapp3.1

scenario:Benchmarks.Trace.SpanBenchmark.StartFinishTwoScopes net6.0

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