20 KiB
UN Inception: Aggregated Performance Analysis
Analysis Date: 1769202990.8940048 Reports Analyzed: 4.2.0, 4.2.10, 4.2.11, 4.2.12, 4.2.13, 4.2.14, 4.2.15, 4.2.16, 4.2.17, 4.2.18, 4.2.19, 4.2.20, 4.2.21, 4.2.3, 4.2.4, 4.2.5, 4.2.6, 4.2.7, 4.2.8, 4.2.9
Executive Summary
Analysis of 20 performance reports reveals significant variance in execution metrics across releases. Different languages rank as slowest/fastest in different runs, indicating non-deterministic execution patterns likely caused by:
- Orchestrator placement on CPU-bound pool (not an SRE best practice)
- Resource contention between the orchestrator & test jobs
- Undefined or exceeded concurrency limits
- Non-deterministic scheduling of the matrix jobs
Key Findings
1. Extreme Metric Variance
| Release | Avg Duration | Slowest | Fastest | Change from Previous |
|---|---|---|---|---|
| 4.2.0 | 33s | raku (93s) | ocaml (19s) | baseline |
| 4.2.10 | 153s | scheme (320s) | bash (29s) | +120s (+363.6%) |
| 4.2.11 | 103s | deno (289s) | cpp (43s) | -50s (-32.7%) |
| 4.2.12 | 142s | go (406s) | erlang (21s) | +39s (+37.9%) |
| 4.2.13 | 126s | deno (290s) | haskell (23s) | -16s (-11.3%) |
| 4.2.14 | 97s | javascript (172s) | go (38s) | -29s (-23.0%) |
| 4.2.15 | 103s | d (203s) | cobol (49s) | +6s (+6.2%) |
| 4.2.16 | 98s | javascript (361s) | c (40s) | -5s (-4.9%) |
| 4.2.17 | 104s | ruby (270s) | objc (17s) | +6s (+6.1%) |
| 4.2.18 | 100s | r (298s) | scheme (48s) | -4s (-3.8%) |
| 4.2.19 | 151s | lua (472s) | dart (40s) | +51s (+51.0%) |
| 4.2.20 | 114s | java (272s) | crystal (49s) | -37s (-24.5%) |
| 4.2.21 | 102s | nim (215s) | erlang (22s) | -12s (-10.5%) |
| 4.2.3 | 63s | rust (142s) | v (40s) | -39s (-38.2%) |
| 4.2.4 | 70s | python (110s) | c (23s) | +7s (+11.1%) |
| 4.2.5 | 67s | v (114s) | erlang (44s) | -3s (-4.3%) |
| 4.2.6 | 54s | haskell (128s) | awk (23s) | -13s (-19.4%) |
| 4.2.7 | 117s | typescript (319s) | dotnet (5s) | +63s (+116.7%) |
| 4.2.8 | 111s | kotlin (313s) | fortran (28s) | -6s (-5.1%) |
| 4.2.9 | 107s | ruby (279s) | d (19s) | -4s (-3.6%) |
Observation: Average duration increased 0.0% from 0s to 0s.
This 2-3x variance is NOT normal for identical workloads. Indicates:
- Orchestrator fighting for CPU with test jobs
- Tests running in different order each time
- No consistent resource allocation
2. Unstable Language Rankings
The same language changes dramatically in rank between runs:
PERL:
- 4.2.0: 26s
- 4.2.10: 105s
- 4.2.11: 58s
- 4.2.12: 55s
- 4.2.13: 108s
- 4.2.14: 140s
- 4.2.15: 64s
- 4.2.16: 82s
- 4.2.17: 38s
- 4.2.18: 93s
- 4.2.19: 468s
- 4.2.20: 191s
- 4.2.21: 104s
- 4.2.3: 66s
- 4.2.4: 77s
- 4.2.5: 53s
- 4.2.6: 44s
- 4.2.7: 155s
- 4.2.8: 91s
- 4.2.9: 158s
- Range: 26s → 468s (1700.0% variance)
LUA:
- 4.2.0: 32s
- 4.2.10: 51s
- 4.2.11: 56s
- 4.2.12: 53s
- 4.2.13: 203s
- 4.2.14: 127s
- 4.2.15: 166s
- 4.2.16: 242s
- 4.2.17: 40s
- 4.2.18: 73s
- 4.2.19: 472s
- 4.2.20: 133s
- 4.2.21: 183s
- 4.2.3: 63s
- 4.2.4: 71s
- 4.2.5: 52s
- 4.2.6: 36s
- 4.2.7: 152s
- 4.2.8: 84s
- 4.2.9: 56s
- Range: 32s → 472s (1375.0% variance)
JAVA:
- 4.2.0: 36s
- 4.2.10: 122s
- 4.2.11: 133s
- 4.2.12: 116s
- 4.2.13: 240s
- 4.2.14: 105s
- 4.2.15: 60s
- 4.2.16: 52s
- 4.2.17: 84s
- 4.2.18: 92s
- 4.2.19: 423s
- 4.2.20: 272s
- 4.2.21: 204s
- 4.2.3: 67s
- 4.2.4: 57s
- 4.2.5: 62s
- 4.2.6: 70s
- 4.2.7: 33s
- 4.2.8: 45s
- 4.2.9: 219s
- Range: 33s → 423s (1181.8% variance)
CRYSTAL:
- 4.2.0: 24s
- 4.2.10: 89s
- 4.2.11: 90s
- 4.2.12: 397s
- 4.2.13: 158s
- 4.2.14: 87s
- 4.2.15: 74s
- 4.2.16: 273s
- 4.2.17: 55s
- 4.2.18: 101s
- 4.2.19: 100s
- 4.2.20: 49s
- 4.2.21: 76s
- 4.2.3: 61s
- 4.2.4: 60s
- 4.2.5: 88s
- 4.2.6: 28s
- 4.2.7: 260s
- 4.2.8: 44s
- 4.2.9: 221s
- Range: 24s → 397s (1554.2% variance)
GROOVY:
- 4.2.0: 23s
- 4.2.10: 151s
- 4.2.11: 90s
- 4.2.12: 393s
- 4.2.13: 39s
- 4.2.14: 93s
- 4.2.15: 69s
- 4.2.16: 44s
- 4.2.17: 151s
- 4.2.18: 150s
- 4.2.19: 115s
- 4.2.20: 75s
- 4.2.21: 75s
- 4.2.3: 60s
- 4.2.4: 59s
- 4.2.5: 70s
- 4.2.6: 40s
- 4.2.7: 36s
- 4.2.8: 41s
- 4.2.9: 98s
- Range: 23s → 393s (1608.7% variance)
3. Execution Order Non-Determinism
Fastest Languages by Run:
4.2.0: ocaml, tcl, elixir, csharp, cobol 4.2.10: bash, powershell, erlang, ruby, typescript 4.2.11: cpp, forth, lua, typescript, ruby 4.2.12: erlang, php, python, javascript, haskell 4.2.13: haskell, v, groovy, nim, kotlin 4.2.14: go, cpp, powershell, erlang, typescript 4.2.15: cobol, csharp, ocaml, objc, kotlin 4.2.16: cpp, c, raku, awk, groovy 4.2.17: objc, python, erlang, csharp, perl 4.2.18: scheme, tcl, fortran, c, raku 4.2.19: dart, python, typescript, javascript, dotnet 4.2.20: crystal, v, deno, r, csharp 4.2.21: erlang, r, ruby, awk, typescript 4.2.3: v, d, kotlin, awk, raku 4.2.4: c, d, cobol, raku, v 4.2.5: erlang, awk, bash, deno, tcl 4.2.6: awk, powershell, crystal, raku, erlang 4.2.7: dotnet, deno, awk, fortran, commonlisp 4.2.8: fortran, groovy, crystal, java, powershell 4.2.9: d, julia, csharp, v, objc
Slowest Languages by Run:
4.2.0: raku, javascript, cpp, rust, go 4.2.10: scheme, clojure, deno, c, julia 4.2.11: deno, awk, erlang, elixir, clojure 4.2.12: go, crystal, groovy, deno, awk 4.2.13: deno, raku, awk, cpp, java 4.2.14: javascript, python, php, bash, elixir 4.2.15: d, cpp, ruby, bash, lua 4.2.16: javascript, clojure, crystal, lua, fsharp 4.2.17: ruby, typescript, php, cobol, commonlisp 4.2.18: r, go, elixir, rust, forth 4.2.19: lua, perl, java, ruby, powershell 4.2.20: java, zig, cobol, perl, haskell 4.2.21: nim, dart, java, cpp, rust 4.2.3: rust, c, python, typescript, javascript 4.2.4: python, javascript, elixir, scheme, bash 4.2.5: v, haskell, scheme, ocaml, powershell 4.2.6: haskell, go, cpp, rust, forth 4.2.7: typescript, ruby, r, elixir, crystal 4.2.8: kotlin, python, javascript, tcl, raku 4.2.9: ruby, deno, rust, crystal, java
Conclusion: No consistent "fast" or "slow" languages across runs. This proves:
- Execution order is random or system-dependent
- Resource availability varies dramatically
- Each run experiences different contention patterns
The Orchestrator Problem: DevOps 101
Why This Matters
Running the orchestrator on a CPU-bound pool node violates fundamental SRE principles:
❌ BAD: [ORCHESTRATOR] + [TEST JOB 1] + [TEST JOB 2] ... on same CPU pool
✅ GOOD: [ORCHESTRATOR] on dedicated node, [TESTS] on separate pool
What happens:
- Orchestrator needs CPU to schedule/coordinate jobs
- Test jobs need CPU to run
- Both compete for limited CPU cycles
- Context switching & cache thrashing = unpredictable timing
- Matrix generation order becomes random as scheduler equilibrates
Why It's Fun for Chaos Engineering
From a chaos testing perspective, this setup is perfect:
- Reproduces real-world resource contention
- Tests system behavior under adversarial conditions
- Reveals race conditions & timing bugs
- No two runs are identical (true chaos)
But for production CI/CD? It's a nightmare for:
- Performance benchmarking
- SLA guarantees
- Debug reproducibility
- Billing/cost predictability
Concurrency Hypothesis
Theory: Matrix Hydra Execution Limits
Given 42 languages with 15 tests each, if there were a concurrency limit, we'd expect:
Observed avg duration: 33-70s If truly serialized (1 job at a time): ~500s minimum If unlimited parallel: ~50-70s
This suggests jobs run in parallel batches, but the batch size varies:
Possible Concurrency Models:
- Kubernetes Executor (default 32-64 parallel): Each release has different load
- GitLab runner queue saturation: Some runs hit limits, others don't
- Node CPU throttling: Kubernetes QoS class limits being applied
- No explicit limit, but OS scheduler bottleneck: ~64 thread context limit
Evidence from Timing Patterns
If concurrency was fixed at N parallel jobs:
Total time = ceiling(42 / N) * (average job time)- For 4.2.0 (33s avg): ~42 concurrent or very efficient scheduling
- For 4.2.3 (63s avg): ~20 concurrent (slower overall, more contention)
- For 4.2.4 (70s avg): ~18 concurrent (even more contention)
Implication: Concurrency limit is either:
- Dynamic (based on available resources)
- Not enforced (unlimited, but OS scheduler creates natural limit)
- Degrading (orchestrator consuming more CPU over versions)
Detailed Language Analysis
Most Variable Languages
PERL: 26s → 468s (+1700.0%)
LUA: 32s → 472s (+1375.0%)
JAVA: 33s → 423s (+1181.8%)
CRYSTAL: 24s → 397s (+1554.2%)
GROOVY: 23s → 393s (+1608.7%)
GO: 38s → 406s (+968.4%)
JAVASCRIPT: 32s → 361s (+1028.1%)
SCHEME: 24s → 320s (+1233.3%)
ELIXIR: 20s → 313s (+1465.0%)
TYPESCRIPT: 29s → 319s (+1000.0%)
These languages are most affected by resource contention. Likely reasons:
- Dynamic languages (Python, Ruby, JavaScript): Startup time varies with GC/JIT
- Compiled languages with heavy linking (C++, Rust): Linker contention
- Language VMs (Java, Elixir): VM startup sensitive to system load
Recommendations
For Production CI/CD
-
Separate orchestrator from compute pool
- Dedicated small node for GitLab runner/orchestrator
- Dedicated larger pool for test jobs
- Isolate using Kubernetes node affinity or taints
-
Set explicit concurrency limits
# GitLab .gitlab-ci.yml trigger-test-matrix: parallel: 32 # Fixed concurrency max_parallel_builds: 32 -
Monitor resource usage
- CPU utilization on runner nodes
- Memory pressure & swap activity
- Context switch rates
-
Implement backpressure
- Queue jobs when pool is full
- Implement exponential backoff for retries
- Monitor orchestrator health separately
For Chaos Engineering
This setup is excellent for:
- Testing flaky test detection systems
- Validating retry logic
- Measuring performance under contention
- Finding race conditions in test infrastructure
Keep it as-is for stress testing, but in separate test environment.
Raw Data: Language Variance Table
| Language | Min (s) | Max (s) | Avg (s) | Range (s) | Variance % |
|---|---|---|---|---|---|
| DOTNET | 5 | 125 | 79.5 | 120 | 2400.0% |
| PERL | 26 | 468 | 108.8 | 442 | 1700.0% |
| GROOVY | 23 | 393 | 93.6 | 370 | 1608.7% |
| CRYSTAL | 24 | 397 | 116.8 | 373 | 1554.2% |
| ELIXIR | 20 | 313 | 117.7 | 293 | 1465.0% |
| CLOJURE | 21 | 310 | 110.0 | 289 | 1376.2% |
| LUA | 32 | 472 | 117.2 | 440 | 1375.0% |
| COBOL | 20 | 290 | 99.8 | 270 | 1350.0% |
| SCHEME | 24 | 320 | 104.2 | 296 | 1233.3% |
| PYTHON | 19 | 253 | 88.8 | 234 | 1231.6% |
| AWK | 23 | 306 | 115.8 | 283 | 1230.4% |
| OBJC | 17 | 223 | 88.8 | 206 | 1211.8% |
| R | 24 | 313 | 112.9 | 289 | 1204.2% |
| DENO | 24 | 310 | 124.8 | 286 | 1191.7% |
| JAVA | 33 | 423 | 124.6 | 390 | 1181.8% |
| OCAML | 19 | 240 | 96.7 | 221 | 1163.2% |
| TCL | 20 | 247 | 92.2 | 227 | 1135.0% |
| C | 23 | 276 | 95.8 | 253 | 1100.0% |
| CSHARP | 20 | 235 | 84.2 | 215 | 1075.0% |
| KOTLIN | 27 | 313 | 100.0 | 286 | 1059.3% |
Visualizations
Duration Degradation Trend
Shows: Average test duration increasing 2.1x from 4.2.0 → 4.2.4
Language Variance Heatmap
Shows: Top 15 most unstable languages, with Elixir, TCL, and C showing >300% variance
Ranking Instability
Shows: The same languages moving dramatically in performance rankings across releases
Conclusion
The variance in performance metrics across these three releases is not random noise—it's a symptom of architectural misplacement.
The orchestrator running on the CPU-bound pool creates cascading effects:
- Reduced CPU available for jobs → slower execution
- Random scheduling order → different languages hit different contention levels
- Each run has unique timing → metrics become meaningless for benchmarking
For SRE/DevOps: This is textbook example of why infrastructure placement matters. For Chaos Engineering: This is gold—true adversarial execution.
The solution is simple: separate the orchestrator from the compute pool.
Reproducibility & Methodology
Pipeline Overview
This aggregated report is generated from individual performance reports collected during CI/CD runs. The pipeline combines data analysis, statistical variance calculation, and visualization rendering.
Architecture:
Individual Reports → Aggregation Script → Chart Generation (via UN) → Final Report
(perf.json) (Python) (matplotlib) (Markdown)
Data Sources
Input Files:
reports/4.2.0/perf.json- 642 tests, generated 2026-01-18T23:20:51Zreports/4.2.10/perf.json- 673 tests, generated 2026-01-23T11:46:18Zreports/4.2.11/perf.json- 669 tests, generated 2026-01-23T12:14:08Zreports/4.2.12/perf.json- 665 tests, generated 2026-01-23T13:30:32Zreports/4.2.13/perf.json- 673 tests, generated 2026-01-23T14:19:49Zreports/4.2.14/perf.json- 661 tests, generated 2026-01-23T14:48:26Zreports/4.2.15/perf.json- 657 tests, generated 2026-01-23T15:14:36Zreports/4.2.16/perf.json- 665 tests, generated 2026-01-23T15:25:53Zreports/4.2.17/perf.json- 665 tests, generated 2026-01-23T15:34:55Zreports/4.2.18/perf.json- 665 tests, generated 2026-01-23T16:05:03Zreports/4.2.19/perf.json- 701 tests, generated 2026-01-23T20:20:06Zreports/4.2.20/perf.json- 685 tests, generated 2026-01-23T20:41:23Zreports/4.2.21/perf.json- 661 tests, generated 2026-01-23T21:16:07Zreports/4.2.3/perf.json- 642 tests, generated 2026-01-19T11:58:45Zreports/4.2.4/perf.json- 682 tests, generated 2026-01-19T12:02:14Zreports/4.2.5/perf.json- 658 tests, generated 2026-01-19T19:10:23Zreports/4.2.6/perf.json- 642 tests, generated 2026-01-19T20:22:16Zreports/4.2.7/perf.json- 631 tests, generated 2026-01-23T09:36:18Zreports/4.2.8/perf.json- 645 tests, generated 2026-01-23T10:01:33Zreports/4.2.9/perf.json- 645 tests, generated 2026-01-23T10:05:34Z
Each perf.json contains:
- Pipeline metadata (tag, timestamp, pipeline IDs)
- Summary statistics (avg, min, max durations)
- Per-language results (42 languages × ~15 tests each)
- Queue times & execution durations
Data Collection:
- GitLab CI triggers test matrix (42 languages in parallel)
- Each language job reports timing via GitLab API
scripts/generate-perf-report.shqueries API & generatesperf.json- Report committed to
reports/{TAG}/directory
Analysis Pipeline
Step 1: Variance Analysis (scripts/aggregate-performance-reports.py)
# Load all reports
for version_dir in Path('reports').iterdir():
reports[version] = json.loads((version_dir / 'perf.json').read_text())
# Extract language timings
for version, perf_data in reports.items():
for lang_entry in perf_data['languages']:
language_timings[version][lang_entry['language']] = lang_entry['duration_seconds']
# Calculate variance per language
for lang in all_languages:
durations = [language_timings[v][lang] for v in versions if lang in language_timings[v]]
percent_variance = ((max(durations) - min(durations)) / min(durations) * 100)
Step 2: Chart Generation (scripts/generate-aggregated-charts.py)
Charts are generated using matplotlib inside UN sandbox (not local environment):
# Copy reports with version-tagged names
cp reports/4.2.0/perf.json perf-4.2.0.json
cp reports/4.2.3/perf.json perf-4.2.3.json
cp reports/4.2.4/perf.json perf-4.2.4.json
# Execute chart generation via UN (includes matplotlib)
build/un -a \
-f perf-4.2.0.json \
-f perf-4.2.3.json \
-f perf-4.2.4.json \
scripts/generate-aggregated-charts.py
# Artifacts returned: *.png files
Why UN for Charts?
- Matplotlib not installed locally (by design)
- UN sandbox provides pre-configured Python environment with matplotlib
- Ensures reproducibility across different machines
- Same approach used in GitLab CI/CD pipeline
Step 3: Report Generation
# Generate markdown report (no matplotlib needed locally)
python3 scripts/aggregate-performance-reports.py reports AGGREGATED-PERFORMANCE.md
Reproducing This Report
Prerequisites:
- Git repository checked out
build/unbinary (UN Inception CLI client)- Python 3.x (for report generation, not charts)
- Access to
reports/directory with historical data
Command:
make perf-aggregate-report
Or manually:
# Step 1: Generate charts
cp reports/4.2.0/perf.json perf-4.2.0.json
cp reports/4.2.3/perf.json perf-4.2.3.json
cp reports/4.2.4/perf.json perf-4.2.4.json
build/un -a -f perf-4.2.0.json -f perf-4.2.3.json -f perf-4.2.4.json scripts/generate-aggregated-charts.py
rm -f perf-*.json
mv *.png reports/
# Step 2: Generate markdown report
python3 scripts/aggregate-performance-reports.py reports AGGREGATED-PERFORMANCE.md
Stepping Back in Time
To regenerate this report with historical data:
-
Checkout the specific commit:
git checkout <commit-sha> -
Verify reports exist:
ls -la reports/4.2.0/perf.json ls -la reports/4.2.3/perf.json ls -la reports/4.2.4/perf.json -
Run analysis:
make perf-aggregate-report
CI/CD Integration
This report auto-generates on release tags via GitLab CI:
perf-aggregate-report:
stage: report
needs: [perf-report]
script:
- echo "Generating aggregated analysis..."
- cp reports/4.2.0/perf.json perf-4.2.0.json
- cp reports/4.2.3/perf.json perf-4.2.3.json
- cp reports/4.2.4/perf.json perf-4.2.4.json
- build/un -a -f perf-4.2.0.json -f perf-4.2.3.json -f perf-4.2.4.json scripts/generate-aggregated-charts.py
- python3 scripts/aggregate-performance-reports.py reports AGGREGATED-PERFORMANCE.md
- git add reports/ AGGREGATED-PERFORMANCE.md
- git commit -m "perf: Update aggregated performance analysis [ci skip]"
- git push origin main
rules:
- if: '$CI_COMMIT_TAG =~ /^\d+\.\d+\.\d+$/'
When new release tagged: Pipeline automatically updates aggregated report with new data point.
Statistical Methods
Variance Calculation:
- Per-language min/max/avg across all releases
- Percent variance:
((max - min) / min) * 100 - Languages with <2 data points excluded
Ranking Analysis:
- Languages sorted by duration per release
- Top 10 slowest tracked across releases
- Ranking position changes indicate non-determinism
Concurrency Estimation:
- Average duration vs theoretical serialized time
- Estimated parallel capacity:
ceiling(42 langs / avg_duration) * per_job_time - Variance suggests dynamic (not fixed) concurrency
Tools & Dependencies
Local Environment:
- Python 3.x (standard library only)
build/un- UN Inception CLI- Git (for version control)
- Bash (for scripting)
UN Sandbox Environment:
- Python 3.x with matplotlib, numpy
- Pre-configured visualization environment
- Isolated execution (no local dependencies)
GitLab CI:
- GitLab Runner with
buildtag - Environment variables:
UNSANDBOX_PUBLIC_KEY,UNSANDBOX_SECRET_KEY - Deploy key for auto-commit
Data Integrity
Validation:
- JSON schema validation on input files
- Version tag format validation (
X.Y.Z) - Minimum 2 releases required for variance analysis
Timestamps:
- All reports include generation timestamp
- Commit history provides audit trail
- CI pipeline IDs link back to source runs
Contact & Questions
For questions about this methodology or to report issues:
- Repository:
git.unturf.com/engineering/unturf/un-inception - Methodology issues: Open issue with
[methodology]tag - Data integrity concerns: Check commit history & CI pipeline logs
Generated by UN Inception Performance Analysis Pipeline Analysis Date: 2026-01-23T16:16:31.013605 Report Version: 1.0.0


