How do I install the Docker Jfr Benchmark Loop skill?

Run npx skillmds@latest add tomevault-io/docker-jfr-benchmark-loop in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Docker Jfr Benchmark Loop safe to use?

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Which AI agents work with Docker Jfr Benchmark Loop?

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Is Docker Jfr Benchmark Loop free to use?

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Who published Docker Jfr Benchmark Loop?

tomevault-io (@tomevault-io) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Docker Jfr Benchmark Loop by tomevault-io

Name: Docker Jfr Benchmark Loop
Author: tomevault-io

Docker Jfr Benchmark Loop

Run a repeatable RDF4J performance loop against one JMH benchmark in Docker with Linux Java 26 and JFR CPU-time profiling. Use when working in this repo on benchmark-guided performance changes, hotspot triage, JFR reading, CPU bottleneck analysis, or repeated baseline, fix, and rerun loops. Trigger on requests mentioning benchmark, profiling, JFR, hotspot, perf loop, CPU bottleneck, or Docker benchmark runs in RDF4J. Use when this capability is needed.

tomevault-io Updated Sep 17, 2026

File contents

Docker JFR Benchmark Loop

Use this skill for one-benchmark perf work in this repo. Default runner: scripts/run-docker-jfr-loop.sh, not ad hoc Maven or raw JMH commands.

Quick start

Dry-run a known selector:

.codex/skills/docker-jfr-benchmark-loop/scripts/run-docker-jfr-loop.sh \
  org.eclipse.rdf4j.model.benchmark.ValueCreationBenchmark.createBNode \
  --dry-run

Explicit selector plus params:

.codex/skills/docker-jfr-benchmark-loop/scripts/run-docker-jfr-loop.sh \
  --module core/model \
  --class org.eclipse.rdf4j.model.benchmark.ValueCreationBenchmark \
  --method createBNode \
  --param samples=1000

Repo-grounded defaults

The wrapper calls repo helper scripts/run-single-benchmark-docker.sh.
The Docker helper already forces Linux Java 26 plus --enable-jfr --enable-jfr-cpu-times.
The inner helper already enforces:
- settings=profile
- dumponexit=true
- duration=120s
- warmup=0
- measurement=10 iterations of 10s
- forks=1
- jdk.CPUTimeSample#enabled=true
- report-on-exit=cpu-time-hot-methods
This skill wrapper adds the missing fidelity flags:
- -XX:FlightRecorderOptions=stackdepth=1024,samplethreads=true
- -XX:+UnlockDiagnosticVMOptions
- -XX:+DebugNonSafepoints

Core loop

Pick one benchmark selector. Keep selector, params, Docker image, and profiling flags constant for the whole comparison.
Capture a baseline run with scripts/run-docker-jfr-loop.sh.
Read the .jfr using references/jfr-reading.md.
Choose one candidate fix with material CPU share. Prefer the fix most likely to move total runtime, not just local self time.
Re-run the exact same selector and params.
Compare benchmark delta plus hotspot shift.
Repeat until:
- the hotspot shifts,
- CPU share falls below a meaningful threshold,
- or GC / locks / memory / I/O / JIT behavior dominates instead.

Operating rules

Route benchmark variation through --param.
Route JVM tuning through --jvm-arg.
Do not use raw --jmh-arg during JFR runs; the helper rejects extra JMH args when JFR is enabled.
Do not switch to a second StartFlightRecording; stay aligned with repo helper behavior.
Do not treat a small benchmark gain as proof the hotspot fix failed. First check whether another bottleneck surfaced and now caps the total speedup.
If the run is not CPU-bound, say so and pivot to lock, GC, memory, I/O, or JIT evidence instead of forcing a CPU-only story.

Output contract

Answers using this skill should usually include:

exact run command
.jfr path
top CPU hotspots
confidence notes
next-fix hypothesis
whether a second bottleneck likely masks part of the gain

Escalate cleanly

Use high-performance-java for algorithm, data-structure, and code-shape changes.
Use hotspot-jit-forensics when inlining, tiering, C2, or codegen behavior is in question.
Use jmh-benchmark-compare for multi-run diffs, history, and exported reports.

Reference map

Loop workflow: references/perf-loop.md
JFR reading guide: references/jfr-reading.md

Source: eclipse-rdf4j/rdf4j — distributed by TomeVault.

---name: docker-jfr-benchmark-loopdescription: Run a repeatable RDF4J performance loop against one JMH benchmark in Docker with Linux Java 26 and JFR CPU-time profiling. Use when working in this repo on benchmark-guided performance changes, hotspot triage, JFR reading, CPU bottleneck analysis, or repeated baseline, fix, and rerun loops. Trigger on requests mentioning benchmark, profiling, JFR, hotspot, perf loop, CPU bottleneck, or Docker benchmark runs in RDF4J. Use when this capability is needed.---# Docker JFR Benchmark LoopUse this skill for one-benchmark perf work in this repo. Default runner: `scripts/run-docker-jfr-loop.sh`, not ad hoc Maven or raw JMH commands.## Quick startDry-run a known selector:```bash.codex/skills/docker-jfr-benchmark-loop/scripts/run-docker-jfr-loop.sh \ org.eclipse.rdf4j.model.benchmark.ValueCreationBenchmark.createBNode \ --dry-run```Explicit selector plus params:```bash.codex/skills/docker-jfr-benchmark-loop/scripts/run-docker-jfr-loop.sh \ --module core/model \ --class org.eclipse.rdf4j.model.benchmark.ValueCreationBenchmark \ --method createBNode \ --param samples=1000```## Repo-grounded defaults- The wrapper calls repo helper `scripts/run-single-benchmark-docker.sh`.- The Docker helper already forces Linux Java 26 plus `--enable-jfr --enable-jfr-cpu-times`.- The inner helper already enforces: - `settings=profile` - `dumponexit=true` - `duration=120s` - `warmup=0` - `measurement=10` iterations of `10s` - `forks=1` - `jdk.CPUTimeSample#enabled=true` - `report-on-exit=cpu-time-hot-methods`- This skill wrapper adds the missing fidelity flags: - `-XX:FlightRecorderOptions=stackdepth=1024,samplethreads=true` - `-XX:+UnlockDiagnosticVMOptions` - `-XX:+DebugNonSafepoints`## Core loop1. Pick one benchmark selector. Keep selector, params, Docker image, and profiling flags constant for the whole comparison.2. Capture a baseline run with `scripts/run-docker-jfr-loop.sh`.3. Read the `.jfr` using [references/jfr-reading.md](references/jfr-reading.md).4. Choose one candidate fix with material CPU share. Prefer the fix most likely to move total runtime, not just local self time.5. Re-run the exact same selector and params.6. Compare benchmark delta plus hotspot shift.7. Repeat until: - the hotspot shifts, - CPU share falls below a meaningful threshold, - or GC / locks / memory / I/O / JIT behavior dominates instead.## Operating rules- Route benchmark variation through `--param`.- Route JVM tuning through `--jvm-arg`.- Do not use raw `--jmh-arg` during JFR runs; the helper rejects extra JMH args when JFR is enabled.- Do not switch to a second `StartFlightRecording`; stay aligned with repo helper behavior.- Do not treat a small benchmark gain as proof the hotspot fix failed. First check whether another bottleneck surfaced and now caps the total speedup.- If the run is not CPU-bound, say so and pivot to lock, GC, memory, I/O, or JIT evidence instead of forcing a CPU-only story.## Output contractAnswers using this skill should usually include:- exact run command- `.jfr` path- top CPU hotspots- confidence notes- next-fix hypothesis- whether a second bottleneck likely masks part of the gain## Escalate cleanly- Use [high-performance-java](../high-performance-java/SKILL.md) for algorithm, data-structure, and code-shape changes.- Use [hotspot-jit-forensics](../hotspot-jit-forensics/SKILL.md) when inlining, tiering, C2, or codegen behavior is in question.- Use [jmh-benchmark-compare](../jmh-benchmark-compare/SKILL.md) for multi-run diffs, history, and exported reports.## Reference map- Loop workflow: [references/perf-loop.md](references/perf-loop.md)- JFR reading guide: [references/jfr-reading.md](references/jfr-reading.md)---> Source: [eclipse-rdf4j/rdf4j](https://github.com/eclipse-rdf4j/rdf4j) — distributed by [TomeVault](https://tomevault.io).

Frequently asked questions