Changelog

analyze <file.jfr|dir> — summarize a recording, or a directory of them (a JMH -prof jfr run: every fork’s .jfr merged into one summary), into markdown / JSON / prompt; --baseline <before.jfr> diffs two recordings — anchored on absolute weight (bytes / ms / samples) with share as context, so an optimize-loop reduction isn’t mislabelled a regression; --assert "<rules>" is a CI perf-gate (non-zero exit on regression); --hints adds hedged [possible] fix directions; --top-k <n> / --max-tokens <n> budget the size; --skip-warmup <ms> drops JIT/classload churn (per-file cutoff) for steady-state hot paths.

profile <pid> — live attach + timed JFR capture (no pre-recorded file); --engine async adds native frames via async-profiler; -w/--warmup, -k/--keep.

bench --main <class> — the no-JMH harness: runs any main(String[]) in a warmup→timed loop, captures a JFR over only the timed phase, and summarizes; --cp, -w/--warmup, -i/--iters, --jfr (keep for a baseline diff).

watch <pid> — continuous ring buffer; periodic, or dump-on-trigger (--on-gc-ms / --on-cpu-pct / --on-old-objects).

trend <history.jsonl> — reduce a long-running monitor’s accumulated history to a change-over-time digest (per-dimension direction, hot-path shift, hedged retention).

control <control-file> <cmd…> — in-flight agent control (see Runtime control).

mcp — stdio MCP server exposing scoped, navigable tools (one per dimension) plus a live profile tool; reachable remotely over stdio-over-ssh. Serves data only — never calls an LLM.

JMH profiler plugin — -prof org.alexmond.jvmlens.jmh.JvmlensProfiler prints the summary inline after a benchmark trial; keep=<path> retains the fork’s recording and baseline=<prev.jfr> prints the diff inline (the whole optimize loop inside one JMH run). Ships as a dependency-light jvmlens-jmh.jar (engine + profiler, no Spring/picocli/jmh).

CPU — hot paths (application-attributed) + hot leaf methods.

Memory — allocation sites + types, GC pressure.

Wait — lock contention by method + contended monitors.

External I/O — socket + file blocking I/O by endpoint (jdk.SocketRead/Write, jdk.FileRead/Write).

Virtual-thread pinning — jdk.VirtualThreadPinned by site, with pinnedReason.

Deadlocks — authoritative ThreadMXBean.findDeadlockedThreads wait-for cycle (agent).

Database (SQL) — agent JDBC instrumentation; sanitized SQL shapes, latency, N+1 flag.

HTTP endpoints — agent servlet instrumentation; route-shape, latency, errors.

Messaging / cache — agent Kafka/JMS and Spring-Cache operation timing.

Micrometer — summarize an existing registry’s timers (no extra instrumentation).

Variable snapshots — agent snapshot=Class#method argument digests (correctness).

Cross-dimension correlation — a hedged note co-locating the dominant signal per dimension.

Per-row absolute hit count beside every share; sections tagged [sampled] vs [measured]; a ⚠ adequacy caveat under 200 execution samples, and a matching per-site allocation caveat when there are too few allocation samples (the total stays reliable).

Source-line anchoring — hot-path leaves and allocation sites carry their source line (Svc.compute:88), so a coding agent goes from diagnosis to the edit in one step.

Leaf confidence — a hot path’s teaser lists the top leaves with counts and flags ⚠ diffuse when no single leaf dominates, instead of trusting one (possibly stray) frame.

The heuristic under-interprets — retention is flagged as possible growth, never a confident "leak"; correlation suggests, never asserts.

-javaagent:jvmlens-agent.jar — in-process, container-native, no attach/JMX. Writes periodic summaries; history= appends a JSONL time-series; per-dimension opt-in.

Runtime control via a watched control file (control=<file>) + the jvmlens control CLI: start/stop, clear, dump, enable/disable <dim>, settings profile|default, interval, scope app|exclude|reset (filtering), topn [<category>] <n> (rows/section), status — each returns the agent’s state to the caller. No ports, no JMX.

paused launch + start-after-warm-up — the clean fix for short cold runs profiling startup.

Formats md / json / prompt; report focuses full / cpu / memory / locks / gc / io / pinning / db / web / messaging / cache / metrics / deadlock.

Application-frame scoping (-a/--app-package, -x/--exclude); runtime-adjustable top-N.

Dependency-free engine (jdk.jfr.consumer only) reused by every front-end.

Standalone Helm chart (deploy/helm/jvmlens) + scripts/deploy-agent.sh attach the agent to any JVM image as a separate release, without touching the app’s own chart.