Flight Dump Viewer

A JetBrains IDE plugin that opens and visualizes Java Flight Recorder (.jfr) recordings directly inside the editor — no need to fire up JDK Mission Control.

Features

• CPU flame graph — width-proportional, theme-aware, with mouse-wheel zoom around the cursor, drag-to-pan, click-to-focus subtree, and a back/reset toolbar
• Hot Spots table — sortable methods with self/total CPU %, plus a callers/callees drill-down split
• GC & memory timeline — heap-used area + GC-pause bars over the recording's wall-clock span
• Generic event browser — pick any JFR event type, inspect raw fields and stack traces
• Open existing recordings — Tools → Open JFR Recording…
• Attach to a running JVM — Tools → JFR Recording → Start Recording on Local JVM… (uses com.sun.tools.attach + HotSpot's JFR.start diagnostic command)
• Record from a run configuration — injects -XX:StartFlightRecording=… and auto-opens the produced file
• Settings under Preferences → Tools → JFR Viewer (default duration, settings profile, output dir, auto-open)

Parsing is done with the JDK's built-in jdk.jfr.consumer.RecordingFile — no extra runtime dependencies.

Install

Grab the latest stable build:

• Latest release — v1.0.0
• Nightly (auto-built from main) — flightdumpviewer-nightly.zip

In the IDE: Settings → Plugins → ⚙ → Install Plugin from Disk… and pick the zip.

⚠️ Don't download from the Actions tab — actions/upload-artifact@v4 re-wraps uploads in an extra zip, so the file you'd get is a zip containing the plugin zip. The Release URLs above serve the real plugin zip.

Compatibility

	Version
Target IDE	IntelliJ IDEA Community / Ultimate 2025.2+ (build 252)
Build runtime	JDK 21
Language	Kotlin 2.2
Build	IntelliJ Platform Gradle Plugin v2.6

The plugin requires the bundled Java module, so it loads in IDEA but not in non-Java JetBrains IDEs (PyCharm, GoLand, etc.).

Build

JAVA_HOME=$(/usr/libexec/java_home -v 21) ./gradlew buildPlugin

The plugin zip lands at build/distributions/flightdumpviewer-<version>.zip.

JAVA_HOME=$(/usr/libexec/java_home -v 21) ./gradlew runIde     # sandbox IDE
JAVA_HOME=$(/usr/libexec/java_home -v 21) ./gradlew test       # run tests
JAVA_HOME=$(/usr/libexec/java_home -v 21) ./gradlew verifyPlugin

JDK 21 is required — the IntelliJ Platform 2025.x doesn't run on 17, and Gradle 8.10 doesn't support JDK 25+.

For deeper architecture and contributor notes, see CLAUDE.md.

Releasing

A v* tag triggers .github/workflows/release.yml:

1. Builds the plugin with the tag's version (-PpluginVersion=…).
2. Creates a GitHub Release with auto-generated notes and the zip attached.

git tag v1.1.0
git push origin v1.1.0

Nightly builds

Every push to main produces a nightly via .github/workflows/build.yml, published to a moving nightly pre-release at the URL listed in Install.

Project layout

src/main/kotlin/ltd/chrshnv/flightdumpviewer/
├─ jfr/        # JfrLoader + extractors (CPU, allocations, GC, event type index)
├─ model/      # In-memory analyses: StackTreeNode, HotSpot, GcTimelinePoint, EventRow
├─ ui/         # FileEditor, 4 view panels (flamegraph / hotspots / gc / events), tool window
├─ actions/    # Open .jfr, Start / Stop recording on local JVM
├─ recording/  # JvmAttachService, JfrRunConfigurationExtension
└─ settings/   # Persistent state + Configurable

Roadmap

• per-run-config UI tab to toggle "record JFR on run" (currently opt-in via XML attribute)
• thread filter and time-range filter on Hot Spots
• flame graph ↔ hot-spots cross-selection
• checked-in sample .jfr for integration tests

License

Apache License 2.0 — see LICENSE.