MCP JVM Diagnostics

JVM diagnostics MCP server for thread dump and GC log analysis. Detects deadlocks, lock contention, and GC pressure. Runs via npx on Node.js — no JVM or Docker required.

A Model Context Protocol (MCP) server that gives AI assistants the ability to analyze JVM thread dumps and GC logs. It detects deadlocks, identifies lock contention hotspots, analyzes garbage collection pressure, and recommends JVM tuning parameters.

JVM diagnostic MCP servers exist (TDA, jfr-mcp, Arthas) — but they're allJava-based, requiring a JVM runtime just to diagnose JVM problems. This tool runs onNode.jsvianpx— no JVM, no Docker, no SSH.

It analyzesofflineartifacts (thread dumps, GC logs, heap histograms) rather than requiring a running JVM. Paste a thread dump or GC log and get instant analysis.

- 6 MCP toolsfor comprehensive JVM diagnostics
- Thread dump analysis— deadlock detection, contention hotspots, thread state breakdown
- GC log analysis— pause statistics, heap trends, memory leak detection
- Heap histogram analysis— memory leak candidates, classloader leaks, finalization issues
- JFR summary— Java Flight Recorder file analysis
- Unified diagnosis— cross-correlates thread and GC data
- SupportsG1, ZGC, Parallel, Serial, and Shenandoah GC formats
- No external dependencies— works on local text input, no API keys needed

Generate exportable diagnostic reports (HTML + PDF)with a Pro license key.

- Full JVM thread dump analysis report with actionable recommendations
- PDF export for sharing with your team
- Priority support

Pro license key activates thegenerate_reportMCP tool in mcp-jvm-diagnostics.

Add to~/.claude/claude_desktop_config.json:

{ "mcpServers": { "jvm-diagnostics": { "command": "npx", "args": ["-y", "mcp-jvm-diagnostics"] } } }

No environment variables needed — this tool works on text input you provide.

Try these prompts in Claude (paste your JVM output):
- "Analyze this thread dump: [paste jstack output]"— Detects deadlocks, contention hotspots, and thread state breakdown
- "Analyze this GC log: [paste GC log]"— Shows pause statistics, heap trends, and tuning recommendations
- "Compare these heap histograms to find memory leaks: BEFORE: [paste] AFTER: [paste]"— Identifies growing classes, classloader leaks, and finalizer issues

Parse a JVM thread dump and analyze thread states, detect deadlocks, and identify lock contention.

- thread_dump— The full thread dump text (fromjstack <pid>,kill -3, or VisualVM)

Example prompt:"Analyze this thread dump and tell me if there are any deadlocks"

Parse a GC log and analyze garbage collection patterns, pause times, and memory pressure.

- gc_log— The GC log text (from-Xlog:gcor-verbose:gc)

# Using jstack jstack <pid> > thread-dump.txt # Using kill signal (Linux/Mac) kill -3 <pid> # Using jcmd jcmd <pid> Thread.print > thread-dump.txt

# Java 9+ (unified logging) -Xlog:gc:file=gc.log:time,level,tags # Java 8 -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Xloggc:gc.log

- Clone the repo
- npm install
- npm run build
- npm test

- Text input only: Thread dumps, GC logs, and heap histograms must be provided as text. The server cannot attach to a running JVM or capture data automatically.
- Java 9+ GC logs: The GC log parser is optimized for unified logging format (-Xlog:gc*). Legacy-verbose:gcformat (Java 8) has basic support but may miss some events.
- Shenandoah GC: Limited support. G1, ZGC, Parallel, and Serial are fully supported.
- Virtual threads (Java 21+): Thread dump parser handles virtual threads but analysis recommendations are tuned for platform threads.
- Heap histo comparison: Requires standardjmap -histoorjcmd GC.class_histogramformat. Custom formats or truncated output may not parse correctly.
- Deadlock detection: Detects monitor-based deadlocks. ReentrantLock deadlocks may not be detected if lock addresses are not visible in the thread dump.
- No historical analysis: Each analysis is a point-in-time snapshot. For trend analysis, compare multiple snapshots manually.
- HotSpot/OpenJDK only: Parser targets HotSpot/OpenJDK thread dump format. GraalVM native-image or Eclipse OpenJ9 dumps may parse incompletely.
- Classloader leak detection: Heap analysis flags growing ClassLoader instances but cannot definitively prove a leak without memory profiler data.

- mcp-db-analyzer— PostgreSQL/MySQL/SQLite schema analysis
- mcp-spring-boot-actuator— Spring Boot health, metrics, and bean analysis
- mcp-redis-diagnostics— Redis memory, slowlog, and client diagnostics
- mcp-migration-advisor— Flyway/Liquibase migration risk analysis

This MCP server is no longer maintained or distributed. The Corporation has pivoted to Apify marketplace actors. Seeirrationalwayson Apifyandirrcorp/bzp-poland-tendersfor current Corporation work.

A server for monitoring and analyzing Java Virtual Machine (JVM) processes using Arthas, with a Python interface.