jvm mon

jvm-mon

Console based JVM monitoring - when you just want to SSH into a server and see what's going on.

jvm-top lets you monitor your JVM server applications from the terminal.

New Version

Release: 1.0-ea1

• Rewritten in Go
• Single executable file
• Can monitor applications on Java 8 and above
• Does not require an existing JDK

How it works:

• jvm-mon executable comes bundled with a Java agent jar
• On startup it extracts the agent to a temp directory
• It attaches to the JVM you want to monitor
• Loads agent into running JVM to collect metrics
• Agent and app establish a socket connection to send metrics

Install

Requirement: a JDK8 on the server and JAVA_HOME environment variable pointing to it. It won't work with just a JRE.

MacOS

brew install jvm-mon

Linux/MacOS

1. Download the release and extract
2. Set JAVA_HOME environment variable: export JAVA_HOME=/path/to/your/jdk8
3. Execute ./bin/jvm-mon from extracted directory

Usage

• Select a JVM process and press Enter to monitor it
• Press q or Ctrl+C to exit
• Press Del or Backspace to kill a process

What is available

Currently it shows:

• List of running JVM processes
• Cpu and GC load
• Heap size and usage
• Top threads with cpu usage

Building from source

To build locally run ./gradlew installDist. Then go to ./build/install/jvm-mon/ and run ./bin/jvm-mon.

To develop you will need npm on your machine and then run ./gradlew npmDeps once to get dependencies.

How does it work?

jvm-mon is a Kotlin application based on these awesome libraries:

• blessed-contrib terminal dashboard library in JavaScript
• J2V8 Java Bindings for V8 JavaScript engine and Node.js
• jvmtop Java monitoring for the command-line

The way it works is:

1. The Kotlin app starts a Node.js engine in-process
2. Node.js loads a script with all the widgets
3. The script calls back into Kotlin to get metrics