Utility to debug memory usage of NodeJS processes.

Based on heapdump.

Usage

Requiring the module will activate it. It has no functions.

require("heapdumper");

Now, your process will dump a .heapsnapshot file to its current directory if you send it the USR2 signal.

Example use, where the program myserverthing.js uses heapdumper:

$ node myserverthing.js &
[1] 4955
$ kill -s USR2 4955
USR2 received - creating .heapdump file in /home/helge/proj/heapdumper
$ ls
heapdump-3808509.864648.heapsnapshot
heapdump-3808509.864648.log
myserverthing.js
node_modules 
$

Install

The module is available via NPM.

npm install heapdumper

Inspecting the .heapsnapshot files

Chrome/Chromium has a profiling tool to visually inspect the heap: Chrome heap profiling

Quick recipe: Open Chrome, open dev tools, go to "profiles tab", right click in the tool area and select "Load profile". Navigate to the generated .heapsnapshot file and open it. Enjoy.