NodeJS Profiling

Best NodeJS Versions for profiling

If possible, do yourself a favor and test your code to make sure it works with NodeJS version 6.3 or greater.

• Official support for Node.js debuggability landed in Node.js version 6.3 in May 2016.

• Before v6.3: https://github.com/node-inspector/node-inspector

Profiling

Memory

1. expose port 9229 if using docker

2. and start your code: node --inspect --debug-brk myCode.js

   1. it will output a url to connect with chrome://inspect/#devices, go ahead and copy/paste that URL into chrome

3. under the sourcestab, place breakpoints where ever you want ... then hit play to let the code run

   • Your code starts in "paused" mode because of --debug-brk

4. take a snapshot, then:

   1. either, run requests against web server to cause load

   2. or, simply let your one-time nodejs code run until it hits a breakpoint

5. take another snapshot

6. compare heap snapshots in chrome devtools