doc: add diagnosis memory leak guide

[tony-go]

Hi Node Familly 👋

Context

The Diagnostic Working Group started an initiative to re-assess the diagnostics tools list.

I start to work around the --trace-gc flag:

• add it to the list itself chore(doc): add trace_gc to diagnostic tooling support document node#42346
• add tests test: add --trace-gc flag test node#42471

But something is missing... 😞

If you take a look at the diagnostic tooling support tiers, you'll see that:

The tool must have a guide or other documentation in the Node.js GitHub organization or website;

Added

I propose to add a new guide to the existing collection 🆕.

The guide is about how could we use built-in tools to diagnose memory leaks.

Here is a list of topics I hope this guide will help on:

• basics of garbage collection
• what is the purpose of --trace-gc? and how could we interpret the output?
• how to perform heap snapshot?
• how to compare heap snapshot with Chrome dev tool?

⚠️ DISCLAIMER: I voluntarily simplify garbage collection concepts (that I didn't master myself). I don't know If it's a good idea or not, please share your thoughts on that. Note that my initial intention was to provide an introductory guide more than a deep dive.

Concern

• I'm not sure about how should we handle images and gifs (location, size ...)

[tony-go]

cc @nodejs/diagnostics

[RafaelGSS]

I think the initial idea of the diagnostics working group was to add those guides in https://github.com/nodejs/diagnostics to then elaborate a long guide to nodejs.org.

I feel we need to discuss it. What do you think?

I recommend you add it to the next diag-agenda. cc: @nodejs/diagnostics

EDIT1: I mean, I feel this guide would fit perfectly in: https://github.com/nodejs/diagnostics/tree/main/documentation/memory

[tony-go]

Hey @RafaelGSS 👋

Sorry, I was off the past week so I didn't answer quickly.

I think the initial idea of the diagnostics working group was to add those guides in https://github.com/nodejs/diagnostics to then elaborate a long guide to nodejs.org.

I feel we need to discuss it. What do you think?

I recommend you add it to the next diag-agenda. cc: @nodejs/diagnostics

This issue is still in the agenda we could discuss it at the next meeting 🙌 My only concern about keeping stuff in diag repo is that visibility/accessibility is limited. I'd like to expose each piece of the puzzle as soon as it's ready.

[tony-go]

As discussed in the last diagnostics WG meeting, we'll close this issue and merge the content into the diagnostic repository.