Showcasing some new profiling tools at the next WG meeting

[mafintosh]

With clinic, https://github.com/nearform/node-clinic, we've been working on some new fun and interesting ideas on how to profile and visualize async flow. It's getting to a state where we'd love to share some of stuff we've made so far with the diagnostics WG to get some feedback. I believe @mcollina and @AndreasMadsen also presented a very early version of it at the last summit

The tool itself profiles code like this:

const fs = require('fs')
const util = require('util')
const http = require('http')

const service = util.promisify(fs.readFile).bind(null, __filename)

const server = http.createServer(async function (req, res) {
  const [a, b, c] = await Promises.all(service(), service(), service())

  res.end(Buffer.concat([a, b, c]))
})

server.listen(3000)

And turns into a UI like this:

Where each bubble represents async/sync time spent on operations. The line between the bubbles represents the flow, with longer lines meaning longer latencies. Most of this is powered by async_hooks and trace events.

Would love to do a short demo at the next WG meeting if possible, on Wed the 2nd of May :)

[mhdawson]

Would love to see that but won't be able to make the next meeting.

[mmarchini]

Reminder @nodejs/diagnostics: if you want early access to this tool, reach out to @mafintosh or @mcollina.

I'm closing this issue since the tool was shown at the last meeting (congratulations btw, looks like a promising tool 😄). If you believe there's anything else to be discussed here feel free to reopen.