hook-test.js

'use strict';

const fs = require('fs');
const AH = require('async_hooks');
const net = require('net');

const { inspect } = require('util');
function log(...args) {
  fs.writeSync(process.stdout.fd, `${args.map(x => inspect(x, { depth: null, colors: true })).join(' ')}\n`);
}

const hook = AH.createHook({
  init(id, type, pid) {
    if (type.startsWith('TCP')) log(type, { id, pid });
  }
});
hook.enable();

for (let i = 0; i < 5; i++) {
  (j => {
    // pool.pull((err, conn) => {
    const conn = net.connect(11211);
    conn.on('connect', () => {
      log('connect', { j, id: AH.executionAsyncId() });
      conn.setEncoding('utf8');
      conn.on('data', chunk => {
        if (!chunk.includes('END')) return;
        conn.end();
        log('data', { j, id: AH.executionAsyncId() });
      });
      conn.write('stats\n');
    });
  })(i);
}