shuhei

const http = require("http");
const net = require("net");

const server = http.createServer((req, res) => {
  req.resume();
  res.end("hello");
});

server.keepAliveTimeout = 6 * 1000;
server.headersTimeout = 4 * 1000;

shuhei

const http = require('http');

const server = http.createServer((req, res) => {
  console.log('[server] request');
  setTimeout(() => {
    res.end('hello');
    console.log('[server] response');
  }, 3000);
});
server.listen(3000, () => {

shuhei

Benchmark of Node.js Histogram Libraries

This benchmark compares the following libraries:

• metrics@0.1.20 + mikejihbe/metrics#67
• measured-core@1.40.1
• hdr-histogram-js@1.1.4
• native-hdr-histogram@0.5.0

of:

shuhei

const a = {
    a: 1,
    b: null
};
const b = {
    a: 2,
    b: null
};
const c = {
    a: 2,

shuhei

function countChildren(el) {
  const children = el && el.children;
  if (!children) {
    return 0;
  }
  let count = 0;
  for (let i = 0; i < children.length; i++) {
    const child = children[i];
    count += 1;
    count += countChildren(child);

shuhei

const fs = require('fs');
const path = require('path');

class Node {
  constructor(start, end, depth) {
    this.start = start;
    this.end = end;
    this.middle = Math.floor((start + end) / 2);
    this.items = [];
    this.left = null;

shuhei

Fixing wrong symbols in Node.js CPU Frame Graphs

Motivation

I have been generating CPU Flame Graphs of Node.js applications with Linux perf command, and noticed that some of the graphs have suspicious labels. For example, with a sandbox project and Node 10.8.0, I got LazyCompile:*a.renderDOM /opt/app/node_modules/react-dom/cjs/react-dom-server.node.production.min.js:35 where it should have been something related to streams.

For example, the following is a stack trace from perf script that I used to genearte a CPU Flame Graph. 227bbdff955b has a label LazyCompile:*a.renderDOM, but it doesn't make much sense that React.renderDOM was called from _stream_readable.js and parsed JSON in it.

node 22640 56531.256247:   10101010 cpu-clock: 

shuhei

.PHONY: build

configure:
	@node-gyp configure

build:
	@node-gyp build

run:
	@node index.js

shuhei

gzsize

gzsize shows gzipped file sizes of files in your current working directory.

# For terminal
gzsize

# Markdown table
gzsize -m

shuhei

UV_THREADPOOL=100 node index.js

ab -c 100 -n 1000

htop