Blogmarks tagged nodejs
Filters: Type: blogmark × nodejs × Sorted by date
Using Rust in non-Rust servers to improve performance (via) Deep dive into different strategies for optimizing part of a web server application - in this case written in Node.js, but the same strategies should work for Python as well - by integrating with Rust in different ways.
The example app renders QR codes, initially using the pure JavaScript qrcode package. That ran at 1,464 req/sec, but switching it to calling a tiny Rust CLI wrapper around the qrcode crate using Node.js spawn() increased that to 2,572 req/sec.
This is yet another reminder to me that I need to get over my cgi-bin era bias that says that shelling out to another process during a web request is a bad idea. It turns out modern computers can quite happily spawn and terminate 2,500+ processes a second!
The article optimizes further first through a Rust library compiled to WebAssembly (2,978 req/sec) and then through a Rust function exposed to Node.js as a native library (5,490 req/sec), then finishes with a full Rust rewrite of the server that replaces Node.js entirely, running at 7,212 req/sec.
Full source code to accompany the article is available in the using-rust-in-non-rust-servers repository.
Announcing Deno 2. The big focus of Deno 2 is compatibility with the existing Node.js and npm ecosystem:
Deno 2 takes all of the features developers love about Deno 1.x — zero-config, all-in-one toolchain for JavaScript and TypeScript development, web standard API support, secure by default — and makes it fully backwards compatible with Node and npm (in ESM).
The npm support is documented here. You can write a script like this:
import * as emoji from "npm:node-emoji";
console.log(emoji.emojify(`:sauropod: :heart: npm`));And when you run it Deno will automatically fetch and cache the required dependencies:
deno run main.js
Another new feature that caught my eye was this:
deno jupyternow supports outputting images, graphs, and HTML
Deno has apparently shipped with a Jupyter notebook kernel for a while, and it's had a major upgrade in this release.
Here's Ryan Dahl's demo of the new notebook support in his Deno 2 release video.
I tried this out myself, and it's really neat. First you need to install the kernel:
deno juptyer --install
I was curious to find out what this actually did, so I dug around in the code and then further in the Rust runtimed dependency. It turns out installing Jupyter kernels, at least on macOS, involves creating a directory in ~/Library/Jupyter/kernels/deno and writing a kernel.json file containing the following:
{
"argv": [
"/opt/homebrew/bin/deno",
"jupyter",
"--kernel",
"--conn",
"{connection_file}"
],
"display_name": "Deno",
"language": "typescript"
}That file is picked up by any Jupyter servers running on your machine, and tells them to run deno jupyter --kernel ... to start a kernel.
I started Jupyter like this:
jupyter-notebook /tmp
Then started a new notebook, selected the Deno kernel and it worked as advertised:
import * as Plot from "npm:@observablehq/plot";
import { document, penguins } from "jsr:@ry/jupyter-helper";
let p = await penguins();
Plot.plot({
marks: [
Plot.dot(p.toRecords(), {
x: "culmen_depth_mm",
y: "culmen_length_mm",
fill: "species",
}),
],
document,
});openai/openai-realtime-console. I got this OpenAI demo repository working today - it's an extremely easy way to get started playing around with the new Realtime voice API they announced at DevDay last week:
cd /tmp
git clone https://github.com/openai/openai-realtime-console
cd openai-realtime-console
npm i
npm start
That starts a localhost:3000 server running the demo React application. It asks for an API key, you paste one in and you can start talking to the web page.
The demo handles voice input, voice output and basic tool support - it has a tool that can show you the weather anywhere in the world, including panning a map to that location. I tried adding a show_map() tool so I could pan to a location just by saying "Show me a map of the capital of Morocco" - all it took was editing the src/pages/ConsolePage.tsx file and hitting save, then refreshing the page in my browser to pick up the new function.
Be warned, it can be quite expensive to play around with. I was testing the application intermittently for only about 15 minutes and racked up $3.87 in API charges.
The first four Val Town runtimes
(via)
Val Town solves one of my favourite technical problems: how to run untrusted code in a safe sandbox. They're on their fourth iteration of this now, currently using a Node.js application that launches Deno sub-processes using the node-deno-vm npm package and runs code in those, taking advantage of the Deno sandboxing mechanism and terminating processes that take too long in order to protect against while(true) style attacks.
A framework for building Open Graph images. GitHub’s new social preview images are generated by a Node.js script that fetches data from their GraphQL API, generates an HTML version of the card and then grabs a PNG snapshot of it using Puppeteer. It takes an average of 280ms to serve an image and generates around 2 million unique images a day. Interestingly, they found that bumping the available RAM from 512MB up to 513MB had a big effect on performance, because Chromium detects devices on 512MB or less and switches some processes from parallel to sequential.
Deno 1.0. Deno is a new take on server-side JavaScript from a team lead by Ryan Dahl, who originally created Node.js. It’s built using Rust and crammed with fascinating ideas—like the ability to import code directly from a URL.
elasticsearch-dump. Neat open source utility by TaskRabbit for importing and exporting data in bulk from Elasticsearch. It can copy data from one Elasticsearch cluster directly to another or to an intermediary file, making it a swiss-army knife for migrating data around. I successfully used the “docker run” incantation to execute it without needing to worry about having the correct version of Node.js installed.
github-trending-repos (via) This is a really clever hack: Vitaliy Potapov built a system for subscribing to a weekly digest of trending GitHub repos in your favourite languages entirely on top of the existing GitHub issues notification system. Find the issue for your particular language and hit “subscribe” and you’ll get an email (or push notification depending on how you get your issue notifications) once a week with the latest trends. The implementation is a 220 line Node.js script which runs on a daily and weekly schedule using Circle CI, so Vitaliy doesn’t even have to host or pay for any of the underlying infrastructure. It’s brilliant.
Building a Full-Text Search App Using Docker and Elasticsearch. Deep, comprehensive tutorial from Patrick Triest showing how to use docker-compose to run three containers (Node API, nginx static content, elasticsearch) and then use that to build a neat Vue.js web search UI against 100 books from Project Gutenberg.
now-ab. Intriguing example of a Zeit Now microservice: now-ab is a Node.js HTTP proxy which proxies through to one of two or more other Now-deployed applications based on a cookie. If you don’t have the cookie, it picks a backend at random and sets the cookie. Admittedly this is the easiest part of implementing A/B testing (the hard part is the analytics: tracking exposures and conversions) but as an example of a microservice architectural pattern this is fascinating.
ZEIT – 6x Faster Now Uploads with HTTP/2 (via) Fantastic optimization write-up by Pranay Prakash. The Now deployment tool works by computing a hash for every local file in a project, then uploading just the ones that are missing. Pranay switched to uploading over HTTP/2 using the fetch-h2 library and got a 6x speedup for larger projects.
Live htop. Neat, simplest-thing-that-could-possibly-work implementation of a tool that continually pipes the output of the htop command to a browser over a WebSocket. The htopgen.sh scripts loops every 2 seconds, runs htop, pipes it through a utility to convert the output to HTML and writes that to a file. Then the server.js Node.js script watches for changes to that file and pipes the entire file contents to the browser via socket.io. The index.html page in the browser subscribes to the WebSocket and updates the entire page using innerHTML every time it receives an event.
Carbon (via) Beautiful little tool that you can paste source code into to generate an image of that code with syntax highlighting applied, ready to be tweeted or shared anywhere that lets you share an image. Built in Node and next.js, with image generation handled client-side by the dom-to-image JavaScript library which loads HTML into a SVG foreignObject (sadly not yet supported by Safari) and uses that to populate a canvas and produce a PNG.
nodejitsu’s node-http-proxy (via) Exactly what I’ve been waiting for—a robust HTTP proxy library for Node that makes it trivial to proxy requests to a backend with custom proxy behaviour added in JavaScript. The example app adds an artificial delay to every request to simulate a slow connection, but other exciting potential use cases could include rate limiting, API key restriction, logging, load balancing, lint testing and more besides.
pdf.js. A JavaScript library for creating simple PDF files. Works (flakily) in your browser using a data:URI hack, but is also compatible with server-side JavaScript implementations such as Node.js.
Parsing file uploads at 500 mb/s with node.js. Handling file uploads is a real sweet spot for Node.js, especially now it has a high performance Buffer API for dealing with binary chunks of data. Felix Geisendörfer has released a new library called “formidable” which makes receiving file uploads (including HTML5 multiple uploads) easy, and uses some clever algorithmic tricks to dramatically speed up the processing of multipart data.
A HTTP Proxy Server in 20 Lines of node.js. Proxying is definitely a sweet spot for Node.js. Peteris Krummins takes it a step further, adding host blacklists and an IP whitelist as configuration files and using Node’s watchFile method to automatically reload changes to them.
Step for Node.js. A further iteration on the attempts to make callback-based programming in Node.js easier to manage, this time making clever use of the ’this’ keyword to represent the next callback in the chain.
webhook-relay. Another of my experiments with Node.js: webhook-relay is a self-contained queue and webhook request sending agent. Your application can POST to it specifying a webhook alert to be sent off, and webhook-relay will place that request in an in-memory queue and send it on its own time, avoiding the need for your main application server to block until the outgoing request has been processed.
Node.js, redis, and resque (via) Paul Gross has been experimenting with Node.js proxies for allowing web applications to be upgraded without missing any requests. Here he places all incoming HTTP requests in a redis queue, then has his backend Rails servers consume requests from the queue and push the responses back on to a queue for Node to deliver. When the backend application is upgraded, requests remain in the queue and users see a few seconds of delay before their request is handled. It’s not production ready yet (POST requests aren’t handled, for example) but it’s a very interesting approach.
kriszyp’s node-promise. Another elegant approach to managing asynchronous flows in Node, including running things both in parallel and serial.
“Do” it fast! Tim Caswell’s Do library has been upgraded for compatibility with Node v0.1.30, and now has a clever Do.convert() method which wraps Node’s low-level APIs with the Do libraries “continuable” abstraction.
node-v0.1.30 (via) A very significant new release of Node.js: the Twisted/Dojo-style Promise abstraction has been removed entirely, causing backwards incompatible changes to a bunch of core APIs. This means the pseudo-blocking Promise.wait() method is gone too, making it even harder to accidentally block your event loop. Instead, user-level libraries are encouraged to add Promise-style abstractions. I’m pleased to see Node sticking to the low-level stuff.
do. A library for Node that adds a higher level abstraction for dealing with chained and parallel callbacks.
How To Node. New blog about Node.js, with a superb series of tutorials aimed at both experienced and new JavaScript developers. The stuff on managing callbacks (including running them in both series and parallel) is pretty eye-opening.
dogproxy. Another of my experiments with Node.js—this is a very simple HTTP proxy which addresses the dog pile effect (also known as the thundering herd) by watching out for multiple requests for a URL that is currently “in flight” and bundling them together.
Hot Code Loading in Node.js. Blaine Cook’s patch for Node.js that enables Erlang-style hot code loading, so you can switch out your application logic without restarting the server or affecting existing requests. This could make deploying new versions of Node applications trivial. I’d love to see a Node hosting service that allows you to simply upload a script file and have it execute on the Web.