Measuring latency from the client side using Chrome DevTools and N|Solid

Almost every modern web browser includes a powerful suite of developer tools. In our previous blog-post we covered __How to Measure Node.js server response time with N|Solid__, read more ???? HERE.

The developer tools have a lot of capabilities, from inspecting the current HTML-CSS and Javascript code to inspecting the current ongoing network communication client-server.

To open the devtools and analyze the network, you can go to:

“More Tools” > “Developer Tools” > “Network”

Being on the devtools screen now, you can visit your Fastify API(or express) http://localhost:3000 after you get an HTTP response, you will see the request itself, the HTTP status code, the response size, and the response time.

GIF 1 – devtools.gif

An explanation for the time measured by the Chrome DevTools, HERE.

Let’s measure the Client-Side Latency.

Remove the delay timer logic on your application and restart the Node.js process.

import Fastify from “fastify”;

const fastify = Fastify({
logger: true,
});

// Declare the root route and delay the response randomly
fastify.get(“/”, async function (request, reply) {
return { delayTime: 0 };
});

// Run the server!
fastify.listen({ port: 3000 }, function (err, address) {
if (err) {
fastify.log.error(err);
process.exit(1);
}
});

NOTE: Discover another useful code snippet in our ‘Measure Node.js server response time with N|Solid’ article! This time, learn how to simulate server-side latency to further test your application’s performance. Check it out: ???? HERE

After this, you will get the fastest response times of ~1 ms, I was able to execute 139k requests in 10 secs using autocannon.

npx autocannon localhost:3000

The main point here is to see how it behaves when we have a poor internet connection on the client side and the best possible performance on the server side; for this, we can simulate high latency and slow internet connections on the client side, using Chrome devtools which has this option out of the box.

Simulate Client-Side latency

In the Chrome Devtools:

Go to the “Network Conditions” option > Select the option “Network Throttling” > Set it to __“Slow 3G”__.

If you request your browser to the URL http://localhost:3000/, you’ll see a long response time, in our case, __~2 seconds__.

This response time doesn’t mean the server takes that long to process the request and return an answer that was the amount of time that the answer took to transfer over the network till it arrived at the client side.

If you check your Fastify logs of the N|Solid metrics, you’ll see the server only took ~1 ms to return.

Check your logs with N|Solid
HERE

In our case, the response time was 0.3 ms

“responseTime”:0.3490520715713501

Can I improve/help the client-side latency?

Well, it is possible to improve the user experience on client-side devices with high latency when you use a Content Delivery Network to cache content on edge locations geographically near to users’ devices; even implementing some simple compression mechanism will improve the load times on users’ devices with high latency.

Look at this Jonas, our Principal OSS Engineer, blog-post and see ???????? __How to create a fast SSR application__.

Connect with NodeSource

If you have any questions, please contact us at [email protected] or through this form.

To get the best out of Node.js and experience the benefits of its integrated features, including OpenTelemetry support, SBOM integration, and machine learning capabilities. Sign up for a free trial and see how N|Solid can help you achieve your development and operations goals. #KnowyourNode

Experience the Benefits of N|Solid’s Integrated Features
Sign up for a Free Trial Today

Why Svelte is converting TypeScript to JSDoc

#​638 — May 11, 2023

Read on the Web

JavaScript Weekly

The JavaScript Ecosystem is Delightfully Weird — There are plenty of examples of how JavaScript is weird but Sam focuses on the why. If you’ve been a JS developer for many years you’ll have seen it go through many phases and morph to fit its environment. Sam paints the big picture, concluding with a talk Dan Abramov gave yesterday called “React from Another Dimension.”

Sam Ruby

The New JS Features Coming in ECMAScript 2023 — The next JavaScript update brings smaller additions familiar from other languages, but there are more significant developments waiting in the wings. 

Mary Branscombe (The New Stack)

Full Stack for Front-End Engineers with Jem Young (Netflix) — Learn what it means to become a well-rounded full-stack engineer with this hands-on video course. You’ll dive into servers, work with the command line, understand networking and security, set up continuous integration and deployment, manage databases, build containers, and more.

Frontend Masters sponsor

Vue 3.3 ‘Rurouni Kenshin’ Released — Named after a popular manga series, the latest release of Vue is focused on developer experience improvements, particular for those using TypeScript.

Evan You

John Komarnicki says ▶️ Vue 3.3’s defineModel macro will change the way you write your components.

Next.js 13.4 Released — Despite the minor version bump, this is a big release for the popular React framework. The new app router and its improved approach to filesystem based routing is now offered as a stable feature, with a new concept of server actions being introduced in alpha as a way to mutate data on the server without needing to create an in-between API layer.

Tim Neutkens and Sebastian Markbåge

⚡️ IN BRIEF:

???? Svelte is converting from TypeScript to JSDoc (example).. sort of. Rich Harris popped up on Hacker News to provide some all important context but the ultimate result will be smaller package sizes and a better experience for Svelte’s maintainers.

React now has official ‘canary’ releases if you want to use newer features than in the stable releases but still be on an officially supported channel.

Newly released Firefox 113 lets you override JS files in its debugger.

No stranger to controversy, Ruby on Rails’s David Heinemeier Hansson (DHH) tweeted: ???? “TypeScript sucked out much of the joy I had writing JavaScript.”

RELEASES:

Glint 1.0 – TypeScript powered tooling for Glimmer / Ember templates.

Elementary 2.0 – JS/C++ library for building audio apps.

???? Articles & Tutorials

ES2023’s New Array Copying Methods — The newest ECMAScript spec introduces some new methods on Array that you’ll eventually find useful in your own programs. Phil gives us the tour.

Phil Nash

Private Class Fields Considered Harmful“As a library author, I’ve decided to avoid private class fields from now on and gradually refactor them out of my existing libraries.” Why? Well, that’s the interesting part..

Lea Verou

▶  I’m Done with React — Going from least-to-most important, the reasons this developer isn’t choosing React for future projects make for interesting watching, particularly if you too are overwhelmed by upheaval in the React world. Solid is one of the alternatives he has warmed to.

Adam Elmore

Constraining Language Runtimes with Deterministic Execution — Explore various challenges encountered while using different language runtimes to execute workflow code deterministically.

Temporal Technologies sponsor

Running JavaScript in Rust with Deno — Deno’s use of Rust makes it a natural choice if you’re building a Rust app and want to integrate a JavaScript engine.

Austin Poor

Regular Expressions in JavaScript — Powerful but often misunderstood, many will benefit from this roundup of the potential regexes offer to JavaScript developers.

Adebayo Adams

How to Measure Page Loading Time with the Performance API — The Performance API is a group of standards used to measure the performance of webapps supported in most modern browsers.

Silvestar Bistrović

How to Build a JS VST or Audio Unit Plugin on macOS — VSTs and Audio Units are both types of audio plugins for audio editing software and they’re usually built in C or C++. This tutorial doesn’t dig into the audio side of things, but more the practicalities of packaging things up to get started.

Chris Mendez

An Introduction to the Bun Runtime — If you’ve not yet played with the newest entrant into the JS runtime space, this is a high level overview.

Craig Buckler

2023 State of the Java Ecosystem

New Relic sponsor

Configuring ESLint, Prettier, and TypeScript Together

Josh Goldberg

DestroyRef: Your New Angular 16 Friend

Ion Prodan

Why Astro is My Favorite Framework

Ryan Trimble

???? Code & Tools

file-type 18.4: Detect the File Type of a Buffer, Uint8Array or ArrayBuffer — For example, give it the raw data from a PNG file, and it’ll tell you it’s a PNG file. Uses magic numbers so is targeted solely at non text-based formats.

Sindre Sorhus

Learn How the Rising Trend of Malicious Packages Can Affect Your Apps — Keep your applications secure with Snyk’s article on the increasing number of malicious OS packages and ways to mitigate these risks.

Snyk sponsor

Livefir: Build Reactive HTML Apps with Go and Alpine.js — Go isn’t a language that often pops up in the context of the frontend, but this is a neat integration between Go on the backend and Alpine.js up front.

Adnaan Badr

JZZ.js: A Developer Friendly MIDI library — For both browsers and Node, JZZ.js provides an abstraction over working with MIDI related concepts. There are many examples, but the easter egg in the top left is our favorite.

Sema / Jazz-Soft

htmlparser2 9.0: A ‘Fast and Forgiving’ HTML and XML Parser — Consumes documents and calls callbacks, but it can generate a DOM as well. Works in both Node and browser.

Felix Böhm

cRonstrue: Library to Convert cron Expressions into Human-Readable Form — Given something like */5 * * * *, it’ll return “Every 5 minutes”. No dependencies.

Brady Holt

Knip: Find Unused Files, Dependencies and Exports in TypeScript Projects — Being Dutch for “snip” is appropriate as Knip can trim away things that aren’t being used in your project.

Lars Kappert

jsPlumb 6.1
↳ Visual connectivity for webapps.

gridstack.js 8.1
↳ Build interactive dashboards quickly.

???? Jobs

Find JavaScript Jobs with Hired — Hired makes job hunting easy-instead of chasing recruiters, companies approach you with salary details up front. Create a free profile now.

Hired

Team Lead Web Development — Experienced with Node, React, and TS? Join us and lead a motivated team of devs and help grow and shape the future of our web app focused on helping millions explore the outdoors.

Komoot

????‍???? Got a job listing to share? Here’s how.

???? Don’t tell Satya Nadella..

Fake Windows 11 in Svelte — This is a cute little side project, and the code is available too. The most common complaint I’ve seen is that it’s actually more responsive than the real Windows.. ???? Be sure to check out both ‘VS Code’ and ‘Microsoft Edge’ in this environment.

Yashash Pugalia

???? Prefer Windows XP? Maybe RebornXP is more for you. Complete with the classic starting up sound!