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Improving your applications with AbortController ✨ |
Simon Plenderleith
NodeConf Remote 2021
Oct. 19th, 2021
Slides and code at
Independent Node.js consultant and educator
I help developers level up with Node.js at simonplend.com/blog
Author of Express API Validation Essentials
expressapivalidation.com
🍦 Problems at Ice Cream Corp
🍦 Performance testing
🍦 Menu Service v2... ?
🍦 The Abort API
🍦 Menu Service v3
🍦 Abort API support in Node.js
Photo by Markus Spiske on Unsplash
Photo by Pawel Janiak on Unsplash
import Fastify from "fastify";
const app = Fastify();
app.get("/stock", function (request, reply) {
const stock = [
{ id: "cf93d53f-7f60-4c9d-a543-ef217a09269b", name: "Cookies 'n' Cream", stock: 8532 },
{ id: "41373bb6-e6fb-4606-8f01-1cd24e228939", name: "Neopolitan", stock: 0 },
{ id: "8e884a8d-ae04-4518-80b7-377ee5bcecc6", name: "Pistachio", stock: 6437 }
];
const delay = Math.floor(Math.random() * 10000);
setTimeout(() => {
reply.send({ stock, delay });
}, delay);
});
await app.listen(4000);import fetch from "node-fetch";
import Fastify from "fastify";
async function makeRequest(url) {
const response = await fetch(url);
const responseData = await response.json();
return responseData;
}
const app = Fastify();
app.get("/menu", async function (request, reply) {
const stockServiceEndpoint = "http://stock-service.icecreamcorp.net:4000/stock";
const stockServiceResponse = await makeRequest(stockServiceEndpoint);
reply.send({ stockServiceResponse });
});
await app.listen(3000);
Running 60s test @ http://menu-service.icecreamcorp.net:3000/menu
100 connections
┌─────────┬────────┬─────────┬─────────┬─────────┬────────────┬────────────┬──────────┐
│ Stat │ 2.5% │ 50% │ 97.5% │ 99% │ Avg * │ Stdev │ Max │
├─────────┼────────┼─────────┼─────────┼─────────┼────────────┼────────────┼──────────┤
│ Latency │ 244 ms │ 4862 ms │ 9718 ms │ 9900 ms │ 4898.42 ms │ 2941.22 ms │ 10000 ms │
└─────────┴────────┴─────────┴─────────┴─────────┴────────────┴────────────┴──────────┘
┌───────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┐
│ Stat │ 1% │ 2.5% │ 50% │ 97.5% │ Avg * │ Stdev │ Min │
├───────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┤
│ Req/Sec │ 6 │ 8 │ 19 │ 27 │ 19.15 │ 4.63 │ 6 │
└───────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┘
Req/Bytes counts sampled once per second.
1k requests in 60.03s, 539 kB read
3 errors (3 timeouts)
Running 60s test @ http://menu-service.icecreamcorp.net:3000/menu
100 connections
┌─────────┬────────┬─────────┬─────────┬─────────┬───────────┬───────────┬─────────┐
│ Stat │ 2.5% │ 50% │ 97.5% │ 99% │ Avg * │ Stdev │ Max │
├─────────┼────────┼─────────┼─────────┼─────────┼───────────┼───────────┼─────────┤
│ Latency │ 253 ms │ 1004 ms │ 1024 ms │ 1146 ms │ 957.63 ms │ 176.57 ms │ 1217 ms │
└─────────┴────────┴─────────┴─────────┴─────────┴───────────┴───────────┴─────────┘
┌───────────┬─────────┬───────┬───────┬─────────┬─────────┬────────┬─────────┐
│ Stat │ 1% │ 2.5% │ 50% │ 97.5% │ Avg * │ Stdev │ Min │
├───────────┼─────────┼───────┼───────┼─────────┼─────────┼────────┼─────────┤
│ Req/Sec │ 13 │ 100 │ 105 │ 112 │ 103.47 │ 12.1 │ 13 │
└───────────┴─────────┴───────┴───────┴─────────┴─────────┴────────┴─────────┘
Req/Bytes counts sampled once per second.
612 2xx responses, 5596 non 2xx responses
6k requests in 60.03s, 1.97 MB read
A JavaScript API which consists of two classes:
AbortController and AbortSignal
const controller = new AbortController();
const signal = controller.signal;
signal.addEventListener("abort", () => {
console.log("The abort signal was triggered");
}, { once: true });
controller.abort();The Abort API originated in the Web Platform
Microsoft Edge 16 was the first browser to implement the Abort API in October 2017.
Now all major browsers support it.
Source: caniuse.com
Stable support in Node.js since v15.4.0, released in December 2020.
- Greater control over the behaviour of our application
- Free up system or network resources the application is using
- Ability to "fail fast"
- Potential improvement to application performance
Photo by David Becker on Unsplash
import fetch from "node-fetch";
const cancelRequest = new AbortController();
fetch("https://jsonplaceholder.typicode.com/posts", {
signal: cancelRequest.signal
})
.then(response => response.json())
.then(responseData => console.log(responseData))
.catch(error => console.error(error));
cancelRequest.abort();$ node node-fetch-with-abortsignal.js
file:///dev/node_modules/node-fetch/src/index.js:56
const error = new AbortError('The operation was aborted.');
^
AbortError: The operation was aborted.
at abort (file:///dev/node_modules/node-fetch/src/index.js:56:18)
at EventTarget.abortAndFinalize (file:///dev/node_modules/node-fetch/src/index.js:75:4)
at EventTarget.[nodejs.internal.kHybridDispatch] (node:internal/event_target:562:20)
at EventTarget.dispatchEvent (node:internal/event_target:504:26)
at abortSignal (node:internal/abort_controller:97:10)
at AbortController.abort (node:internal/abort_controller:122:5)
at file:///dev/abort-api/node-fetch-with-abortsignal.js:12:16
at ModuleJob.run (node:internal/modules/esm/module_job:183:25)
at async Loader.import (node:internal/modules/esm/loader:178:24)
at async Object.loadESM (node:internal/process/esm_loader:68:5) {
type: 'aborted'
}
Running 60s test @ http://menu-service.icecreamcorp.net:3000/menu
100 connections
┌─────────┬────────┬─────────┬─────────┬─────────┬──────────┬───────────┬─────────┐
│ Stat │ 2.5% │ 50% │ 97.5% │ 99% │ Avg * │ Stdev │ Max │
├─────────┼────────┼─────────┼─────────┼─────────┼──────────┼───────────┼─────────┤
│ Latency │ 282 ms │ 1006 ms │ 1116 ms │ 1167 ms │ 967.9 ms │ 172.98 ms │ 1251 ms │
└─────────┴────────┴─────────┴─────────┴─────────┴──────────┴───────────┴─────────┘
┌───────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┬─────────┐
│ Stat │ 1% │ 2.5% │ 50% │ 97.5% │ Avg * │ Stdev │ Min │
├───────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┼─────────┤
│ Req/Sec │ 4 │ 78 │ 104 │ 111 │ 102.57 │ 13.55 │ 4 │
└───────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────┘
Req/Bytes counts sampled once per second.
614 2xx responses, 5540 non 2xx responses
6k requests in 60.03s, 1.94 MB read
- Capture metrics of how many requests we're aborting
- Back off making requests to the Stock Service
- Prioritise improving the Stock Service
| v16.x | >= v14.17.0 | Older versions | |
|---|---|---|---|
AbortController +AbortSignal classes |
✅ | Experimental | Use abort-controller package |
| Node.js core APIs which accept AbortSignal |
✅ | ✅ | ❌ |
Enable abort classes with flag e.g. node --experimental-abortcontroller server.js
OR npm install abort-controller and:
import AbortController from "abort-controller";child_process.execchild_process.execFilechild_process.forkchild_process.spawn
dgram.createSocket
events.onevents.once
::right::
fs.readFilefs.watchfs.writeFile
http.requesthttps.request
http2Session.request
timers/promises.setImmediatetimers/promises.setTimeout
readline.Interfacereadline.createInterface
- Node Fetch
- Undici
- Axios - v0.22.0 (released on Oct 1st 2021) - Details in README
- Piscina - The Node.js worker pool
- AWS SDK for JavaScript - The official AWS SDK
- dockerode - Node.js module for Docker's Remote API
- James Snell for sharing the
Promise.race()setTimeout pattern - For review and feedback on this talk:
- For sharing libraries with support for
AbortSignal:
layout: image-right image: 'https://images.unsplash.com/photo-1537420327992-d6e192287183?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=2400'
Photo by Casey Horner on Unsplash