Compression
Compression can greatly decrease the size of the response body, thereby increasing the speed of a web app.
For high-traffic websites in production, it is strongly recommended to offload compression from the application server - typically in a reverse proxy (e.g., Nginx). In that case, you should not use compression middleware.
Use with Express (default)#
Use the compression middleware package to enable gzip compression.
First install the required package:
$ npm i --save compression
$ npm i --save-dev @types/compression
Once the installation is complete, apply the compression middleware as global middleware.
import * as compression from 'compression';
// somewhere in your initialization file
app.use(compression());
Use with Fastify#
If using the FastifyAdapter, you'll want to use fastify-compress:
$ npm i --save @fastify/compress
Once the installation is complete, apply the @fastify/compress middleware as global middleware.
import compression from '@fastify/compress';
// somewhere in your initialization file
await app.register(compression);
By default, @fastify/compress will use Brotli compression (on Node >= 11.7.0) when browsers indicate support for the encoding. While Brotli can be quite efficient in terms of compression ratio, it can also be quite slow. By default, Brotli sets a maximum compression quality of 11, although it can be adjusted to reduce compression time in lieu of compression quality by adjusting the BROTLI_PARAM_QUALITY between 0 min and 11 max. This will require fine tuning to optimize space/time performance. An example with quality 4:
import { constants } from 'zlib';
// somewhere in your initialization file
await app.register(compression, { brotliOptions: { params: { [constants.BROTLI_PARAM_QUALITY]: 4 } } });
To simplify, you may want to tell fastify-compress to only use deflate and gzip to compress responses; you'll end up with potentially larger responses but they'll be delivered much more quickly.
To specify encodings, provide a second argument to app.register:
await app.register(compression, { encodings: ['gzip', 'deflate'] });
The above tells fastify-compress to only use gzip and deflate encodings, preferring gzip if the client supports both.
