5.03 - HTTP/2

1 - Findings & Impacts

HTTP2 solves one of the major issues of HTTP 1.1: the need to open several successive connections to perform server requests. With HTTP/2, all requests can be made simultaneously while maintaining one open connection only. Furthermore, http2 allows:

• an automatic header compression
• a "push server" feature. With HTTP 1.1 when the browser requests the server, the HTML file is downloaded first then the JS files, the images and other CSS files. With HTTP/2 the server knows exactly which resource is needed to display the requested page.

2 - Recommendations

Step 1

Switching to HTTPS is a prerequisite (see relevant sheet)

2nd step

Configure your server for HTTP/2. Nginx and IIS support it natively, Apache will need the mod_spdy module. To save time you can go through the use of a CDN. These servers are usually configured to use HTTP/2.

The upgrade to HTTP/2 allows you to avoid going through all kinds of other implementations such as CSS file grouping, JS file compression and minification.