Introducing HTTP/2

In May 2015, the IETF ratified HTTP/2 as the latest version of the HTTP protocol. This marks the first enhancement to HTTP since HTTP 1.1 was published in 1997.

Screenshot of Microsoft Internet Explorer 3 running under Windows 95. Used with permission from Microsoft.

If you can remember using NetScape or Internet Explorer 3, you saw first-hand how websites and web applications evolved over this period from simple text-based pages with a handful of small images to the media-rich, highly interactive experiences we take for granted today.

In an effort to make the web experience more responsive to users, Google developed the SPDY protocol. SPDY manipulated the interaction between compatible browsers and servers to make page loading more efficient, and also enabled servers to push content to the browser before it was requested.

HTTP/2 is largely based on SPDY, establishing these mechanisms as a standard for compatibility across all browsers and webservers.

Why Upgrade to HTTP/2?

One word: Performance.

HTTP/2 is backwards compatible with older HTTP versions, but an HTTP/2 server affords users of HTTP/2 browsers a more responsive user experience. HTTP/2 accelerates page load times through:

  • HTTP header compression,
  • Loading page elements in parallel over a single TCP connection,
  • Pushing content from the server (instead of waiting for individual “GET” requests,
  • Avoiding head-of-line blocking

How to Upgrade to HTTP/2?

The Hard Way

The newest version of IIS (Windows 10/Server 2016) comes with HTTP/2 support, and other popular webservers (e.g. Apache, nginx) plan to release their HTTP/2 versions later in 2015. Turning on HTTP/2 today means replacing the server OS on every one of your Windows Servers to run the latest version of IIS version, or in the case of Apache, patching the source code to enable the HTTP/2 module.

The Easy Way

If the cost, effort, and risk of upgrading your entire webserver farm to the latest version relegates HTTP/2 to the “too hard basket,” NetScaler offers an easy low-risk alternative.

  1. Upgrade your NetScaler to 11.0 (or greater)
  2. Check that your NetScaler has an Enterprise or Platinum Licence
  3. Turn on HTTP/2 on the NetScaler (Easy Step-By-Step Instructions Here)

How Does NetScaler Bring HTTP/2 to Legacy Apps & Servers?

When you turn on HTTP/2 on the NetScaler, compatible browsers will  enjoy the enhanced performance of the new protocol. On the server side, the NetScaler proxies the browser sessions to the server using HTTP/1.x, so no server changes are necessary.

Just One Caveat

HTTP/2 incorporates security within the the HTTP protocol, where previously security was an add-on outside the HTTP session. Although the HTTP/2 standard doesn’t mandate security,  some browsers only support encrypted HTTP/2, making it a de-facto requirement. HTTP/2 therefore requires SSL hardware for maximum performance, and is only available on the MDX and SDX platforms.

How to Bring HTTP/2 Performance to Non-Compatible Browsers

The latest versions of Chrome, Safari, and Firefox support HTTP/2, but users of older versions or other browsers such as Internet Explorer are not so fortunate. To ensure the fastest possible browser experience for these users, be sure to enable  NetScaler’s HTTP Optimisation features. NetScaler HTTP Optimisation improves the efficiency of the interaction between the browser and server using techniques such as HTTP compression, content caching, and streamlining delivery of content such as style sheets and javascript.