SPDY is a protocol made by Google (who else) for transporting web content faster. It tries to solve the issue of reducing latency over SSL but maintaining the security that SSL traffic brings to an site. Recently Google announced that they would join forces and merge SPDY with HTTP/2. Where does that leave you?
So SPDY is already implemented into Nginx and Apache meaning that you can already start supporting it today. If you have a website that is running largely over SSL then you could potentially see much improvement in latency for the end user that has SPDY enabled browsers. In the case of DrupalDare a normal page load on the first page is around 50% faster with SPDY including all the internal resources (images, css, js).
Basically HTTP/2, the first major uphaul of the HTTP protocol since 1999, will be released almost as you read this. It will come with a lot of new goodies to speed up the web. It will be multiplexed, meaning that a single connection can handle parallel calls. It will be binary based instead of textbased so it can be parsed faster. It will have natural push techniques so the server can send the client data. All of it sounds like a real beauty.
Another factor is if you have Varnish front-facing the web. Since Varnish does not like playing with SSL, SPDY is basically out of the picture. The solution you can do is a reverse proxy in front of Varnish. So a double sandwich of Nginx with Varnish in the middle. The question is if that makes sense when you can speed things up directly with Nginx?
The problem though is that Nginx might not get support for HTTP/2 until the end of 2015. And for Apache it is hard to find any release date, but one can assume they will be a little bit faster then Nginx.
Secondly HTTP/2 is built upon SPDY, meaning that if you implement SPDY today the upgrade to HTTP/2 should hopefully be easy.
Bear in mind that the combination of security and low latency is becoming a real important SEO factor, something that SPDY helps solving. So besides the obvious of giving your end users a great fast secure experience when visiting your page it will boost your SEO as well.
I installed SPDY, users on drupal.org are complaing about drupal.org not implementing it. This post will be short and concise - you will find all the information in the links. Basically if it was my call - you should SPDY today if you haven't!
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