SSL faster at Savvii
by: Gijs Hovens
More and more Savvii customers are using HTTPS for their sites. This improves the safety of your site and is an organic ranking factor for Google. Google published that SSL is a ranking factor in approximately 2% of all search queries. They expect this number to rise.
A drawback of using SSL is that your site can get a little slower. Next to this, Varnish caching is not compatible with SSL. Joost de Valk from Yoast shedd some light on this topic in his presentation on our jointly organized WordPress Nijmegen Meetup (see his presentation (Dutch)). Luckily Savvii has taken some measures to improve the safety and speed of using SSL in comparison to most other hosting providers.
Measure 1: SPDY
The SPDY protocol (pronounced ‘speedy’) is developed by Google as an improvement on the HTTP protocol when combined with TLS (SSL). Unlike HTTP, SPDY opens a stream to transfer all assets simultaneously to the client. If you want to know more read the whitepaper.
Not all older browsers (IE 10 or older, Safari and Opera 7 or older) support SPDY. We have configured our servers to fall back to the standard HTTP(s) protocol in these cases. So your sites remain available to all visitors.
Measure 2: OSCP Stapling
OSCP Stapling is hard to explain in a basic way. When using TLS (SSL), your browser needs to perform lots of checks when validating a SSL certificate. By utilizing OSCP stapling this process is greatly shortened without compromising the security. If you are interested in the technical background we recommend reading this article.
Measure 3: STS Header Field
By utilizing a Strict-Transport-Security header no speed is gained. An STS directive is contained in the response header and tells the browser to keep using HTTPS to connect to the website for a specified period. This period is 2 years at Savvii.
Measure 4: SSL Session caching
This is something we have done from the beginning but it is good to mention it here anyway. We provide session identifiers and session tickets. By doing this only one full SSL handshake is necessary for the first asset, all later assets can be transferred by using a shorter handshake. This improves the speed of HTTPS.
Fast SSL in combination with Varnish caching
Varnish caching used to be not working in combination with SSL. Nowadays Varnisch cahing is working fine with SSL and of course it is available on our servers.
In short, at Savvii we do a lot to ensure that SSL certificates work as fast as possible on our servers. In addition, free DV certificates are available with our Let’s Encrypt integration.