Will using both protocols on the same domain, serving the same website, make it indexed twice by search engines, and considered duplicate content?
If that so, what is the best way to avoid this negative effect in SEO. Should I make https on another subdomain like https://ssl.example.com instead of https://www.example.com with a different docroot? Or is it good enough to make the necessary 301 redirects from https to http for non-secure content and vice versa on the same docroot? What is the best practice here?