The book is outdated but still has a tone of useful information ant it fully covers HTTP 1.1, which is still the most up-to-date version of HTTP protocol. Accor

The book is outdated but still has a tone of useful information ant it fully covers HTTP 1.1, which is still the most up-to-date version of HTTP protocol. According to W3Techs only 1.2% of all websites support HTTP/2 (August 2015).