How much does the HTTP protocol know-about http1.x, HTTP2, Spdy

As the base protocol for Web development, we know that there are four letters of output HTTP on the browser, what does that mean?

This is the most basic HTTP protocol.

Waves June today for you to prepare a number of HTTP technology knowledge, to share with you.

Consider the example:

This loading interface, at least with the http/1.1, SPDY, HTTP/2 (H2) Three kinds of browser technology.

First say http/1.1:

HTTP1.1 (Hypertext Transfer Protocol version 1.1) Hypertext Transfer Protocol-release 1.1
It is a transfer protocol used to transmit hypertext over the Internet. It is an HTTP application protocol that runs on top of the TCP/IP protocol cluster, which makes the browser more efficient and reduces network transmission. In addition to including HTML files, any server has an HTTP resident program that responds to user requests. Your browser is an HTTP client that sends a request to the server, and when a start file is entered in the browser or a hyperlink is clicked, the browser sends an HTTP request to the server, which is sent to the IP address specified by the URL. The resident program receives the request and echoes the requested file after the necessary action is taken.

HTTP1.1 continuous connection. With this connection, it is possible to send a request and receive a response after establishing a TCP connection, and then send more requests and get more responses. By allocating the overhead of establishing and releasing TCP connections to multiple requests, for each request, The relative overhead caused by TCP is greatly reduced. Also, you can send pipeline requests, This means that a request can be sent before the response arrives after the request 1 is sent 2. You can also think that a connection sends multiple requests, and the client confirms that the connection is closed, and the server considers the requests to be from different clients.
The HTTP1.0 of the opposite
When the connection is established, the browser sends a request, after which a response message is sent back. The TCP connection is then freed. This is an early time when Web pages usually contain only HTML text, in which case this is enough. However, now the Web page generally also contains a large number of icons, Images and other very eye-pleasing content, so establishing a TCP connection simply transmits an icon, which can be costly.

Besides HTTP/2:

HTTP/2, the 2nd version of the Hypertext Transfer Protocol, is invariant for the basic semantics of either 1 or 2,http, such as Method semantics (get/pust/put/delete), Status codes (200/404/500, etc.), Range request,cacheing , authentication, URL path, the difference is mainly the following points:

HTTP2 is mainly for the following issues of HTTP1 optimization:

• Limited parallel capabilities

Maximum of 6 requests per source
The pipe does not work when it is actually used
Competitive TCP flow, forced fast retransmission (spurious retransmissions)
Additional handshake, memory buffer, etc.

• Client request queue

Team first Block
Deferred request distribution

• Higher protocol Load

Header information and cookies are about 800 bytes
HTTP meta data is not compressed

In addition, http/1.1 only allows the client to initiate unsolicited requests, and the server can only wait for the client to send the request, which is a shackle to meet the status of preload.

the advent of HTTP 2.0 has greatly improved Web performance compared to HTTP 1.x. The network latency is further reduced on the basis of full semantic compatibility with http/1.1. For front-end developers, there is no doubt that the front-end optimization work is reduced. This article summarizes the basic technical points of the HTTP 2.0 protocol, contacts the relevant knowledge, and explores how HTTP 2.0 can improve performance.


Emerged

HTTP/2: The future of the Internet This is an official demonstration by Akamai to illustrate the significant performance improvements in HTTP/2 compared to previous http/1.1. At the same time, request 379 pictures, from the load times of the comparison can be seen HTTP/2 in the speed advantage.

Again Spdy, this is a technology created by Google, HTTP/2 was not finalized at the beginning of the birth, so it is used to solve the transition period problem.

http/1.1 was set by RFC 2616 in 1999, and since then the entire internet has been based on it, with a total of 10 newer versions or alternative protocols, but some versions are considered to have improved space, especially performance. Google was also one of the companies trying to improve http/1.1, who released the Spdy agreement in 2009. In general, the chances of such an attempt to succeed are negligible because the Internet has a huge historical burden, but Google has a weapon that can make Spdy popular: Chrome. They built their own web site, modified Chrome to support Spdy, and users were attracted by their better performance, leaving the pressure on other websites and browser developers.

According to W3techs, at present, 3.4% of the world's more than 1.2 billion sites use the Spdy protocol. The ratio doesn't look high, but the list includes some of the biggest sites, including Google, Facebook, Yahoo!, Twitter, YouTube, WordPress, etc. This makes page traffic that is hosted by the Internet every day through the Spdy protocol accounts for a significant share of the total traffic count.

The IETF Httpbis Working group in charge of http/2.0 standardization, in a 2012 discussion, decided to use Spdy as a prototype for http/2.0, but at first they did not want to fully adopt it. Microsoft also made their own proposal, called the HTTP speed+mobility. Three years later, it seems that Spdy has won the competition, and it has been adopted by the Httpbis Working Group as http/2.0, and has entered the final stages of the standardized process.

As a result, Google announced that Spdy retired in 2016, in turn to adopt http/2.0. For Google's Web site and chrome, just a change of protocol name, the agreement itself does not change. The latest Chrome 40 has a SPDY/4 switch, and anyone interested in testing http/2.0 can open it. Google also intends to no longer allow Chrome to support the NPN protocol in favor of the ALPN protocol, and recommends that developers use the latest TLS extensions.

is a wave of software www.z01.com official website in the http/1.1 and http/2.0 under the agreement of the loading speed of the measured map, you can see the difference is more than 10 times times, it is worth deploying.

About the deployment of HTTP/2, first of all have high-quality servers (Win2016+ssl is the necessary prerequisite), but also need to have an excellent CMS support, in this regard, zoomla!-per-wave CMS is a domestic production site portal system leader, it is recommended.

PS: Following 2016, zoomla!-wave CMS fully enabled SSL, became the first to support the SSL financial level Web site content management system.

July 15, 2017, the official announcement of the Wave-based CMS: comprehensive for all users to provide HTTP/2 high-speed portal access and technical specifications services, and into the new zoomla!-wave CMS products, with which the establishment of stations, app generation, station groups, Office systems integrated, To build China's excellent website management system.

How much does the HTTP protocol know-about http1.x, HTTP2, Spdy