Designing Evolvable Web API with ASP. Read casually, "The Internet,the World Wide web,and HTTP"--http

HTTP

We will focus only on the parts related to creating Web APIs.

HTTP is an application-level protocol in information systems and is the backbone of the web. It was originally made by Berners-lee,

Roy Fielding and Henrik Frystyk Nielsen, a three-bit computer scientist. HTTP is

An interface is defined between the client and the server to transmit information across the network. It hides the realization of both sides of the fine

Section.

HTTP is designed to dramatically change the system, allowing a degree of latency and data obsolescence.

This design allows computer intermediate media, such as proxy servers, to coordinate communications, providing many benefits,

such as caching, compression, and navigation. These features of HTTP make it in the World Wide Web

Become a very ideal tool. It is dramatically changing and advancing with the inherent delay time

The development of network technology. It has withstood the test of time, and since its launch in 1996, it has been helping

The World Wide Web.

Cross HTTP 1.1

HTTP is also not static, it is also moving forward.

Prior to the existence of HTTP spec RFC 2616 There are some conceptual confusion, the IETF

Had a httpbis, but did not have much influence in the public, they later engaged in

HTTP 2.0 does not have much effect. Because Httpbis was going to replace

HTTP, but also provides a deeper understanding of HTTP, so we

It will be used as a basis.

HTTP Information exchange

HTTP-based systems, which, when exchanging information, are Request/response

In a way that is carried out in a stateless manner.

June please look:

The client makes a request

This request contains the HTTP version, the URI of a resource, the request header, the HTTP method, and a

An optional entity content. This request will be sent to the original server. After the server to see URIs

and the HTTP method to determine whether it can handle this information. If it can, it will look

The request header, and then processes the information according to the request header.

When the server finishes processing this information, the HTTP response response is generated, which contains

A representation of the resource.

June please look:

This response contains the HTTP version, the response header, and the optional entity body, a status code

and a description. Similar to receiving information from the server, the client will use its control information to check the sound

should be header, and then process this information and its contents.

Intermediarie Middleman

This process, which ignores an important part, intermediaries. Middleman.

HTTP is a schema that is based on the consideration of components or servers in the system. Let an HTTP

client sees server, is not necessary. Since the request will come to the server over a long distance,

It will encounter some middlemen,. They may be proxies or some may check

A component that HTTP requests or responds to and modifies or replaces information.

The middleman can immediately return a response and invoke the log record, or do not process it.

Middlemen can benefit from increased and enhanced communication, such as the cache that it returns from the server

The data is returned directly to the requesting side, which greatly improves the response time.

It can also be seen that the middle person can be located in the task place.

type of Middleman

In client and server-side communication, there are three types of intermediaries involved, and the client is visible

Of

• Proxy it will handle HTTP requests and responses for the client. Customer use of proxies is usually intentional.
• Gateway it will receive incoming HTTP information, convert the protocol to the server, and also send out the information

Converted to an HTTP protocol. It behaves like a server,

• Channels such as HTTPS

Here is the CDN mentioned in the original.