Table of contents
Distributed:
In a decentralized system, users are only responsible for managing their own computer systems, and there is no exchange and sharing of resources or information between independent systems. It's like a device without internet
Due to the repeated storage of a large amount of shared data in this mode , in addition to causing data redundancy , it is also easy to cause data inconsistency among departments within an organization .
At the same time, it will cause a large increase in the cost of hardware, support and operation and maintenance, so it will be eliminated early
centralized:
In a centralized environment, a host computer is used to store all the data of an organization, and users connect to and communicate with this computer system through devices to access the data
advantage:
Facilitate data sharing, eliminate data redundancy and inconsistency
shortcoming:
Reliability is not as good as decentralization, if the host fails, all systems will be paralyzed
distributed:
Distributed is a mixture of decentralized and centralized, similar to the computer network we have learned
It is a mode combining decentralized horizontal interaction and centralized vertical control
It combines the advantages of both decentralized and centralized
Facilitate data sharing, eliminate data redundancy and inconsistency, and also enhance fault tolerance
Give example
All data is stored in a dedicated database, which is centralized
The processing of data is controlled by the software of each department, which belongs to the distributed system.
C/S model
C/S (Client/Server) model is also called C/S mode
client and server mode
It is the model adopted by most network communication at present
Can be understood as two two applications in Dajiao
B/S model
B/S (Browse/Server) model is also called B/S mode
It is a web-based communication model that communicates using the HTTP hypertext transfer protocol
B/S is a special C/S model, the special feature is that the client of this model does not need to be developed by ourselves
Usually some kind of browser, such as IE, Chrome
The advantage of the B/S model is that a single computer can access any web server
Simply put, the web server can be changed at will, but the client is universal
There is no need to provide client applications specifically for different servers
P2P model
The P2P (Peer-to-Peer) model is also called peer-to-peer interconnection
Each networked device runs both client and server parts of an application
That is to say, an application acts as a client and a server at the same time
The advantages are convenient communication and low cost
The disadvantage is that the reliability is not as good as the C/S model
Summarize
Use the C/S model for front-end and back-end development
The layout of the server is often managed in a distributed form
For example, user data on the server side is managed in a centralized manner
Player data is stored in database applications (SQL Server, MySQL)
Server-side applications are managed using distributed
Account server, game server, chat server, cross-server PVP server and other distributed management
These server-side applications use the data in the database for logical processing