Three-tier architecture software development

Technical Analysis of Three-tier Architecture in Software Development

The three-tier architecture technology is actually equivalent to adding an "intermediate layer" between the client and the database, which can also be called the component layer. This "middle layer" is not the middle layer in the actual physical sense, but refers to the logical middle layer, which puts business rules, data access, legality verification and other work in the application into the middle layer for processing. The client no longer directly interacts with the database, but establishes a connection through the middle layer, and then the middle layer interacts with the database, and finally realizes the data interaction between the client and the database.

Rules for Three-tier Architecture Software Technology

In the three-layer architecture technology of software development, the fourth layer of data entity layer is the basic data source, an indispensable layer, and the basis of software operation. Its operation effect depends on the rationality of computer hardware and database design. sex. As for the other three layers, it is not called a three-tier architecture as long as the project is divided into presentation layer, business logic layer and data access layer, and some agreed rules must be followed between these three layers:

(1) The presentation layer is only an interface for connecting with users, so it can be transplanted to other projects with similar environments.

(2) The data entity layer can only read data through the data access layer, and other layers cannot directly read data from the data entity layer.

(3) The data access layer can only be used as an intermediate layer for reading database entities, but cannot perform any business logic processing operations.

(4) Software design should focus on the business logic layer, not the data access layer or data entity layer, let alone the presentation layer. In the business logic layer, all business logic operations should be implemented in an object-oriented manner.

(5) All data in the data layer should be independent of the system to a certain degree of abstraction.

(6) When designing, all remote object technologies should take into account the load balancing between different servers and multiple servers for clustering.

(7) Any of these three modules can run on different servers.

Whether a project requires a three-tier design depends first on the complexity of the project. In fact, many projects only need to edit one WebApplication to realize all the functions, and no more complex technology is needed at all. Only really complex projects need to use three-tier architecture technology for design and development.

Advantages of three-tier architecture technology

By understanding the working principle of the three-tier architecture technology, we can get the advantages of the software developed through the three-tier architecture technology.

(1) The structure is clear and the coupling degree is low. In the three-tier architecture technology, the layers are distinct, the structure between the layers is clear, the software writers have a clear division of labor, and there are not many connections between the layers, reducing the dependencies between the layers, and the writers can only focus on the entire structure. A certain layer, thus greatly avoiding the coupling degree problem existing in the software developed by the two-layer technology.

(2) High maintainability and high scalability. The software developed with three-tier architecture technology greatly reduces maintenance costs and maintenance time during later maintenance. The function change and upgrade of any part of the software only needs to change the design and writing of a certain layer, without making changes to the entire system, unlike software developed with two-layer technology, where a small program change needs to be adjusted The entire software development has greatly improved the maintainability and expansion of the software.

(3) It is conducive to the simultaneous development of tasks, and it is easy to adapt to changes in requirements. The three-tier architecture technology has greatly solved the problem of software development, especially the problem of large-scale software development, allowing software development to achieve task synchronization. When developing software with two-layer technology, since there are only two endpoints, there is a programming sequence during software development. A team must be very clear about the entire software process and write programs for all links from beginning to end. The three-tier architecture technology divides the software into 4 levels, and there is little correlation between the layers, so the software can be divided into 4 different levels for synchronous development, so as to realize the synchronization of tasks, thereby greatly shortening the time of software development, and more Easily adapt to changing needs.

Disadvantages of software three-tier architecture technology

(1) The speed of reading data of the whole system is reduced. In the two-tier technology structure, most of the data reading is the result obtained through the client directly accessing the database, while the three-tier architecture technology must go through a complete process of 1/4 levels to get the final result, which virtually increases the intermediate link, thereby reducing the performance of the system.

(2) Sometimes it will lead to modification of the association level. Due to the logical relationship between the layers in the three-tier architecture technology, when a function of one of the layers is changed or added due to needs, it is likely to cause changes in the codes of other layers. For example: when a function is added to the presentation layer, in order to ensure the structural rationality of the design of each layer, it may be necessary to add corresponding codes in the corresponding business logic layer and data access layer, so as to achieve the final data consistency.

(3) The workload of overall code writing increases. Because the three-tier architecture technology increases the interface between layers, some codes that can be used directly have to be used separately, which virtually increases the workload of code writing.

(4) Increased development costs. The original software development as a whole must now be divided into layers of different functions, and the connection interface between layers needs to be considered, which virtually increases the process and workload of the entire software development, thereby increasing the cost of software development. cost.

Summarize

Generally speaking, in view of the increasingly large-scale and large-scale characteristics of today's software development, the three-tier architecture technology solves many problems that cannot be solved in the two-tier architecture technology, thus truly realizing the synchronization, maintainability and reliability of software development. Scalability is an important sign of progress in software development.

The above is the technical analysis of the three-tier architecture in software development introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. If you have software and hardware function development needs for smart electronic products, you can rest assured to entrust them to us. We have rich experience in customized development of electronic products, and can evaluate the development cycle and IC price as soon as possible, and can also calculate PCBA quotations. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, Bluetooth IC and module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth wifi development, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.