N-Tier Architecture

UNIT - 7: N-Tier Architecture Structure: 7.0 Learning Objectives. 7.1 Introduction. 7.2 N-tier Architecture. 7.3 Summary. 7.4 Glossary. 7.5 References. 7.0 Learning Objectives: After studying this unit, you will be able to: Define what is N-Tier Architecture. 7.1 Introduction: N-tier architecture is a client-server architecture concept in software engineering where the presentation, processing and data management functions are both logically and physically separated. These functions are each running on a separate machine or separate clusters so that each is able to provide the services at top capacity since there is no resource sharing. This separation makes managing each separately easier since doing work on one does not affect the others, isolating any problems that might occur. N-tier architecture is also known as multi-tier architecture.

7.2 N-TIER ARCHITECTURE N-tier architecture usually divides an application into three layers: • Presentation Layer: UI of software. • Application Layer: Logic of software. • Database Layer: Database Management of software. It is the physical separation of the different parts of the application as opposed to the usually conceptual or logical separation of the elements in the model-view-controller (MVC) framework. Another difference from the MVC framework is that n-tier layers are connected linearly, meaning all communication must go through the middle layer, which is the logic tier. In MVC, there is no actual middle layer because the interaction is triangular; the control layer has access to both the view and model layers and the model also accesses the view; the controller also creates a model based on the requirements and pushes this to the view. However, they are not mutually exclusive, as the MVC framework can be used in conjunction with the n-tier architecture, with the n-tier being the overall architecture used and MVC used as the framework for the presentation tier.

Types of N Tier architecture: Single Tier or 1-Tier Architecture. It is the simplest one as it is equivalent to running the application on the personal computer. All of the required components for an application to run are on a single application or server. Presentation layer, Business logic layer, and data layer are all located on a single machine. 2-Tier Architecture. It is like Client-Server architecture, where communication takes place between client and server. In this type of software architecture, the presentation layer or user interface layer runs on the client side while dataset layer gets executed and stored on server side. There is no Business logic layer or immediate layer in between client and server. 3-tier Architecture and It’s Layers.

• Presentation tier: The top-most level of the application is the user interface. The main function of the interface is to translate tasks and results to something the user can understand. Logic tier: This layer coordinates the application processes commands, makes logical decisions and performs calculations. It moves and processes data between the two surrounding layers. • Data tier: Information is stored and retrieved from a database or a file system. The information is then passed back to the logic tier for processing and then eventually back to the user. There are several benefits to using n-tier architecture for your software. Secure: You can secure each of the three tiers separately using different methods. Easy to manage: You can manage each tier separately, adding or modifying each tier without affecting the other tiers. Scalable: If you need to add more resources, you can do it per tier, without affecting the other tiers. Flexible: Apart from isolated scalability, you can also expand each tier in any manner that your requirements dictate. In short, with n-tier architecture, you can adopt new technologies and add more components without having to rewrite the entire application or redesigning your whole software, thus making it easier to scale or maintain. Meanwhile, in terms of security, you can store sensitive or confidential information in the logic tier, keeping it away from the presentation tier, thus making it more secure. Other benefits include: More efficient development: N-tier architecture is very friendly for development, as different teams may work on each tier. This way, you can be sure the design and presentation professionals work on the presentation tier and the database experts work on the data tier.

Easy to add new features: If you want to introduce a new feature, you can add it to the appropriate tier without affecting the other tiers. Easy to reuse: Because the application is divided into independent tiers, you can easily reuse each tier for other software projects. For instance, if you want to use the same program, but for a different data set, you can just replicate the logic and presentation tiers and then create a new data tier. 7.3 Summary Today we have learnt: Brief Knowledge about N-tier Architecture 7.4 Glossary Framework: Tool that provides ready-made components or solutions that are customized in order to speed up development. 7.5 References https://stackoverflow.com/questions/312187/what-is-n-tier-architecture https://www.guru99.com/n-tier-architecture-system-concepts-tips.html