Tiered Architecture in Distributed System

Tiered architecture, or multitiered architecture, is a design approach used in software development to separate functionalities into distinct layers or tiers. Each tier has a specific role, allowing for better organization, scalability, and system maintainability. Here’s an overview of the common tiers in a multitiered architecture:

1. Presentation Tier:

The presentation tier, also known as the user interface tier, is responsible for presenting information to users and accepting user inputs. Its main purpose is to handle user interactions and display data in a human-readable format. This tier provides the interface through which users interact with the application.

Components:

• User Interfaces: This includes web browsers, mobile applications, desktop applications, or any other means through which users interact with the system.
• UI Components: Components such as forms, buttons, menus, and other graphical elements that enable user interaction.
• Presentation Logic: Code responsible for controlling the behavior and appearance of the user interface.

Example: Consider an e-commerce website. The presentation tier would include the web pages users see when browsing products, adding items to their cart, and completing their purchases. It encompasses the visual design, layout, and interactive elements like buttons and forms.

2. Application Tier:

The application tier, also referred to as the business logic tier or middle tier, contains the core logic and functionality of the application. It processes user requests, implements business rules, performs computations, and coordinates the application’s overall behavior. This tier acts as an intermediary between the presentation tier and the data tier.

Components:

• Application Servers: These servers execute the application’s code and handle business logic tasks.
• APIs (Application Programming Interfaces): Interfaces that allow different parts of the application to communicate with each other or with external systems.
• Business Logic: Code responsible for implementing the application’s rules, workflows, and algorithms.
• Middleware: Software components that facilitate communication and integration between different parts of the system.

Example: In an online banking system, the application tier would manage tasks such as validating user credentials, processing transactions, checking account balances, and generating reports. It ensures that business rules are enforced, transactions are secure, and data integrity is maintained.

3. Data Tier:

The data tier, also known as the persistence tier or backend tier, is responsible for managing data storage, retrieval, and manipulation. It stores the application’s data in a structured format, making it accessible to other tiers as needed. This tier ensures data integrity, security, and efficiency in data operations.

Components:

• Databases: Systems such as relational databases, NoSQL databases, or file systems used to store and organize data.
• Data Access Layer: Components responsible for interacting with the database, executing queries, and handling data retrieval and manipulation.
• Data Models: Structures that represent the organization and relationships of the data stored in the database.

Example: In a social media platform, the data tier would manage user profiles, posts, comments, and other content. It would include databases to store user information, relationships between users, posts, comments, media files, and any other relevant data. The data tier ensures that data is stored securely, retrieved efficiently, and remains consistent across the application.

Multitiered Architectures in Distributed Systems explains how complex computer systems are organized into different layers or tiers to improve performance and manageability. Each tier has a specific role, such as handling user interactions, processing data, or storing information.

• By dividing tasks among these tiers, systems can run more efficiently, be more secure, and handle more users at once.
• This architecture is widely used in modern applications like web services, where front-end interfaces, business logic, and databases are separated to enhance functionality and scalability.