Question

Your customer wants to develop a system for stock information where dealers can access information about companies and evaluate various investment scenarios using a simulation system. Each dealer uses this simulation in a different way, according to his or her experience and the type of stocks in question. Suggest a client-server architecture for this system that shows where functionality is located. Justify the client-server system model that you have chosen.

Short answer

Use a three-tier client-server architecture, distributing presentation, business logic, and data management across client and server.

Step-by-step solution

Identify Client and Server Responsibilities

In a client-server architecture, it is essential to define what functionalities are managed by the client and which by the server. In this scenario, the server will handle data storage, updates, and processing, while the client will focus on user interface tasks and sending requests to the server.

Decide on the Specific Architecture Model

Considering the needs for real-time data and reliable processing, a three-tier architecture is appropriate. This model consists of a presentation layer (client-side), application logic layer, and data storage layer (server-side).

Define Presentation Layer Details

The presentation layer includes the user interface, which can be a web, desktop, or mobile application. This layer allows dealers to interact with the system and request data from the server. It's crucial for this layer to facilitate seamless user experiences.

Define Application Logic Layer

The middle layer (business logic layer) processes user requests, handles simulations, and updates stock information. This centralized processing ensures consistency and reliability in handling various simulation scenarios for different users.

Define Data Management Layer

The data layer is responsible for storing company stock data, user profiles, and simulation history. It must be robust and secure, ensuring data integrity and fast retrieval times to support real-time operations.

Justify the Chosen Model

The three-tier architecture is justified because it provides scalability for an increasing number of dealers, enhances data security and integrity, and allows for independent updating of each layer without affecting others, thus improving maintainability.

Key concepts

Three-Tier Architecture

Three-tier architecture is a model for client-server systems that organizes actions into three distinct layers. In this setup:

• The presentation layer handles user interaction
• The application logic layer manages the processing and business logic
• The data management layer deals with storage and retrieval

This structure enhances performance and allows separate layers to be modified independently without affecting the entire system.
Three-tier architecture is particularly beneficial for systems that require scalability and flexibility, such as platforms with increasing user demand.
By distributing responsibilities among three layers, the system becomes more manageable and adaptable, ensuring that users have a smooth and efficient experience.

Presentation Layer

The presentation layer is the user's gateway to the system. It is responsible for how the user interacts with the software, providing the visual interface and facilitating smooth communication. In modern systems, this could be a web page, a mobile app, or a desktop application.
Designing an intuitive presentation layer is key, as it directly affects user satisfaction. It must be user-friendly, fast, and reliable, ensuring that the user's experience is seamless as they navigate through features and requests.
Additionally, the presentation layer sends requests to the application logic layer and receives data to present to the user, effectively acting as a communicator between the user and the system's deeper functionalities.

Application Logic Layer

The application logic layer is the powerhouse of a system. It processes user requests coming from the presentation layer, runs the necessary calculations or simulations, and prepares data to be forwarded back.

• Manages complex computations
• Ensures that rules and processes are consistently applied
• Protects and handles business logics

For instance, in a stock platform, this layer would handle simulations of investment scenarios, applying algorithms to predict trends based on user inputs.
The independence of this layer means it can be updated to improve performance or integrate new functionalities without impacting the other tiers.

Data Management Layer

The data management layer is like a library, storing all the necessary information that the application needs to function. It holds company stock data, user information, and logs like simulation histories.
Security is crucial in this layer, as it involves sensitive information, and must ensure data integrity and protection against unauthorized access. Efficiency is also key, allowing fast data retrieval and support for real-time operations.
This layer communicates closely with the application logic layer to store and provide the data needed for processing, subsequently helping to maintain overall system reliability and performance.