Question

Your customer wants to develop a system for stock information where dealers can access information about companies and can 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

A three-tier client-server architecture is recommended, separating presentation, application, and data responsibilities to support modularity and scalability.

Step-by-step solution

Outline the Requirements

In this step, we identify the key features required by the system: access to company information, evaluation of investment scenarios, and a flexible simulation system for different user experiences. This suggests a need for data processing, storage, retrieval, and multiple user interfaces.

Choose an Architecture Model

A three-tier client-server architecture is optimal for this system. It consists of a Presentation Tier (Client Side), an Application Tier (Server Side), and a Data Tier (Database Server). Each tier will manage different responsibilities, supporting separation of concerns and scalability.

Presentation Tier Design

The Presentation Tier is where the user interface functionalities reside. Dealers access the system via a web or desktop application, which communicates with the application server. This layer should manage user inputs and display results from the simulations.

Application Tier Design

Located on the server, the Application Tier processes business logic. It handles requests from the client side, simulates investment scenarios, manages authentication, and directs queries to the database. This tier ensures that each dealer's simulation needs, which vary, are processed accordingly.

Data Tier Design

The Data Tier manages data storage and retrieval. This tier is where all company information and historical stock data are stored. The Application Tier retrieves and updates this data as required, ensuring data consistency and enabling extensive, reliable simulations.

Justify the Model

A three-tier architecture is suitable as it separates concerns, enhancing modularity and scalability. The Presentation Tier handles user interactions, the Application Tier manages business logic and simulations, and the Data Tier ensures efficient data storage and access. This separation allows for easy maintenance and upgrades, accommodating future growth and varying dealer needs.

Key concepts

Three-Tier Architecture

In a three-tier architecture, the system is organized into three logical layers or "tiers." These tiers include the Presentation Tier, the Application Tier, and the Data Tier, each serving a distinct purpose. The main objective of this architecture is to separate concerns to better manage complexity.

The Presentation Tier acts as the user interface, providing interaction points for clients like dealers to access stock information. Next, the Application Tier serves as the engine behind the scenes, processing user inputs and executing business logic. It coordinates data requests and application responses. Lastly, the Data Tier is responsible for data storage and retrieval, containing all of the required company and stock data.

One of the greatest benefits of a three-tier architecture is modularity. By segmenting responsibilities across different layers, developers can independently update or scale each tier as needed without disrupting the others. This architecture is particularly advantageous for systems necessitating adaptability to varying loads and evolving needs.

System Design

System design involves planning and organizing the components of a system to meet specifications and user requirements. In the context of client-server architecture like our stock information system, system design focuses on understanding what the system must achieve and how to achieve it efficiently.

Key aspects in designing this system are determining the functionalities each tier must perform, specifying how the tiers will communicate, and ensuring scalability and security. For example, we design the Presentation Tier to cater to user conveniences. Meanwhile, the Application Tier is designed to efficiently handle diverse business logic, while the Data Tier focuses on secure and reliable data operations.

An effective system design will efficiently make use of resources, maintain high performance, and ensure responsiveness under load. This requires careful consideration of architecture choice and technologies employed.

Presentation Tier

The Presentation Tier is the topmost level of the three-tier architecture, focusing on user interaction. It handles everything the user directly engages with, whether via a web interface or a desktop application.

This tier's primary function is to capture user inputs and display the processed results, such as simulations of stock scenarios. User experience is paramount, so this layer is designed to be user-friendly and intuitive, providing users with ease of navigating through stock data and simulation tools.

Since the Presentation Tier communicates with the Application Tier, it is essential that it efficiently manage session states, inputs, and responses. This helps ensure a seamless and engaging user experience. Thrive for clean design and responsive interaction enhances how dealers use and benefit from the system.

Application Tier

The Application Tier is where all the magic happens. It is the core of the business logic and processes. This tier executes complex computations, such as simulations of investment scenarios, based on the inputs from the Presentation Tier.

It functions as the middleman between the user and the data. By handling requests, calculations, and logic necessary to process a stock dealer's strategy, the Application Tier ensures smooth and accurate operations. Moreover, it takes care of authentication and authorization, making sure secure access to sensitive financial data.

The Application Tier communicates with both the Presentation and Data Tiers. By sending queries and transactions to the Data Tier, it manages data retrieval and updates. On the other end, it sends processed outcomes back to the Presentation Tier, completing the information loop.

In this tier, scalability is crucial. Because it may need to handle ever-increasing amounts of processing as the system gains more users or as data complexity grows. This tier must remain robust, efficient, and agile to accommodate expanding business needs.