ICT 2.3

Understanding Modern Application Architecture

Overview of Application Architecture

• Modern system architecture relies on interconnected networks for the free flow of information, essential for organizations to conduct business and achieve goals.

• Application architecture focuses on data flow and processing within an organization, addressing fundamental business needs and being a primary consideration in IT system design.

• IT systems are complex with multiple layers; their analysis, design, and implementation require collaboration among various analysts and designers.

Types of System Architectures

• Different application architectures help organizations meet requirements for distributed data; examples include client-server, web-based, cloud, and peer-to-peer computing.

• The client-server model is the most commonly used due to its simplicity; it involves a client program requesting services from a corresponding server program.

Client-Server Architecture

• In a two-tier architecture (the simplest form), one client requests information from one server which processes the request and sends back the response.

• A typical example is a web browser (client) sending requests to a web server for HTML files that are then displayed graphically.

Multi-Tier Architectures

• Organizations often use multiple servers; dedicated servers handle single services while shared servers run multiple services simultaneously.

• Three-tier architecture consists of three computers: one client and two servers. One server retrieves data from another before responding to the client.

Cloud Computing

• Cloud computing distributes services across many platforms rather than relying on local servers; it includes off-site storage or processing facilities.

• Common types of cloud computing services include Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS).

Peer-to-Peer Computing

• In peer-to-peer systems, devices communicate directly without central control; each device acts as both server and client in sharing information.

• Disadvantages include challenges in maintaining updated lists of hosts/services and network security risks such as virus propagation.

Hybrid Models

• Various architectures can be combined into hybrid models; for instance, clients may connect to central servers initially before communicating peer-to-peer.

Summary of Key Concepts

• Application architecture encompasses systems managing data flow within organizations. Key types discussed include client-server, cloud computing, and peer-to-peer models. Each has unique characteristics suited for different organizational needs.