Atchitecture Released

3-Tier Architecture

Three-Tier is a client–server architecture in which the user interface, functional process logic, computer data storage and data access are developed and maintained as independent modules, most often on separate platforms. It was developed by John J. Donovan in Open Environment Corporation, a tools company he founded in Cambridge, MA.

The three-tier model is software architecture and a software design pattern.

Apart from the usual advantages of modular software with well-defined interfaces, the three-tier architecture is intended to allow any of the three tiers to be upgraded or replaced independently as requirements or technology change. For example, a change of operating system in the presentation tier would only affect the user interface code.

Typically, the user interface runs on a desktop PC or workstation and uses a standard graphical user interface, functional process logic may consist of one or more separate modules running on a workstation or application server, and an RDBMS on a database server or mainframe contains the computer data storage logic. The middle tier may be multi-tiered itself.

Data Access Tier

This tier consists of database servers. Here information is stored and retrieved. This tier keeps data neutral and independent from application servers or business logic. Giving data its own tier also improves scalability and performance.

Business Logic Tier

The business logic tier is pulled out from the presentation tier and, as its own tier, it controls an application’s functionality by performing detailed processing.

User Interface Tier

This is the topmost level of the application. The user interface tier displays information related to such services as browsing merchandise, purchasing, and shopping cart contents. It communicates with other tiers by outputting results to the browser/client tier and all other tiers in the network.

MVC Architecture

Model–View–Controller is a software architecture, currently considered an architectural pattern used in software engineering. The pattern isolates "domain logic" from input and presentation, permitting independent development, testing and maintenance of each.

Model

The model is used to manage information and notify observers when that information changes. The model is the domain-specific representation of the data upon which the application operates. Domain logic adds meaning to raw data. When a model changes its state, it notifies its associated views so they can be refreshed.

View

The view renders the model into a form suitable for interaction, typically a user interface element. Multiple views can exist for a single model for different purposes. A viewport typically has a one to one correspondence with a display surface and knows how to render to it.

Controller

The controller receives input and initiates a response by making calls on model objects. A controller accepts input from the user and instructs the model and viewport to perform actions based on that input.

Client Server Architecture

The client–server model of computing is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. Often clients and servers communicate over a computer network on separate hardware, but both client and server may reside in the same system. A server machine is a host that is running one or more server programs which share their resources with clients. A client does not share any of its resources, but requests a server's content or service function. Clients therefore initiate communication sessions with servers which await incoming requests.

Database Server

A database server is a computer program that provides database services to other computer programs or computers, as defined by the client–server model. The term may also refer to a computer dedicated to running such a program. Database management systems frequently provide database server functionality, and some DBMSs rely exclusively on the client–server model for database access.

Application Server

An application server is a software framework dedicated to the efficient execution of procedures for supporting the construction of applications. The term was originally used when discussing early client–server systems and servers that run SQL services and middleware servers to differentiate them from file servers.

Client

A client is an application or system that accesses a remote service on another computer system, known as a server, by way of a network. The term was first applied to devices that were not capable of running their own stand-alone programs, but could interact with remote computers via a network. These dumb terminals were clients of the time-sharing mainframe computer.