Architecture - (Client|Server) - (Multi)Tier Architecture


On a application level, the two most common architectures are:

  • client/server
  • and multitier.

As internet computing becomes more prevalent in computing environments, many database management systems are moving to a multitier environment.

Type of Architecture


An system can easily take advantage of distributed processing by using its client/server architecture. In this architecture, the database system has two parts: a front-end or a client, and a back-end or a server.

The Client

The client is a database application that initiates a request for an operation to be performed on the database server. It requests, processes, and presents data managed by the server. The client workstation can be optimized for its job. For example, the client might not need large disk capacity, or it might benefit from graphic capabilities. Often, the client runs on a different computer than the database server. Many clients can simultaneously run against one server.

The Server

The server runs Oracle Database software and handles the functions required for concurrent, shared data access. The server receives and processes requests that originate from client applications. The computer that manages the server can be optimized for its duties. For example, the server computer can have large disk capacity and fast processors.


Application Servers

A traditional multitier architecture has the following components:

  • A client or initiator process that starts an operation
  • One or more application servers that perform parts of the operation. An application server contains a large part of the application logic, provides access to the data for the client, and performs some query processing, thus removing some of the load from the database server. The application server can serve as an interface between clients and multiple database servers and can provide an additional level of security.
  • An end server or database server that stores most of the data used in the operation

This architecture enables use of an application server to do the following:

  • Validate the credentials of a client, such as a Web browser
  • Connect to an Oracle Database server
  • Perform the requested operation on behalf of the client

If proxy authentication is being used, then the identity of the client is maintained throughout all tiers of the connection.

Service-Oriented Architecture

Service-oriented architecture (SOA) is a multitier architecture in which application functionality is encapsulated in services. SOA services are usually implemented as Web services. Web services can be accessed with the HTTP protocol and are based on a set of XML-based open standards, such as WSDL and SOAP.

Powered by ComboStrap