The Oracle E-Business Suite Architecture is a framework for multi-tiered, distributed computing that supports Oracle E-Business Suite products. In this model, various servers or services are distributed among three levels, or tiers.
A server (or services) is a process or group of processes that runs on a single machine and provides a particular functionality. For example, Web services process HTTP requests, and Forms services process requests for activities related to Oracle Forms. The Concurrent Processing server supports data-intensive programs that run in the background.
A tier is a logical grouping of services, potentially spread across more than one physical machine.
The three-tier architecture that comprises an Oracle E-Business Suite installation is made up of
- the database tier, which supports and manages the Oracle database.
- theapplication tier, which supports and manages the various Oracle E-Business Suite components, and is sometimes known as the middle tier; and
- the desktop tier, which provides the user interface via an add-on component to a standard web browser.
The Database Tier
The database tier contains the Oracle database server that stores and manages all the data maintained by Oracle E-Business Suite. This includes the various types of file in which the tables, indexes, and other database objects for your system physically reside, as well as the database executables. The database also stores the Oracle E-Business Suite online help information.
The database server communicates with the services and servers on the application tier, which mediate the communications between the database and the clients: there is no direct communication between the database and clients.
The Application TierThe application tier has a dual role: hosting the various servers and service groups that process the business logic, and managing communication between the desktop tier and the database tier. This tier is sometimes referred to as the middle tier.
Three servers or service groups comprise the basic application tier for Oracle E-Business Suite:
Concurrent Processing server
The Desktop TierThe client interface is provided through HTML for HTML-based applications, and via a Java applet in a Web browser for the traditional Forms-based applications.
You log in via the Oracle E-Business Suite Home Page on a desktop client web browser. The Home Page provides a single point of access to HTML-based applications, Forms-based applications, and Business Intelligence applications.
Once successfully logged in via the E-Business Suite Home Page, you are not prompted for your user name and password again, even if you navigate to other tools and products. Oracle E-Business Suite also retains preferences as you navigate through the system. For example, if you registered in the Home Page that German is your preferred language, this preference carries over whether you access Forms-based or HTML-based applications.
FORM-based Oracle E-Business Suite interface
A machine may be referred to as a node, particularly in the context of a group of computers that work closely together in a cluster. Each tier may consist of one or more nodes, and each node can potentially accommodate more than one tier. For example, the database can reside on the same node as one or more application tier components. Note, however, that a node is also a software concept, referring to a logical grouping of servers.
Centralizing the Oracle E-Business Suite software on the application tier eliminates the need to install and maintain application software on each desktop client PC, and also enables Oracle E-Business Suite to scale well with an increasing load. Extending this concept further, one of the key benefits of using the Shared Application Tier File System model (originally Shared APPL_TOP) is the need to maintain only a single copy of the relevant Oracle E-Business Suite code, instead of a copy for every application tier machine.
On the database tier, there is increasing use of Oracle Real Application Clusters (Oracle RAC) , where multiple nodes support a single database instance to give greater availability and scalability.
The connection between the application tier and the desktop tier can operate successfully over a Wide Area Network (WAN). This is because the desktop and application tiers exchange a minimum amount of information, for example only field values that have changed. In a global operation with users at diverse locations, requiring less network traffic reduces telecommunications costs and improves response times.