The Four Tiers of InfoSphere Information Server (ISS)
Infosphere Information Server (IIS) is organized into these four tiers:
The client tier is a logical tier which consists of the client programs and consoles that are used for development, administration, and other tasks. The Infosphere information server consoles included in the client tier are, actually, web based components, while other components, such as Datastage Designer, are windows client based applications.
The services tier consists of the application server (IBM WebSphere), common services, and product services for the suite and product modules. The services tier provides common services, such as security, and services which are specific to certain product modules. On the services tier, IBM WebSphere® Application Server hosts the services and the InfoSphere Information Server applications which are Web-based.
The engine tier is the logical group of engine components, communication agents, and so on. The engine runs jobs and other tasks for product components and modules, such as, DataStage and Information Analyzer.
The repository tier consists of the IBM InfoSphere Information Server metadata repository and, if installed, other data stores to support other product modules. The metadata repository contains the shared metadata, data, and configuration information for InfoSphere® Information Server product components and modules. The other data stores store extended data for use by the product modules they support, such as the operations database, which is a data store that is used by the engine operations console.