SAP Follows R/3 architecture. “R” Stands for “Real-time data processing,” and “3” stands for “3-tier” that includes a database, application server, and client. Whenever any data user enters any document or information, it will process immediately in SAP, and the effect of this document can be seen in real-time. The traditional computing i.e., client-server architecture, is replaced with three tiers in SAP, and it was launched in 1992 after two decades of SAP R2 architecture.
3 Tier Architecture can be divided into three main divisions as below:
1.1 Database Layer
Every software has a database system as a base which is stored in the server known as a database server. All the information and data are stored under the database layer. Example of the database is
Oracle
Informix
DB2
MySQL
Max DB
Hana Db
1.2 Application Layer
Software where applications are stored, and some processing takes place. Some of the contents of the application layer are work processes, dispatcher, gateway service, message server, kernel, and shared memory. In this layer, application programs are executed.
It mainly consists of two components:
1. Processes – Dialog for interactions between user and system, Spool for printer activities, Background for long-duration activities, Update for updating databases, Enqueue for following a queue while updating a database.
2. Services - Message to balance load among application servers and Gateway as a communication channel between two SAP systems or an SAP system and non-SAP system.
1.3 Presentation Layer
This layer allows access to the end-users or clients. SAP GUI comes under the presentation layer. This layer is responsible for the presentation of data for users and receiving user entries. For example, if our application and database layer is in India, using SAP GUI, the end-user can access all the reports sitting anywhere in the world.
This layer is also known as the client layer, as it is mainly for user interaction that is done through the SAP GUI. It resides in the user machine as a software. The example of this graphical interface can be desktop software, mobile devices software, and it also can be used in laptops.
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