SAP : R/3 System Architecture & Components

R/3 System Architecture

R/3 system is a 3 tier architecture having
1. Presentation Server
2. Application Server
3. Database Server

• Presentation server 

The local desktop serves as the presentation server, which is nothing but SAP GUI where the user logon to the client and work from the local machine

• Application server

The server/computer on which the programs are run or executed is the application server. Application server receives the input from the presentation server and interpret the ABAP code and sends back the result to the presentation server

• Database server

1. The server/computer which receivers the request from the application server and interprets it and sends the request to RDBMS and collect the data requested from the RDBMS and sends back to the application server.
2. All objects such as source code/generated binary code, tables etc. are physically present in the RDBMS
3. R/3 is having the single database, which makes the operation of entire architecture faster and results in better performance

R/3 Architecture Components

List of R/3 components are as follows

• DISPATCHER
• WORK PROCESS
• DATABASE CONNECTIVITY

DISPATCHER:

This is a component which acts as an interface between Presentation Layer and the Application Server. It receives the request from the user from the Presentation Server/Layer and allocates work area for each request from the user.

WORK PROCESS:

This is a Component which allocates memory area for each request received from dispatcher on roll-in and roll-out basis. Once the request is process, the memory area is rolled out to allocate the next request from the dispatcher.

DATABASE CONNECTIVITY:

OPEN SQL - It receives the SAP R/3 specific OPEN SQL statement from the user and converts it into database specific NATIVE SQL format (Database used at the backend)

NATIVE SQL – It checks for the syntax in the request received and passes the request to the database through the gateway service