SAP architecture provides a distributed system which requires a common environment provided by Netweaver. The SAP Web Application Server can run on Netweaver and the architecture is divided in three layers which include the presentation layer, the application layer/business layer and the database layer.
Presentation layer
The layer provides the user with an interface from where the user can interact with applications. The presentation layer includes a Graphical User Interface, which is used to execute application logic and to utilize other interfaces.
The presentation server (sapgui.exe) is installed on workstation and it displays the menus of the solution. The interface takes in user input to run processes. The request from user interface is send to application server to be processed, which sends the results back to user interface to display.
Application layer
It contains executables which are interpreted by the server and when the application server starts, these executables start running, and when the application server stops - the executable shut down. The startup processes can be defined in the application server profile and the characteristics of processes such as number of processes, their types, memory usage and length of time can be defined for each process.
Database layer
The database server runs the requests and sends to the RDBMS. The results are sent back to the application server.
Multi layer architecture
In case of distributed architecture, distribution works over a number of layers which makes the system scalable and the load on the server is distributed on various layers.
The functioning of the layers can be moved to various servers and it is made possible due to the participation and communication of various servers. In case of one level system architecture the processing can be done on one server and for two levels configuration special servers are used for implementation. The presentation server allows the end users to access the server through the workstation. Separate servers are used in case of three level configuration and the three layer including application layer, the presentation layer and the database run on different servers.
In case of multi layer architecture, the software provides a high level of flexibility to run on various different types of hardware or OS environments.
For example - mySAP Business Suite can run on various different OS platforms because the architecture allows the solution to support many different types of OS and hardware platforms. The application logic can also run on different operating systems and hardware platforms and no customization is required to run the systems on different OS. The environment allows it to be independent of operating system and the environment can be created using SAP web AS or SAP Basis.
Internet enabled architecture
SAP Web Application Server helps in processing HTTP requests using the Internet Communication Management which can communicate to internet as a client and a server.
As compared to the initial SAP architecture, the new SAP version SAP Basis has the feature of web server for internet access. SAP Basis can provide runtime to run all the SAP applications and it also ensures that the application can be integrated to the environment.
