SAP System Architecture & Landscape: A Comprehensive Guide

Learn about SAP System Architecture and Landscape, including its key layers (Presentation, Application, and Database) and system environments (Development, Quality, and Production). Understand how SAP systems function to support enterprise operations efficiently.

• Index

1. SAP Architecture:

1. System Architecture:

• Presentation Layer.

• Application Layer.

• Database Layer.

2. System Landscape:

• Development System.

• Quality System.

• Production System.

1. SAP Architecture:

1. System Architecture:

1. Presentation Layer:

- The presentation layer consists of the user interface, which runs on a client machine that uses a standard graphical user interface (GUI). The user interface can be a web browser or propriety software like SAP GUI. Because the presentation layer can be developed independently depending on the requirements and system configuration, it can support various devices (PCs, smartphones, etc.) and operating system environments.

- The GUI communicates with the application layer by taking user inputs, sending requests to the application server, and displaying the results received from the application server. For example, when you open a website in your web browser, you are requesting a resource from the web server. The web server responds to your request, and the browser presents the result in a user-friendly way.

- There are two options for the presentation layer: (SAP GUI - web browser).

2. Application Layer:

- The application layer is where all the major work is done by ABAP programs.

- This is the software layer that hosts various modules of business functions and executes program code.

- It can consist of one or multiple application servers and a messaging server, which is responsible
for communication within the layer. 

- When you run an application, the execution takes place in the application layer.

- The application layer can communicate with the database to process the data requested by the user.

- The application layer includes one or more application servers and a message server.

- The message server is responsible for communication between the application servers.

- The application server interprets ABAP programs by providing the runtime environment to execute ABAP code.

- Internet Communication Manager (ICM):

• The ICM enables the application server to communicate with the outside world using web protocols
  like HTTP, HTTPS, or SMTP.

• The ICM web-enables the application server, this allows users to use a web browser to make requests
  to the application server, as opposed to using SAP’s proprietary GUI. 

• ICM runs as a separate process, started and monitored by the ABAP Dispatcher.

• With ICM, the application server can process requests from the Internet, such as Web Dynpro-based applications. 

- ABAP Dispatcher:

• Each application server has a dispatcher. 

• The role of the dispatcher is to assign requests to work processes.

• A user makes a request, the request is sent to the dispatcher, and the dispatcher assigns the request to a freely available work process, Once the request is assigned to the work process, the work process executes the request and sends back the result, The work process then becomes free, ready to take up another request. 

• When a user logs in to an SAP system, the logon request goes to the message server, which performs
  load balancing and connects the user to the dispatcher of an instance with the least.

- Work Processes (WP):

• User requests are processed through work processes. 

• There may exists multiple work processes per application server instance.

• When a user makes a request, the request is sent to the ABAP Dispatcher, the ABAP Dispatcher, in turn, assigns
  the request to the available work process for processing, Once the work process completes the request, it sends back
  the result, and the work process becomes free again to take a new request.

3. Database Layer:

- The database layer is where all the persistent data is stored.

- The database is typically managed by a relational database management system (RDBMS).

- The RDBMS provides a declarative method to maintain data and queries, and the system takes
care of describing the structures for storing the data.

- SAP supports various database systems, like SAP HANA, Oracle, MSSQL, M0axDB, and IBM DB/2.

2. System Landscape:

 

- When implementing an SAP system, organizations typically implement at least three separate systems:
one for development, one for quality assurance/testing, and one for a production environment.

- Each of these SAP systems have three layers, the presentation layer, application layer, and database layer.