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Architecture of SAP NetWeaver Application Server ABAPLocate this document in the navigation structure

SAP NetWeaver Application Server for ABAP provides both the runtime environment and the development environment for all ABAP programs.

The design of SAP NetWeaver Application Server is aimed at providing an exceptionally high level of robustness and supportability for the applications running on it. The architecture of SAP NetWeaver Application Server ABAP and basic terminology are explained below. For details, see the component-specific documentation.

Instances of SAP NetWeaver Application Server ABAP

An SAP NetWeaver Application Server ABAP system has various instances. An instance is an administrative unit containing various components of an SAP system. The components of an instance are parameterized in a shared instance profile. Each instance is identified by a system ID and an instance number. A distinction is made between application server instances and ABAP SAP Central Services instances (ASCS instances).

There can be any number of application server instances in an SAP NetWeaver application server. The instances process incoming user requests. An ABAP application server instance contains one Internet Communication Manager, one ABAP dispatcher, one gateway, one SAP start service, and any number of work processes.

As well as multiple application server instances, there is one special instance that contains the message server, the enqueue server, and a separate start service - the ASCS instance (ABAP System Central Services instance). The ASCS instance cannot process any dialog requests - it is used to manage locks, exchange messages, and balance workload in the SAP system.

Overview of the Components of SAP NetWeaver Application Server ABAP

SAP NetWeaver Application Server ABAP is made up of the following components:

  • Internet Communication Manager (ICM)

  • ABAP dispatcher

  • Task handler

  • Any number of work processes (dialog, update, print, background, and so on)

  • RFC Gateway

  • Standalone enqueue server

  • SAP Message Server

The system can be enhanced with the following optional components:

  • SAP Web Dispatcher

  • SAProuter

The following figure shows the components of an ABAP system. For a better overview, series lines have not been used. Incoming requests are handled directly by the Internet Communication Manager or SAP Web Dispatcher, ABAP Dispatcher, or Gateway, depending on the request type. There is one database for each ABAP system.