1).SAP XI ... Introduction

SAP Exchange Infrastructure (SAP XI) is SAP's enterprise application integration (EAI) software, a component of the NetWeaver product group used to facilitate the exchange of information among a company's internal software and systems and those of external parties. Like other NetWeaver components, SAP XI is compatible with software products of other companies.SAP calls XI an integration broker because it mediates between entities with varying requirements in terms of connectivity, format, and protocols. According to SAP, XI reduces the TCO by providing a common repository for interfaces. The central component of SAP XI is the SAP Integration Server, which facilitates interaction between diverse operating systems and applications across internal and external networked computer systems.XI is built upon the SAP Web Application Server.

Purpose

SAP Exchange Infrastructure (SAP XI) enables you to implement cross-system processes. It enables you to connect systems from different vendors (non-SAP and SAP) in different versions and implemented in different programming languages (Java, ABAP, and so on) to each other. SAP Exchange Infrastructure is based on an open architecture, uses open standards (in particular those from the XML and Java environments) and offers those services that are essential in a heterogeneous and complex system landscape:

● Modeling and design of messages, transformations, and cross-component integration processes
● Configuration options for managing collaborative processes and message flow
● Runtime for message and process management
● Adapter Engine for integrating heterogeneous system components
● Central monitoring for monitoring message flow and processes
SAP XI supports internal company scenarios and cross-company scenarios

Integration

The following graphic is a simple overview showing how SAP XI is positioned within SAP NetWeaver. The important components and concepts of SAP XI are shown on the right-hand side. These are described in more detail in the overview section

Features

SAP XI is based on general standards so as to enable external systems to be integrated. At the center of the infrastructure is an XML-based communication that uses HTTP (Hyper Text Transfer Protocol). The application-specific contents are transferred in messages in user-defined XML (eXtensible Markup Language) schema from the sender to the receiver using the Integration Server.

Senders and receivers that exchange messages using the Integration Server are separated from one another. This separation makes it easier to connect systems that are technologically different. Every system that can exchange messages with the Integration Server can also exchange messages with all other systems that are connected to the Integration Server. SAP XI supports the following methods of communication with the Integration Server:

● Direct communication using proxies, which you generate in the application systems using a description in WSDL (Web Service Description Language).
● Communication using adapters. In this case, you create interfaces for message exchange in the application system, or use existing interfaces.

Simple message processing on the Integration Server is stateless. This means that the Integration Server does not know of any connections between various messages. Cross-component integration processes, on the other hand, describe related processes, which can use the knowledge about messages that have already been processed to further control the process (for example, waiting for the corresponding response for a message in order to start further actions). You can use SAP XI to model, change, and manage these cross-component integration processes centrally. These processes are executed on the Integration Server and are included in message processing by configuration.

As with cross-component integration processes, you save the entire integration knowledge of a collaborative process centrally in SAP XI: Objects at design time in the Integration Repository and objects at configuration time in the Integration Directory. In this way, SAP Exchange Infrastructure follows the principle of shared collaboration knowledge: You no longer need to search for information about a collaborative process in each of the systems involved, but can call this information centrally instead. This procedure considerably reduces the costs for the development and maintenance of the shared applications.