SAP PI - Netweaver PI Architecture

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SAP PI architecture consists of multiple components which are used at design time, configuration time and runtime. In SAP PI, the sender system is known as the source and the receiver is called the target system and the architecture is known as Hub and Spoke structure. The Spoke is used to connect with external systems and Hub is used to exchange messages.

A SAP PI system is divided into the following components −

• Integration Server
• Integration Builder
• System Landscape Directory SLD
• Configuration and Monitoring

Runtime Workbench

This is a tool used to provide central monitoring of PI components and messages.

Integration Server

This is one of the key components of the SAP PI system and is used for processing of messages.

It consists of the following three engines −

• Business Process Engine
• Integration Engine
• Central Advanced Adapter Engine AAE

Business Process Engine

This engine is used for message correlation and deals with the processing of messages in ccBPM.

Integration Engine

This engine is used for routing and mapping and provides central integration server services. If the source structure is different from the target structure, the integration engine calls mapping runtime as shown in the illustration below wherein, the source structure is converted to target structure.

A mapping runtime is based on Java Stack as mentioned under the SAP PI platform topic.

A message can be of the following two types −

• Synchronous message is defined as message contains both the request-response part

• Asynchronous message is defined as message contains either request or the response part only

In SAP PI, a message is represented by an interface. An Interface contains the structure of the message in XML format and the direction.

Central Advanced Adapter Engine (AAE)

As Integration Engine handles messages in XML and SOAP protocol, if the business system doesn’t contain data in a specific format, adapters are used to convert the messages specific protocol and message format required by the Integration Engine.

In SAP PI architecture, you can consider Adapter Engine as Spoke and Integration Engine as HUB to connect to external systems.

In SAP PI older releases dual stack system, most of the adapters were part of Java stack and only two adapters were part of ABAP stack.

Java Stack Adapters

The following adapters run on Java Stack −

RFC adapter, SAP Business Connector adapter, file/FTP adapter, JDBC adapter, JMS adapter, SOAP adapter, Marketplace Adapter, Mail adapter, RNIF adapter, CIDX adapter

ABAP Stack Adapters

The following adapters run on ABAP Stack −

Sr.No	ABAP Stack Adapter & Description
1	IDOC and HTTP Adapter In the latest releases when SAP PI moved to the single stack system, these two adapters also moved to the Java stack and the new engine thus formed is known as Advanced Adapter Engine AAE.
2	Service Repository Services Registry is a UDDI complaint registry, listing available Web Service Definitions (based on WSDL), extended with a classification system.
3	Enterprise Service Repository This is used to store design time repository objects like mapping, interfaces and process definitions in the PI system.
4	System Landscape Directory (SLD) This contains the information about landscape and software component versions. A SAP system can be configured to register under SLD.
5	Integration Repository This is used to configure the scenarios in PI system for exchange of messages between different systems.