Chapter 1   Basic Connector Concepts


This chapter describes the three-tiered, web-based computing model. It also summarizes the main functions of the enterprise SAP which enables the communication between the web-based end user and a remote Enterprise Information System data source.

The chapter discusses the following:

• Three-Tier Application Model

• About the UIF

• Architecture of the SAP R/3 Connector

• Enterprise Connector Tools for SAP R/3

Three-Tier Application Model

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iPlanet Enterprise Connectors are an integral part of the middleware between enterprise data sources and the clients that access those data sources. The machine and software involved are divided into three tiers:

• a client tier; the user interface. Requests for data originate here, represented by web browsers or rich clients (such as a Java applet).

• a server tier represented by a web server such as iPlanet Web Server Enterprise Edition and an application server which runs the business code such as iPlanet Application Server.

• a data tier, represented by relational databases or other backend data sources such as Oracle or SAP R/3.

The connectors serve as an essential link allowing the server tier to communicate with the data tier, as shown in the following illustration.

Figure 1-1    Three-tier web-based computer model

In addition to the enterprise connector, communication between the application server and the backend EIS is facilitated by the Unified Integrated Framework (UIF) of application programming interfaces (API). This layer of functionality resides as an added layer to the iPlanet Application Server and enables data communication between diverse backend Enterprise Information Systems (EIS) to be implemented in a seamless and uniform manner.

About the UIF

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The iPlanet Application Server Enterprise Connector for SAP R/3 uses the UIF module of the iPlanet Application Server to communicate with SAP R/3 and a number of other EIS data sources. PeopleSoft, CICS, and Tuxedo are also supported by the UIF set of APIs with more planned for the future, as shown in the following illustration.

Figure 1-2    The Unified Integration Framework

The UIF is a toolkit that enables development of server extensions that integrate with new, web-based enterprise applications and systems, client-server applications, and third-party Internet solutions. These extensions provide a consistent access layer to disparate back-end systems, dramatically reducing development effort. The framework provides support for features such as object-pooling, distributed state and session management, template streaming, and multi-threading enables high-performance, fault-tolerant integration that can scale to tens-of-thousands of users. Corporate IT developers, application vendors, and system integrators can easily build server extensions to iPlanet Application Server in Java or C/C++.

The UIF provides generic function like data pooling and user mapping for the enterprise connectors to use. An enterprise SAP takes generic calls into this UIF-provided functionality and translates it into functions that are specific to a particular backend EIS.

A generic data repository is also provided by the UIF, which is used to hold metadata parameters and other information about the SAP system. For example, this metadata often describes the physical connection between systems, the data that is available, and the methods you can use to process data.

Since backend systems are implemented differently, the details for each EIS implementation differ. The SAP R/3 enterprise connector is based on an out-of-process mechanism that uses workers and daemons.

Architecture of the SAP R/3 Connector

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Besides the UIF module that provides SAP-independent core services, the iPlanet Application Server Enterprise Connector for SAP R/3 includes its own API that you can use to access data, and an implementation of the repository which you use to mine for data and specific data access services that can be used to drive the connector.

The iPlanet Application Server enterprise connector for SAP R/3 allows you to build interactive web-based eBusiness applications, as well as analytical applications for human resource management, financial, distribution, manufacturing, and supply chain management within an enterprise system. Specifically, the iPlanet Application Server Enterprise Connector for SAP R/3 allows you to retrieve, display, and manipulate data within a SAP transaction that is initiated by an EJB or servlet and is served by the iPlanet Application Server.

The iPlanet Application Server enterprise connector for SAP R/3 stores data that defines the services available to an iPlanet Application Server servlet or EJB from a SAP R/3 system in the repository. Repository data includes two types of metadata definitions:

• Connector types
  These define SAP-specific characteristics, including the kinds of operations that are available (function-object types) and the kinds of logical connections that are supported (service-provider types).

• Data sources
  These define the logical data source that specifies data and business functions available on a specific backend system.

A set of enterprise tools provides graphic user interfaces to help you manipulate the enterprise connector-enabled SAP functionality.

Enterprise Connector Tools for SAP R/3

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The Enterprise Connector Tools that are used for data mining, user mapping, and general configuration include the:

• Repository Browser

• SAP R/3 Management Console

• SAP R/3 Data mining Tool (this is part of the Management Console)

Repository Browser

The Repository Browser allows you to view the contents of the repository, import and export XML files, and delete nodes. A typical Repository Browser is shown below:

Figure 1-3    Repository Browser

You can:

• import XML, which is converted into nodes, and subtrees

• export as XML all subtrees under a node

• delete nodes

• import root nodes

SAP R/3 Management Console

The SAP R/3 Repository Management Console allows you to browse or change the SAP configuration. The SAP R/3 Management Console is shown below:

Figure 1-4    SAP R/3 Management Console

You can:

• convert data to XML

• create new data sources

• edit existing data sources

SAP R/3 Data mining Tool

The SAP R/3 Data mining Tool, which is part of the Management Console, allows you to determine the available transactions on the SAP R/3 system and to load this metadata into the repository.

The elements of the data mining are shown in the following illustration.

Figure 1-5    Elements of the Data Mining

The user submits search criteria to the Management console which queries SAP R/3 for any functions that match the criteria. The user then selects the function or functions to be mined. The functions are mined, converted to XML, and then loaded into the repository.