SAP Portal - FAQ 3

What exactly is the SAP Web Application Server?
The SAP Web Application Server is the reliable, open standard-based application server from SAP. It supports both J2EE and ABAP, and serves as the underlying infrastructure for all new and upcoming SAP solutions, like SAP R/3 Enterprise, SAP Portal, SAP Exchange Infrastructure, and all other SAP components. The SAP Web Application Server is not a new product, it is the natural evolution of proven SAP application server technology formerly known as SAP Basis. It provides the platform to develop, execute, and operate Web applications and Web services as well as traditional SAP GUI based applications

Does the SAP Web Application Server replace the SAP Internet Transaction Server (SAP ITS)?
No, the SAP Internet Transaction Server (SAP ITS) will continue to be supported in the future and is integrated into Web Application Server from version 6.40 on. This is because the SAP ITS will in future display Dynpro-based SAP applications to the Web, either using the HTML-GUI or with HTML-template based IACs. This integration reduces the additional hardware for an external ITS. All SAP ITS based applications and the administration will work as before.

Flow Logic technology will also not be supported by the SAP Web Application Server. ITS Flow Logic is an approach to Web application development that is now completely covered by the new "Business Server Pages" technology and others. New applications based on ITS Flow Logic are no longer developed by SAP. Existing applications based on ITS Flow Logic will continue to be supported. SAP recommends customers use the Business Server Pages for new projects or projects in an early stage of development instead of ITS Flow Logic.

Will my application run on SAP Web AS?
The SAP Web Application Server is the foundation for all new and upcoming SAP solutions, like SAP R/3 Enterprise (MySAP ERP respectively), SAP Portal, SAP Exchange Infrastructure, and all other SAP components. Basically an SAP application will run on top of the SAP Web Application Server, if SAP ships the application or solution based on the SAP Web Application Server (for current information about SAP components availability see: Platform and Technology Information Center.

Furthermore, a non-SAP application that is based on J2EE could run on the Web Application Server if this application is J2EE compliant.

SAP Web Application Server 6.40 provides a J2EE Engine which is an J2EE 1.3-compliant application server, that is, every J2EE-1.3 compliant application will run on it. The only thing to do is configure external resources used by your application (for example, the database, the JMS resource) inside SAP Web Application Server 6.40 and to (re)deploy your application on SAP Web Application Server 6.40. However, many third party J2EE application servers provide additional, proprietary server functions, making applications possibly not immediately portable. Check if your J2EE 1.3 application is using such non-standard extensions.

Will my SAP application also run on third party application servers?
There are two cases here to consider. If your application is written in ABAP the answer clearly is no. If your application is written in Java the answer is not that easy. Any J2EE application can of course be ported to other servers. This definitely means that there will be some porting effort, dependent on the specific case and the J2EE technologies used. SAP will not automatically support this.

Be aware that J2EE will help a lot to standardize your application but at the same time will not guarantee a seamless port-by-copy approach.

Should I use Java or ABAP as the programming language for Web application development?
The Java development and runtime environment is gradually being built up, extended, and integrated in the SAP Web Application Server by SAP. However, it will still take some time in the market before the Java/J2EE platform offers the performance and reliability that the ABAP environment has already had for a long time.
On the other hand Java development today is preferred for many projects done in the corporate area. Your decision on using one or the other should be based on the kind of resources you have available.

When mixing technologies it is a good idea to do a proof of concept for that project to be sure that it works in the way you expect.

Does SAP Web Application Server available for High Availability (HA)?
Yes, there are several measures to prevent unplanned downtimes eliminating single points of failure. Basically, all critical system components of the SAP Web AS can be configured redundantly. When one single component crashes a remaining component can take over the tasks of the failed one. The SAP Web AS can be used both in local fail-over and disaster recovery scenarios.
More information can be found in sapnet under alias /ha

What are the most important HA features of the SAP Web AS?
The SAP Web AS has built-in scalability and redundancy: Multiple front-ends can run against multiple application servers. Using load-balancing features (logon load balancing and Web Dispatcher), the requests will be directed to the best suitable application server. The database can be protected with common HA measures as clustering, parallel database, or standby databases. After a fail-over of the database, the work processes can reconnect and continue their work. A single SAP Web AS instance itself has a high reliability due to its proven memory management and application isolation features: A failure of a process only affects one single user session

Does SAP guarantee defined availability levels?
No, it is not possible to guarantee availability levels because the customer environments are very different and contain a lot of non-SAP components (for example, hardware, network). However, lots of our customers experience system availability of 99.5% and above.

Could I upgrade my existing SAP solution (for example, R/3 4.5) to the SAP Web Application Server 6.20?
No, this is not possible and was also not possible for previous SAP solutions. Then, the SAP Basis (which is now SAP Web Application Server) was in a composite with the application component. That bundle was shipped as a SAP Solution like R/3 4.5. The upgrade was always an upgrade of the whole bundle. This means that to use the SAP Web Application Server features you have to install a SAP Web Application Server separately in front of your existing SAP System and connect to that system using RFC, for example. Or you have to upgrade to the SAP solution, which is based on the SAP Web Application Server like R/3 Enterprise

What is the Web Dynpro?
Web Dynpro is a runtime and development environment for creating easily adaptable Web based user interfaces. The Web Dynpro programming model goes a step further than the server side scripting models by providing graphical design tools that allow the development of the UI independently of the underlying runtime platform. The runtime coding will be generated for all platforms (Java and ABAP) out of these UI definitions.

What are Business Server Pages (BSP)?
The "Business Server Pages" (BSP) programming model is the server side scripting technology of the SAP Web Application Server. This has advantages when existing SAP logic, data structures and interfaces need to be implemented in a "native" Web application. A BSP page usually consists of HTML text which includes ABAP as a server side scripting code in special tags. The scripting code allows direct to access to all elements (function modules, database tables, ABAP objects, and so on) in the application server. It combines the advantages of the trusted SAP development environment with the well-known page-based approach for Web application development (like Microsoft ASP, Java JSP).

What is the benefit of using the SAP Java Tag Library or the BSP Extensions compared to plain HTML?
The HTMLB library provides predefined UI elements (Buttons, Input Fields, Tables) for JSPs and BSPs which speed up the development of typical Web applications enormously. Additionally, the HTMLB library allows the development of Web applications with a consistent look and feel, even in bigger development teams.