SAP Netweaver is based on three integration layers and an application platform. The application platform,which is provided through the SAP Web Application Server (Web AS),is the foundation of Netweaver and is the application platform for the mySAP Business Suites. The application platform supports Java 2 Enterprise Edition (J2EE) and Advanced Business Application Programming (ABAP) in one common environment. The application platform is available on all major databases and operating systems.
The Web AS provides you with three installation options:
SAP Web AS ABAP – one infrastructure for ABAP for all development of ABAP applications. This installation option only has one database schema.
SAP Web AS ABAP and Java – a combined infrastructure of ABAP and Java for all kinds of ABAP and Java development including J2EE applications. The database has an ABAP and a Java schema.
SAP Web AS Java – one infrastructure for all kinds of Java development including J2EE applications. The database has only one Java schema.
In addition to the different installation options, new and enhanced features have been added to the application platform which require that customers understand the way in which the administration of the Web AS is handled. This article will focus on topics concerning the administration of the Web AS ABAP and Java installation.
Let's start by taking a look at some of the components that make up the application platform, i.e. the Web Application Server.
The Presentation Layer, which provides a user interface to the Web AS, can be developed using J2EE standards with Java Server pages (JSP) or the ABAP Business Server Pages (BSP) or Web Dynpro technology.
The Business Layer, which runs on the Web AS, handles the business logic and can be accessed from client applications or other components and third-party applications. The business layer consists of a J2EE runtime environment that processes requests that are passed from the Internet Communication Manager (ICM) and dynamically generates responses. Business logic can be implemented using the J2EE standard with components like Enterprise Java Beans (EJB) or Servlets or by the business objects of applications running in the ABAP environment.
A part of the Internet Transaction Server, SAPGUI for HTML, is included in the SAP Web Application Server, which allows customers to run the classic screen-based application directly using a browser without the need of the Internet Transaction Server.
The Internet Communication Manager (ICM) handles dispatching of user-interface request such as HTTP(s), XML and SOAP. The ICM also provides caching capabilities that enhance the performance of the Web AS.
The amount of administration required will depend on the installation option that has been chosen. As mentioned earlier, this article focuses on the administration for a SAP Web AS ABAP and Java installation and specifically on the administration of the Java instance.
The J2EE instance consists of a dispatcher process and one or more server processes. The processes all run together on one host and are started and stopped together as one unit. All server processes of each instance of the system are grouped together in a cluster. In addition to the processes of the J2EE engine, there are standard communication ports that are created during installation. The system uses an internal port calculation to determine the required ports, which helps to prevent port conflicts. The system uses an internal port_index and system number for the calculation. For example, 50000+100*snr+port_index.
Example results:
Admin Tool: port 50004
Telnet: port 50008
Ports used by the J2EE engine can also be configured individually using the Visual Administrator, which is a tool that can be used to administer the Java instance. Another component of the J2EE Engine is the Software Deployment Manager (SDM), which runs on a Java instance and must be configured to manage the Deployment of Java2EE applications.
As the system offers both ABAP and J2EE, each instance must contain an Internet Communication Manager (ICM) that receives the web request and distributes the request appropriately. The operation of the J2EE Engine also requires that the following services are configured in order to active the Java instance in the Web AS:
/sap/public/icm - enables the ICM to forward requests to the J2EE server
/sap/public/icf_info - used to supply the SAP Web Dispatcher with logon
information such as server load and logon groups. The services are configured on the Web AS using transaction SICF.
Starting and stopping the J2EE in a Windows environment can be performed using the SAPMMC. With an installation on Unix, the start and stop is performed with the scripts startsap and stopsap. Starting the SAP Web AS Java with the ABAP also requires that the system parameters rdisp/j2ee is set. This parameter invokes the J2EE Startup and Control Framework, which includes the JControl and the JLaunch programs. JControl starts the Jlaunch. Jlaunch then starts a Java program which loads the JVM into its own address space, and then the J2EE cluster elements (i.e. dispatcher and server processes) are started. Starting and stopping the J2EE engine processes can also be performed using the ICM monitor transaction SMICM and is independent of the operating system.
The system workload may require that more than one Web Application Server ABAP and Java is installed in your system environment to provide better system performance. To help manage the distribution of the workload, the SAP Web Dispatcher can be configured. The SAP Web Dispatcher, which is the executable program sapwebdisp, is installed as part of the kernel installation and should be configured on a computer in the DMZ. The Web Dispatcher acts as a Web Switch and creates a single point of access to your systems. The Web Dispatcher requires a profile that contains parameters that help determine the most efficient distribution of your work load. This profile must contain parameter that specifies the HTTP port of the SAP message server.
Other administration tasks include configuring additional server processes, threads, pool sizes, thresholds, ports, log and trace configuration. Configuration and administration of the Change Management Service (CMS), which is used for transporting the Java development and monitoring the Java environment, are additional required administration tasks. The combined infrastructure for the J2EE and ABAP environments of the Web AS provides centralized and unified installation, configuration, monitoring, security, and load balancing for both programming environments.
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To receive more information on training for the Administration of the Web Application Server, check out the SAP Education Web Site at www.sap.com/usa. This site is constantly updated with new offerings. To speak to a SAP Education Representitive, please contact the SAP Education Help Desk at 1-877-876-7271.
