adm800 - administration as java 7.1(col74)

ADM800Administration AS Java 7.1

SAP NetWeaver

Date

Training Center

Instructors

Education Website

Instructor HandbookCourse Version: 74Course Duration: 5 Day(s)Material Number: 50099327Owner: Sascha Tubbesing (d038680)

An SAP Compass course - use it to learn, reference it for work

Copyright

Copyright 2011 SAP AG. All rights reserved.

No part of this publication may be reproduced or transmitted in any form or for any purpose without theexpress permission of SAP AG. The information contained herein may be changed without prior notice.

Some software products marketed by SAP AG and its distributors contain proprietary softwarecomponents of other software vendors.

Trademarks

Microsoft, WINDOWS, NT, EXCEL, Word, PowerPoint and SQL Server areregistered trademarks of Microsoft Corporation.

IBM, DB2, OS/2, DB2/6000, Parallel Sysplex, MVS/ESA, RS/6000, AIX, S/390,AS/400, OS/390, and OS/400 are registered trademarks of IBM Corporation.

ORACLE is a registered trademark of ORACLE Corporation. INFORMIX-OnLine for SAP and INFORMIX Dynamic ServerTM are registered trademarks

of Informix Software Incorporated. UNIX, X/Open, OSF/1, and Motif are registered trademarks of the Open Group. Citrix, the Citrix logo, ICA, Program Neighborhood, MetaFrame, WinFrame,

VideoFrame, MultiWin and other Citrix product names referenced herein are trademarks ofCitrix Systems, Inc.

HTML, DHTML, XML, XHTML are trademarks or registered trademarks of W3C, World WideWeb Consortium, Massachusetts Institute of Technology.

JAVA is a registered trademark of Sun Microsystems, Inc. JAVASCRIPT is a registered trademark of Sun Microsystems, Inc., used under license for

technology invented and implemented by Netscape. SAP, SAP Logo, R/2, RIVA, R/3, SAP ArchiveLink, SAP Business Workflow, WebFlow, SAP

EarlyWatch, BAPI, SAPPHIRE, Management Cockpit, mySAP.com Logo and mySAP.com aretrademarks or registered trademarks of SAP AG in Germany and in several other countries allover the world. All other products mentioned are trademarks or registered trademarks of theirrespective companies.

Disclaimer

THESE MATERIALS ARE PROVIDED BY SAP ON AN "AS IS" BASIS, AND SAP EXPRESSLYDISCLAIMS ANY AND ALL WARRANTIES, EXPRESS OR APPLIED, INCLUDING WITHOUTLIMITATION WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULARPURPOSE, WITH RESPECT TO THESE MATERIALS AND THE SERVICE, INFORMATION, TEXT,GRAPHICS, LINKS, OR ANY OTHER MATERIALS AND PRODUCTS CONTAINED HEREIN. INNO EVENT SHALL SAP BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL,CONSEQUENTIAL, OR PUNITIVE DAMAGES OF ANY KIND WHATSOEVER, INCLUDINGWITHOUT LIMITATION LOST REVENUES OR LOST PROFITS, WHICH MAY RESULT FROMTHE USE OF THESE MATERIALS OR INCLUDED SOFTWARE COMPONENTS.

g201124112658

About This HandbookThis handbook is intended to complement the instructor-led presentation of thiscourse, and serve as a source of reference. It is not suitable for self-study.

Typographic ConventionsAmerican English is the standard used in this handbook. The following typographicconventions are also used.

Type Style Description

Example text Words or characters that appear on the screen. Theseinclude field names, screen titles, pushbuttons as well asmenu names, paths, and options.

Also used for cross-references to other documentationboth internal and external.

Example text Emphasized words or phrases in body text, titles ofgraphics, and tables

EXAMPLE TEXT Names of elements in the system. These include reportnames, program names, transaction codes, table names,and individual key words of a programming language,when surrounded by body text, for example SELECTand INCLUDE.

Example text Screen output. This includes file and directory namesand their paths, messages, names of variables andparameters, and passages of the source text of a program.

Example text Exact user entry. These are words and characters thatyou enter in the system exactly as they appear in thedocumentation.

Variable user entry. Pointed brackets indicate that youreplace these words and characters with appropriateentries.

2011 2011 SAP AG. All rights reserved. iii

About This Handbook ADM800

Icons in Body TextThe following icons are used in this handbook.

Icon Meaning

For more information, tips, or background

Note or further explanation of previous point

Exception or caution

Procedures

Indicates that the item is displayed in the instructorspresentation.

iv 2011 SAP AG. All rights reserved. 2011

ContentsCourse Overview ............................................................................. vii

Course Goals.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .viiCourse Objectives ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Unit 1: Fundamentals..........................................................................1Fundamental Concepts of Java... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3Architecture of the SAP NetWeaver Application Server .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Java Cluster Architecture .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30The Internal Structure of SAP NetWeaver AS Java... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Load Balancing in the SAP NetWeaver AS Java Environment .. . . . . . . . . . . . . . . . . . . . . . 45

Unit 2: Starting and Stopping.............................................................. 59Overview of the Process for Starting and Stopping an SAP NetWeaver AS Java . 61Tools for Starting and Stopping ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Java Startup and Control Framework ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89Logs of the Start and Stop Processes of SAP NetWeaver AS Java ... . . . . . . . . . . . . .100

Unit 3: Basic Configuration ............................................................... 111Overview of the Administration Tools .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Basic Configuration of AS Java with the Config Tool .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132Further Configuration Activities .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160

Unit 4: Secure Infrastructure .............................................................181Network Security.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .183Setting Up SSL... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193

Unit 5: User and Authorization Administration.......................................225Structure and Configuration of the User Management Engine (UME)... . . . . . . . . . . .227User and Group Administration ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .254The Java Authorization Concept.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .269Special Principles.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .284Logon Procedure of the AS Java ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .299

Unit 6: Java Connector and Destinations..............................................333Connections to other Systems ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .335

2011 2011 SAP AG. All rights reserved. v

Contents ADM800

Appendix: Connections to other Systems with the Java Connector Architecture .352

Unit 7: Change Management and Software Logistics...............................367Overview of the Standard Java EE Development Process ... . . . . . . . . . . . . . . . . . . . . . . .374Introduction to SAP NetWeaver Development Infrastructure (NWDI) .. . . . . . . . . . . . .391Preparing for the Development of Java Applications ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .429Developing Java Objects in SAP NetWeaver Developer Studio .. . . . . . . . . . . . . . . . . . .467Transporting Java Developments .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .495Addendum: The Use of Change Management Service for the Transport of Java

Applications ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .524

Unit 8: Monitoring ...........................................................................549Monitoring SAP NetWeaver AS Java ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551Connecting to a Central Monitoring System ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .565Log Viewer and Log Configuration ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .583Availability Monitoring ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .607

Unit 9: Software Maintenance ............................................................625Importing Corrections ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .626Backing Up AS Java ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .651

Glossary .......................................................................................661

Index ............................................................................................663

vi 2011 SAP AG. All rights reserved. 2011

Course OverviewThis course provides an overview of the various tasks of the system administration forsystems that are based on SAP NetWeaver AS Java 7.1x. This course provides a solidfoundation for the training of system administrators of SAP NetWeaver AS Java 7.1x.This course deals with the basic activities that affect SAP NetWeaver AS Java 7.1x.However, no application-specific or product-specific activities are taught.

Target AudienceThis course is intended for the following audiences:

Administrators and consultants for SAP systems that are based on SAPNetWeaver AS Java 7.1x, for example SAP NetWeaver CE 7.1x and SAPNetWeaver PI 7.1x

Course PrerequisitesRequired Knowledge

SAPTEC - Fundamentals of SAP NetWeaver Application Server

Recommended Knowledge

ADM100 - Administration AS ABAP I

Course Duration DetailsUnit 1: FundamentalsFundamental Concepts of Java 25 MinutesArchitecture of the SAP NetWeaver ApplicationServer 20 Minutes

Java Cluster Architecture 20 MinutesThe Internal Structure of SAP NetWeaver AS Java 15 MinutesLoad Balancing in the SAP NetWeaver AS JavaEnvironment 20 Minutes

Unit 2: Starting and StoppingOverview of the Process for Starting and Stoppingan SAP NetWeaver AS Java 20 Minutes

Tools for Starting and Stopping 20 MinutesExercise 1: Tools for Starting and Stopping 10 MinutesJava Startup and Control Framework 35 Minutes

2011 2011 SAP AG. All rights reserved. vii

Course Overview ADM800

Exercise 2: Java Startup and Control Framework 10 MinutesLogs of the Start and Stop Processes of SAPNetWeaver AS Java 15 MinutesExercise 3: Logs of the Start and Stop Processes ofSAP NetWeaver AS Java 10 Minutes

Unit 3: Basic ConfigurationOverview of the Administration Tools 50 MinutesExercise 4: Calling the Administration Tools 15 MinutesBasic Configuration of AS Java with the Config Tool 90 MinutesExercise 5: Configuration with the Config Tool 30 MinutesFurther Configuration Activities 60 MinutesExercise 6: Further Configuration Activities 15 Minutes

Unit 4: Secure InfrastructureNetwork Security 25 MinutesSetting Up SSL 90 MinutesExercise 7: Setting up SSL 30 Minutes

Unit 5: User and Authorization AdministrationStructure and Configuration of the UserManagement Engine (UME) 60 MinutesExercise 8: User Management Engine 30 MinutesUser and Group Administration 45 MinutesExercise 9: User and Group Administration 15 MinutesThe Java Authorization Concept 25 MinutesExercise 10: Create and Assign UME Roles 15 MinutesSpecial Principles 45 MinutesExercise 11: Default Principles and EmergencyUsers 15 Minutes

Logon Procedure of the AS Java 120 MinutesExercise 12: Configuration of X.509 ClientAuthentication 15 Minutes

Unit 6: Java Connector and DestinationsConnections to other Systems 60 MinutesExercise 13: Connections to other Systems 30 MinutesAppendix: Connections to other Systems with theJava Connector Architecture 30 MinutesExercise 14: Optional: Connections to otherSystems with the Java Connector Architecture 30 Minutes

Unit 7: Change Management and Software LogisticsOverview of the Standard Java EE DevelopmentProcess 25 Minutes

viii 2011 SAP AG. All rights reserved. 2011

ADM800 Course Overview

Introduction to SAP NetWeaver DevelopmentInfrastructure (NWDI) 80 MinutesExercise 15: Checking the Settings on SystemLandscape Directory 10 Minutes

Preparing for the Development of Java Applications 80 MinutesExercise 16: Preparing for the Development of JavaApplications 15 Minutes

Developing Java Objects in SAP NetWeaverDeveloper Studio 85 MinutesExercise 17: Developing Java Objects in SAPNetWeaver Developer Studio 25 Minutes

Transporting Java Developments 55 MinutesExercise 18: Transporting Java Developments 15 MinutesAddendum: The Use of Change ManagementService for the Transport of Java Applications 0 Minutes

Unit 8: MonitoringMonitoring SAP NetWeaver AS Java 45 MinutesExercise 19: Monitoring SAP NetWeaver AS Java 15 MinutesConnecting to a Central Monitoring System 20 MinutesExercise 20: Registering with a Central MonitoringSystem 15 Minutes

Log Viewer and Log Configuration 60 MinutesExercise 21: Log Viewer and Log Configuration 15 MinutesAvailability Monitoring 35 MinutesExercise 22: Availability Monitoring 15 Minutes

Unit 9: Software MaintenanceImporting Corrections 90 MinutesExercise 23: Importing Corrections 30 MinutesBacking Up AS Java 10 Minutes

2011 2011 SAP AG. All rights reserved. ix


Course GoalsThis course will prepare you to:

Explain the architecture of SAP NetWeaver AS Java Start and stop SAP NetWeaver AS Java Carry out basic configurations for SAP NetWeaver AS Java Classify network security concepts Set up SSL encryption for SAP NetWeaver AS Java Explain the architecture of the User Management Engine Configure the User Management Engine Carry out user and authorization maintenance Understand and change the standard logon procedure of SAP NetWeaver AS Java Maintain destinations and the JCo RFC Provider Understand the architecture and the tasks of the SAP NetWeaver Development

Infrastructure Explain the process flow of the development process using the SAP NetWeaver

Development Infrastructure Specify the options for monitoring SAP NetWeaver AS Java Connect SAP NetWeaver AS Java to a central Monitoring system Display Monitoring and logging data using the SAP NetWeaver Administrator Implement corrections for SAP NetWeaver AS Java

Course ObjectivesAfter completing this course, you will be able to:

Explain the architecture of SAP NetWeaver AS Java Start and stop SAP NetWeaver AS Java Carry out basic configurations for SAP NetWeaver AS Java Classify network security concepts Set up SSL encryption for SAP NetWeaver AS Java Explain the architecture of the User Management Engine Configure the User Management Engine Carry out user and authorization maintenance Understand and change the standard logon procedure of SAP NetWeaver AS Java Maintain destinations and the JCo RFC Provider

x 2011 SAP AG. All rights reserved. 2011

ADM800 Course Overview

Understand the architecture and the tasks of the SAP NetWeaver DevelopmentInfrastructure

Explain the process flow of the development process using the SAP NetWeaverDevelopment Infrastructure

Specify the options for monitoring SAP NetWeaver AS Java Connect SAP NetWeaver AS Java to a central Monitoring system Display Monitoring and logging data using the SAP NetWeaver Administrator Implement corrections for SAP NetWeaver AS Java

Caution: The instructor notes in the manual were created in parallel with thedocuments for the participants. Additional information, which is (currently)available on SAP Service Marketplace under the quick link /curr-adm, isalso required. This includes:

General information about the system landscape and logon data A System Setup Guide with all the preparatory steps (Possibly) an add-on IG with supplements and error corrections for the

course material A registration list for newsflash emails about administration training

If you do not have access to this information, contact your local trainingadministration. You cannot teach this course without the additionalinformation.

You must be well prepared to teach this challenging course. The challenge is thatwith many new SP statuses for this course, there have been/will be changes. Thereare a lot of minor and major differences between SAP NetWeaver AS Java 7.0x and7.1x. However, these differences are not referred to in great detail. This is not a deltacourse. Course ADM200 deals with Release 7.0x.

2011 2011 SAP AG. All rights reserved. xi


To prepare for this course, we strongly recommend that you go through the coursewith an experienced instructor beforehand. It would also be useful to attend ADM200to take a look at the release differences.

Unit 1:

Added Gateway to slides

Unit 2:

New screenshots from 7.11

New sapcontrol slide and exercise like in ADM200

Unit 3:

New screenshots from 7.11

Unit 4:

SSL Exercise: some buttons changed in NWA

Unit 5:

Last Lesson: Removed SPNego exercise. Added X.509 information andexercise.

Unit 6:

Spelling corrections

Unit 7:

Major changes! Check instructor notes in Unit and lessons carefully!

Unit 8:

NWA UI in 7.11 is different, therefore some changes in Loggin/Tracing.

Central Monitoring works different with SolMan 7.01. RZ21 works different.No SAPCCMSR any more!

Removed last Lesson on SolMan as there are too much changes in this area.See SM100 and E2E100 for more information on Central Monitoring featureswith SAP Solution Manager!

Unit 9:

Only minor changes. Only mentioning Mopz, not doing anything with it.

xii 2011 SAP AG. All rights reserved. 2011

Unit 11 Fundamentals

The aim of this unit is to explain the architecture of AS Java 7.1x. The basic Javaterms and how SAP uses them should be clear to the participants.

Unit OverviewSAP NetWeaver Application Server is a scalable and reliable component platform. Itprovides a complete development infrastructure, to develop, distribute, and executeplatform-independent, robust, and scalable Web services and business applications.SAP NetWeaver Application Server supports both ABAP and Java and Web services.To do this, the classic SAP Basis was extended with the Internet CommunicationManager (ICM) for SAP Web Application Server 6.10. In the next evolutionary step,SAP Web Application Server was extended with the SAP Web Application ServerJava for SAP Web Application Server 6.20. As of Release 6.40, SAP NetWeaver ASABAP and SAP NetWeaver AS Java is a central component of SAP NetWeaver.

This unit describes the technical fundamentals and the architecture of AS Java 7.1x.

Unit ObjectivesAfter completing this unit, you will be able to:

Use basic Java terminology Explain the architecture of SAP NetWeaver Application Server Explain the term Central Services of SAP NetWeaver AS Java Understand and use concepts such as Java instance, ICM, and server Name the most important managers of the SAP NetWeaver AS Name the most important services of the SAP NetWeaver AS Explain how load balancing can be realized in the SAP system

2011 2011 SAP AG. All rights reserved. 1

Unit 1: Fundamentals ADM800

Unit ContentsLesson: Fundamental Concepts of Java ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3Lesson: Architecture of the SAP NetWeaver Application Server .. . . . . . . . . . . . . 20Lesson: Java Cluster Architecture.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Lesson: The Internal Structure of SAP NetWeaver AS Java ... . . . . . . . . . . . . . . . 37Lesson: Load Balancing in the SAP NetWeaver AS Java Environment.. . . . . 45


ADM800 Lesson: Fundamental Concepts of Java

Lesson:2

Fundamental Concepts of JavaLesson Duration: 25 Minutes

Lesson OverviewThis lesson provides a short overview of the fundamental Java concepts for allparticipants that have not yet been confronted with Java. The architectural conceptand the properties of Java are briefly outlined.

Lesson ObjectivesAfter completing this lesson, you will be able to:

Use basic Java terminology

Many participants in the course will probably not yet be familiar with basic Javaterminology. As an introduction to the new Java world, the basic Java terms areintroduced in this lesson. This should make the introduction to the Java terminologyworld in the SAP environment easier for the participants.

Business ExampleAs of SAP Web Application Server 6.20, you have the option of using Java as well asthe ABAP programming language. You should therefore familiarize yourself with thefundamental concepts of the Java environment.

IntroductionIf you search for the meaning of the word Java in an encyclopedia, you find thefollowing definitions, among other things:

One of the four main islands of the Indonesian republic in the Indian Ocean. A programming language developed by the company Sun Microsystems. An aromatic type of coffee, particularly used to make espresso. A popular dance of the 1920s. A coarse, loose mesh canvas for embroidery, made of linen or cotton.

It would undoubtedly be worthwhile to investigate each of these definitionsindividually in more detail. In this course, we want to concentrate exclusively onthe second definition in this list.



The Java programming language was first introduced in 1995 by Sun MicrosystemsInc.. Java is an object-oriented and platform-independent programming languagethat has spread across many areas. The powerful concept of Java allows thedevelopment of a large number of different types of application - from the classicapplication using applets implemented in Web pages to client/server applications.

Java has been designed to be platform independent. This means that the same Javaprogram can be executed on any system for which a Java Runtime Environment(JRE) is available. In particular, Java applications can run on different systems thatare based on different hardware. Java can be used to create programs for UNIX,Microsoft Windows, Linux, MacOS, or OS/2, for workstations or servers; for x86,MIPS, Alpha, or Sparc; for computers, organizers, or cell phones, and for the microcomputers built into household and industry devices, such as washing machines,video recorders, cars, and traffic lights.



Properties of JavaYou need to differentiate between two basic types of Java programs: applicationsand applets.

Applications

Java applications are computer programs with the full functional range alsoprovided by other programming languages. Applications can run as localprograms on the users computer or as client/server systems across the Internetor using an Intranet, or as server programs (servlets, CGI programs) on a Webserver.

Applets

The term applet essentially means "little application". It usually means a Javaapplet, a small computer program that runs in a Web browser and is written inthe Java programming language. Java applets are intended for execution withinthe Java Runtime Environment of a browser. They are transferred (as is also thecase, for example, with embedded images) with the HTML page using the HTTPprotocol, and then executed on the client computer. Special security guidelinesapply to Java applets; that is, they are not permitted to perform everything on theclient that locally-installed programs are permitted to. In this way, for example,they can only create network connections to the host from which they weredownloaded.

Hint: You need to be careful when using the name Java. Not everythingthat has Java as its linguistic root is actually connected to Java; JavaScriptis completely unrelated to Java. JavaScript is a script language that can beembedded in HTML and, with some Web browsers (Netscape, MicrosoftInternet Explorer), produces the execution of certain functions and actionswithin the Web browser. JavaScript was developed with the intention ofdynamically organizing static HTML pages. Unlike server-side scriptlanguages such as Perl or PHP, JavaScript is executed on the client. Incontrast to Java, JavaScript is not an independent programming language,is not independent of the browser version, and does not have the requiredsecurity mechanisms.

Initially, Java is a programming language like any other. Unlike traditional compilersfor a programming language, which generate machine code for a specific platform (seethe Compiled Programming Languages figure), the Java compiler produces programcode for a virtual machine (the Java Virtual Machine). This is known as bytecode. Avirtual machine is a model of a processor (which often does not exist as real hardware)and the associated system architecture. It is a computer program that emulates aprocessor. The effort required to transfer this software to other real CPUs is small in



comparison. The virtual machine is therefore viewed as the interface between Java andthe actual hardware. It must therefore be developed for each processor architectureand, as such, is the only platform-dependent component of a Java development system(see the figure Concept of the Java Virtual Machine).

SAP also uses the concept of a cross-platform virtual machine in the ABAP world.The ABAP programs of the SAP system are also converted into a bytecode, which isinterpreted by the ABAP Virtual Machine, the ABAP work process.

Figure 1: Compiled Programming Languages

Hint: Virtual machines play an important role nowadays, since Microsoft hasfollowed Suns example of the Java Virtual Machine (Java VM) with its .NETarchitecture. The concept of the virtual machine was already in use in the late1960s; Martin Richards O code for the BCPL programming language is anearly example. Better-known examples are the Pascal P code system (UCSDPascal) from the 1970s, and the virtual machine on which programs in theSmalltalk programming language run.

The bytecode generated by the Java compiler is comparable to microprocessorcode for a conceived processor , which understands instructions such as arithmeticoperations, gotos, and so on. A Java compiler, such as the one from Sun, which is



itself implemented in Java, generates this bytecode. However, so that the programcode of the virtual processor can be executed, after the conversion phase, the runtimeenvironment (also known as the runtime interpreter), the Java Virtual Machine, runsthe bytecode. In this way, Java is a compiled, but also an interpreted programminglanguage.

Figure 2: Concept of the Java Virtual Machine

The interpretation causes speed problems, since the identification, decoding, andexecution of the commands takes time. Java programs are generally slower thanprograms that were converted specifically for the target environment (such as C(++)programs). The technology of the Just In Time (JIT) compiler alleviates the problem.A JIT compiler accelerates the execution of the programs by converting the programstatements of the virtual machine for the physical machine. There is then a programadjusted for the architecture available in memory, which is executed quickly withoutinterpretation. Even with this technology, the speed is slower than that of C in manycases, but the difference is smaller.

A Java Development Kit (JDK) is required to write platform-independent Javaprograms. The Java Development Kit includes the software required to create and testJava applications and applets, the packages with the Java classes that are part of thebasic configuration, and the online documentation. The software includes the Javacompiler, the Java Runtime Environment (the Java Virtual Machine) for running



applications, the applet viewer for running applets, a Java debugger, and variousutilities. The online documentation describes all language elements and all classes ofthe Application Program Interface API.

Java is a relatively new programming language and is therefore still in development,that is, new versions with extensions and improvements are constantly being released:the original version is JDK 1.0 (1995). Since Version 1.2, the JDK has also beencalled Java Platform 2 and in Version 1.3.0 to Version 1.4, the JDK is called Java 2Software Development Kit (SDK). It is called JDK again from Version 1.5.0 andSDK is used in another context. From Version 1.6.0, Java Platform 2 is no longerused, rather Java Platform is used. From Version 1.5.0, there is a differentiationbetween a developer version and a product version with 1.5.0 as the developer version.The related product version is 5.0. Product version 6 belongs to developer version1.6.0.

The above name changes were made by Sun.

Java Standard Edition (Java SE). The standard edition is the normal softwareenvironment and defines the Java SE Development Kit (JDK). This includesthe Java SE Runtime Environment (JRE).

Java Enterprise Edition (Java EE). The enterprise edition builds on the JDKand integrates additional packages such as Enterprise JavaBeans (EJB), servlets,JavaServer Pages (JSP), Java Mail API, and Java Transaction Service (JTS). TheJava EE 5 SDK (Software Development Kit) includes the Sun Java SystemApplication Server and requires a JDK. This can be JDK Version 5.0 or JDKVersion 6 in Version 5.

Java Micro Edition (Java ME). The micro edition is a small runtimeenvironment for small devices such as Personal Digital Assistants (PDAs) ortelephones.

The following figure SDK Structure describes the interaction between the termsJava EE SDK, JDK and JRE.



Figure 3: SDK Structure

The Java SE Runtime Environment is also referred to as JRE and contains the runtimeenvironment to which the JVM and other libraries with which Java applications can beexecuted belong. The JRE cannot be used to develop any Java programs. The JDK isrequired for this. It contains the JRE with the Java compiler javac and other toolswhich are of use for programming. When performing client-server programming, youneed a server. The SDK contains the reference implementation of an applicationserver, namely the Sun Java System Application Server. You can use the JavaEE SDK to program, among other things, Enterprise Java Beans, Servlets andJSP; however, a JDK is required.



Figure 4: AS Java with SAP JVM

SAP NetWeaver AS Java is the SAP implementation for a Java-based applicationserver. SAP NetWeaver AS Java 7.1x is Java EE 5-compliant and was the first(along with Sun) to correspond to this standard. SAP NetWeaver AS Java 7.1x doesnot require a JDK from the operating system manufacturer (unlike its predecessors);instead, the SAP-specific JDK is used on all operating systems.



The SAP Java Virtual Machine (JVM) is a Java Virtual Machine for applicationservers that are reliable, scalable and can be supported for using SAP products. TheSAP JVM implements the standard Java SE 5.0 and provides a reliable foundationfor SAP NetWeaver AS Java. Some of the SAP JVM properties were developedespecially to meet the requirements of SAP customers:

Additional Supportability

The SAP JVM provides functions for supporting complex Java applications.One prominent function here is the extended stack trace. It helps developers toidentify problems and software errors.

Profiling and Memory Debugging

Discovering problems in memory management has the same value as identifyingfunctional errors. Therefore, the SAP JVM provides enhanced options in thearea of performance and memory profiling.

Debugging on demand

You can use the SAP JVM in productive use to switch to and back fromdebugging mode without restarting the VM. This dramatically reduces theamount of effort required for troubleshooting.

In Release 7.1x, the SAP JVM is used for all supported platforms; previously, thevarious VMs of the individual manufacturers (Sun, IBM, HP) were used. For currentinformation about the supported platforms, go to http://service.sap.com/pam

Programming in JavaWhen creating Java programs, the developer first creates a source file in the formatMyProgram.java (see the figure Tools of the Java Development Kit).

At this point, the instructor can show the Java executables (java.exe, jar.exe) on the g:drive and in the directory SYS/Exe/jvm.

The Java compiler generates a separate file for each class from the source file thatcontains the bytecode for this class. The file name is then the name of the class withthe extension .class, and therefore has the format MyProgram.class. In accordance


http://service.sap.com/pam


with the object-oriented approach, Java functions are grouped in classes. Each Javasource file may only contain one public class. The file name of the source file mustthen be the name of this class (which is case-sensitive) with the extension .java.

This bytecode is platform-independent: irrespective of the type of system on whichthe Java compiler was called, the bytecode can also be executed on any other computersystem, at least in the case of 100% pure Java, which unfortunately cannot beguaranteed for all products.

Figure 5: JDK tools

You can also combine multiple class files into a compressed archive file. Java archivefiles of this type then have, for example, names in the format MyArchive.jar. AJava archive contains files and possibly also entire directory structures in the samecompressed format used by PKZIP and WinZip. They are administered with theprogram jar (Java Archiver); the call is similar to that of the UNIX program tar (tapearchiver). It is not usually necessary to extract or unpack archive files: The Javacompiler and the Java Virtual Machine can read and load the class files directly fromthe archive files. For this purpose, the file name of the archive file must be specified ina defined format.

The bytecode of a Java application is executed by calling the Java Virtual MachineJVM (in the Java Runtime Environment JRE) in the format java MyProgram.

In a similar way to sub program libraries in other programming languages, in Javathere are also small Java programs (classes) with precisely defined conventions forthe interfaces that allow reuse in multiple applications (applications and applets).These programs are known as Java Beans.



Java EE SpecificationJava became popular with the Internet as a language of the World Wide Web. Lifecan be added to static HTML pages using Applets and Java Script. By extendingWeb servers with the Common Gateway Interface (CGI), these can perform simpledatabase accesses and display the results formatted in the browser. However, thesetechnologies are limited in the case of simultaneous accesses from very large numbersof users who expect reliable information and quick response times.

Sun provides a solution to these problems in terms of server-side architecture forInternet applications with the Java Platform Enterprise Edition (Java EE). JavaEE is a vendor standard for a complete palette of software components, which areprimarily created in the Java programming language. Sun wishes to ensure thatdevelopments comply with the specification of the Java Enterprise Edition usingcompatibility tests for Java EE.

The purpose of the specifications is to make available a generally accepted frameworkfor developing distributed, multilayer applications with modular components. Clearlydefined interfaces between the components and layers ensure that software componentsfrom different vendors are interoperable, provided they adhere to the specifications.With the Java EE specification, Sun wishes to ensure that Web applications thatconform to the specification run on all Java EE-compatible servers. The applicationlogic is packed in components (Enterprise Java Beans) in accordance with the JavaEE specifications. They represent modular java program components. A containerprovides the components implicitly with the services of the runtime environment.

Three-level client/server architectures for enterprise applications can be realized inaccordance with the Java EE specifications. The Java EE application server forms thecore of these architectures (see the figure Three-Level Java(TM) EE 5 Architecture).



Figure 6: Three-Level Java(TM) EE 5 Architecture

The Java EE application server processes client requests, executes the applicationlogic, and returns the results to the clients. The application data is accessed fromthe database level. The application logic is implemented in the form of EnterpriseJava Beans. These are executed in an EJB Container, which is part of the Java EEApplication Server. The communication between the client and the Java EE is basedon Web standards such as HTTP, HTML, and XML. The Java EE server uses JavaServer Pages (JSP) and Java Servlets to generate HTML pages or XML data. JavaServer Pages and Java servlets are executed in aWeb Container, which is, in turn,part of the Java EE Application Server. Java applets can be included in the HTMLpages that are sent to the Web browser. These applets are executed in the browser.

Java Server Pages (JSP) are a technology developed by Sun, which essentiallyallow the simple dynamic generation of HTML and XML output for a Web server.This technology enables Java code and specific JSP actions to be embedded in staticcontent. The advantage of this technology is that the logic can be implementedindependent of the design. JSP are converted Java source code using a special JSPcompiler. This source code, which corresponds to a Java servlet, is then converted tobytecode by the Java compiler.



Figure 7: Architecture of the Java(TM) EE 5 Application Server

Each application component is executed in a container. These containers provide theapplication components with services in accordance with the Java EE specification.Examples of these services are transaction management, availability, security,scalability, client connection, and database access. This means that the developercan concentrate purely on the application logic and does not need to deal with thesesystem functions.

The following figure shows an example of the processing of a client request bya Java EE Server.



Figure 8: Processing of a Client Request by the Java EE 5 Server

To achieve the aims of quick response times and reliable information, the Java EEapplication server must also provide scalability and reliability in addition to thefunctional side. The Java EE Server must handle clustering and load balancing for this.

Java EE Server in the SAP EnvironmentSAP takes into account the increasing importance of Java for creating businessapplications, together with the larger market of Java developers. SAP began afundamental evaluation of Java as early as 1998 and, since SAP Web ApplicationServer 6.20, provides a complete Java EE-compatible runtime infrastructure. Upto Release SAP NetWeaver AS Java 7.0, they were AS Java J2EE 1.3-compliant;since AS Java 7.1x, they are EE 5-compliant. The architecture of an applicationserver in accordance with the Java EE specification is similar to the ABAP runtimeenvironment used for SAP solutions, since both are platform-independent, executed ina multi-level architecture, and have a separate presentation logic and business logic.



The use of Java EE in SAP technology has the following advantages for SAPNetWeaver Application Server:

The open integration architecture SAP NetWeaver integrates perfectly into theopenness of Java EE.

Java EE is further proof of the strategy of platform-independence pursued bySAP.

The Java EE Connector architecture allows standardized integration of externalapplications.

Web Services technologies are supported directly by Java. The quickly-growing Java community provides simple access to experienced

developers.



Facilitated DiscussionNo moderated discussion.

Discussion QuestionsUse the following questions to engage the participants in the discussion. Feel free touse your own additional questions.

No discussion questions.



Lesson Summary

You should now be able to: Use basic Java terminology



Lesson:16

Architecture of the SAP NetWeaver Application ServerLesson Duration: 20 Minutes

Lesson OverviewThis lesson presents the architecture of SAP NetWeaver Application Server. Particularattention is paid to SAP NetWeaver Application Server Java. SAP NetWeaverApplication Server ABAP is presented here only in as far as it is required for theunderstanding of the rest.


Explain the architecture of SAP NetWeaver Application Server

Present the structure of the SAP NetWeaver Application Server in this lesson, andbriefly describe the functions of the individual components. Then describe the possibleinstallation variants of the SAP NetWeaver Application Server.

In this lesson, you should explain the terms:

SAP NetWeaver AS SAP NetWeaver AS ABAP SAP NetWeaver AS Java SAP NetWeaver AS ABAP+Java

Business ExampleSAP NetWeaver Application Server is the technical basis for many SAP components.To be able to administrate SAP NetWeaver Application Server, you need to understandits internal structure and architecture.

IntroductionYou can implement both server-side and client-side Web applications with the SAPNetWeaver Application Server. Server applications (such as online shops or portals)can be created in the integrated development environment or with an external tool;the Web pages contain dynamic script code in addition to static HTML code. SAPNetWeaver Application Server can - depending on the chosen installation variant -


ADM800 Lesson: Architecture of the SAP NetWeaver Application Server

execute ABAP and/or Java programs. This means that when you are creating Webapplications, you can use both the ABAP-based Business Server Pages and Java-basedprogramming (JSPs, and so on).

SAP NetWeaver Application Server is the application platform of SAP NetWeaver. Itrepresents the basis for the other SAP NetWeaver components.

The following figures show the structure and components of the SAP NetWeaverApplication Server.

Figure 9: Architecture of the SAP NetWeaver Application Server Java



Figure 10: Architecture of the SAP NetWeaver AS ABAP+Java

An SAP NetWeaver AS ABAP+Java system consists of two integrated parts that arereferred to as ABAP Stack or Java Stack.



The individual components and their tasks are briefly presented in the following:

The Internet Communication Manager (ICM) creates contact with theInternet. It can process Web requests as both a server and client. It supportsthe protocols HTTP, HTTPS, IIOP, IIOPSEC, P4SEC, Telnet and SMTP. SAPNetWeaver AS can act as a Web server or client.

The SMTP protocol is only processed by SAP NetWeaver AS ABAP; therefore,it is not used in SAP NetWeaver AS Java. The protocols IIOP, IIOPSEC, P4SECand Telenet are processed by SAP NetWeaver AS Java; therefore, they are notused in SAP NetWeaver AS ABAP.

The ICM forwards incoming requests of the protocols mentioned above to theappropriate stack (ABAP or Java) for processing and sends the response back tothe inquiring partners.

The ABAP dispatcher distributes the requests to the work processes. If allprocesses are busy, the requests are stored in the dispatcher queue.

The ABAP work processes execute the ABAP code. The ABAP message server is used to exchange messages in SAP NetWeaver

AS ABAP and to balance the load in the SAP system with SAP NetWeaver ASABAP und SAP NetWeaver AS ABAP+Java.

The Java server processes are responsible for processing, for example, Javaserver pages, servlets and so on.

An SAP system that contains SAP NetWeaver AS Java has a central servicesinstance that contains a Java message server and a Java enqueue server. TheJava message server is used to exchange messages in SAP NetWeaver AS Javaand to balance the load in SAP systems without an ABAP stack.

The Java enqueue server is responsible for lock management in SAP NetWeaverAS Java.

SAP NetWeaver Application Server with ABAP and JavaThis section describes the architecture of the integrated version of the SAP NetWeaverApplication Server ABAP and Java.

The architecture of a system of this type with one instance is shown in the figureArchitecture of SAP NetWeaver Application Server ABAP+Java. The structure withmultiple instances is outlined in principle in the following figure.



Figure 11: Architecture of SAP NetWeaver AS ABAP+Java with multipleInstances

Each of these integrated SAP NetWeaver AS instances contains the (ABAP) dispatcherand its work processes, which can process ABAP programs, and the ICM with itsserver processes, to which it distributes the incoming Java EE 5 requests.

One of the instances must be installed as the (ABAP) central instance; that is, providethe enqueue service. Alternatively, the system can be set up with the standaloneenqueue server, and without a central instance.

It is, of course, possible to log on to a SAP system of this type not only using theWeb client, but also using SAP GUI. The Java cluster requires a special instance, theCentral Services, to administer locks and transfer messages and data. Finally, all theapplications and data for ABAP and Java each have a schema in a shared database.



The users can log on to the SAP system using either the SAP GUI or a Web client(browser):

Communication with the SAP GUI

The users log on using the message server (load balancing) or directly to theABAP dispatcher, and the work processes process the user input. An additionaltask of the message server is to transmit requests in the ABAP stack.

Processing Web requests

Web requests are received by an Internet Communication Manager (ICM). TheseHTTP(S) requests can be intended for the Internet Communication Framework(ICF), that is, processed in the ABAP work process (such as BSP applicationsor Java EE 5 requests, which are intended for SAP NetWeaver AS Java. TheICM decides where to forward the request using the URL.

The HTTP(S) requests are distributed across all instances of an SAP system usingthe SAP Web Dispatcher. It is the central point of entry to the SAP system fromthe internet. For each incoming request, it must decide on the SAP NetWeaver ASinstance to which it forwards the request. In each case, the ICM of an applicationserver receives the Web requests from the SAP Web Dispatcher. The ICM then usesthe URL to decide whether it should forward the request to the SAP NetWeaver ASABAP or the SAP NetWeaver AS Java for processing.

Installation Variants of SAP NetWeaver ASDepending on what is required of the SAP NetWeaver Application Server, there arevarious installation variants, depending on which installation routine is used.



Figure 12: Installation variants of SAP NetWeaver AS

SAP NetWeaver Application Server ABAP System.

Complete infrastructure in which ABAP-based applications can be developedand used.

An SAP NetWeaver Mobile 7.1x system contains SAP NetWeaver AS ABAP.

SAP NetWeaver Application Server Java System.

Complete infrastructure for developing and using Java EE 5-basedapplications.

An SAP NetWeaver Composition Environment 7.1x system contains SAPNetWeaver AS Java.

SAP NetWeaver Application Server ABAP and Java System.

Complete infrastructure in which ABAP- and Java EE 5-based applicationscan be developed and used. This installation focuses on seamless Java-ABAPintegration.

An SAP NetWeaver Process Integration 7.1x system contains SAP NetWeaverAS ABAP+Java.

Java Developer Workplace

Complete infrastructure for developing and using Java EE 5-based applicationsin a single-user system.



Lesson Summary

You should now be able to: Explain the architecture of SAP NetWeaver Application Server



Lesson:24

Java Cluster ArchitectureLesson Duration: 20 Minutes

Lesson OverviewThis lesson describes the architecture of SAP NetWeaver AS Java. The individualcomponents of SAP NetWeaver AS Java and their functions are introduced. A Javacluster encompasses all Java components of an SAP system.


Explain the term Central Services of SAP NetWeaver AS Java Understand and use concepts such as Java instance, ICM, and server

The instructor should introduce the structure of a Java instance and the components ofa Java cluster in this lesson. The focus here is the architecture, and an overview of thefunctions of the individual components.

In this lesson, you should explain the terms:

Java Cluster Java instance Central Services

Business ExampleAfter the installation of a SAP NetWeaver Application Server Java, configuration isstill required. You should therefore be familiar with the basic architecture of thecluster of SAP NetWeaver Application Server Java.

The Java Instance ConceptSAP NetWeaver Application Server Java takes the instance concept of SAP Basis,which combines multiple components that are monitored, started, and stopped togetherinto an administrative unit.


ADM800 Lesson: Java Cluster Architecture

The following components are part of a Java instance:

The server processes provide the infrastructure in which the Java EE 5applications run.

The Internet Communication Manager distributes the client requests to thefree server processes of the instance.

An instance always runs on one physical server, but there can be multiple instances onone server. Within an SAP system, an instance is defined using the system ID (SID) ofthe SAP system and the instance number. An SAP system consists of a database andone or more instances. These instances can either be purely ABAP or Java instances,or instances with ABAP and Java infrastructure, with the instances of a system alwayshaving the same infrastructure (that is, there is no system that has ABAP instances(without Java) and Java instances (without ABAP).

The Central Services form a special Java instance. They provide the basis ofcommunication and synchronization within a Java cluster. Another special instance isthe instance that is installed first. It is often referred to as the Primary ApplicationServer Instance or PAS for short. Further instances for a system are referred to asAdditonal Application Server Instances or AAS for short.

To ensure high-performance when processing Java requests, the SAP system can bescaled using the number of server processes for each instances or using the numberof instances.

Explain that the terms central instance and dialog instance no longer apply as of7.10 and explain the terms PAS and AAS.

Java Cluster ArchitectureAll Java components of an SAP system are known as a Java cluster. A Java clusterconsists of:

A Java instance with an ICM and at least one server process. The Central Services, which contain a message server and an enqueue server. A database for the central storage of data. Optionally, additional Java instances

The following figures illustrate an installation with several SAP NetWeaver AS Javainstances.



Figure 13: Cluster with Multiple SAP NetWeaver AS Java Instances

Explain the terms "cluster," "instance," "ICM," and "server process" using the filestructure in the training system.

The SAP NetWeaver AS Java is stored in the directory G:\usr\sap\. The instances (Java) are each stored in a separate directory:

PASz.B. G:\usr\sap\CEM\J00 AAS z.B. G:\usr\sap\CEM\J01

The Java part of an instance is stored relative to these instance directories inthe directory ~/j2ee.

The server processes are in the directory ~/j2ee/cluster in the directoriesserver.

Note: The term cluster has grown historically and is not correctly used in theplace of the directory name. As of SAP NetWeaver AS 6.40, a Java clusterrefers to all Java components of an SAP system.

The Central Services (previously SAP Central Services) are located in thedirectory: . G:\usr\sap\CEM\SCS02.



ICM and Server ProcessesClient requests to SAP NetWeaver AS Java are received by ICM. It selects a freeserver process to process the request and creates the connection between the clientand the server process. The ICM distributes new incoming requests to the availableserver processes using a round robin algorithm. If a connection to the client exists,the request is forwarded to the server process that is already processing requests forthis client.

The server process of the SAP NetWeaver Application Server Java runs the Javaapplications. The server processes are implemented as multi-threaded servers and cantherefore process multiple requests in parallel. The system or application threadstake over the processing of the requests.

Central ServicesThe Central Services run on one host and form a separate Java instance. They consistof the Java message server and the Java enqueue server.

The Central Services provide the basis for communication and synchronization for theJava cluster:

The message service administers a list of the ICM and the server processes ofthe Java cluster. It represents the infrastructure for data exchange (small datasetsonly) between the participating nodes. In the case of load balancing between alarge number of Java instances, it also provides the load balancing informationfor the SAP Web Dispatcher.

The enqueue service administers logical locks that are set in a serverprocess by the executed application program. It is also used for cluster-widesynchronization.

The Central Services are essentially required when a Java cluster is installed. Theyare started on a host with a separate system number and the system ID (SID) of theentire system.

Message ServiceThe message service is an individual program used to communicate between theelements of a Java cluster. The message service knows all active Java instances.

The terms message server and message service are used with the same meaning inthe training material. To be precise, the message server is a program/process thatprovides the message service.



The message service performs the following tasks in the Java cluster:

Notification of events that arise in the cluster, for example, if a node of thecluster disappears (due to failure or the instance being shut down), or when aservice is started or stopped.

Communication between different services Forwarding of messages and requests to all participants (broadcast) Prepare logon information for the SAP Web Dispatcher Guaranteed message transmission Exchange of cache information in the cluster

The same technology is used as with the SAP Message Server for the earlier SAPNetWeaver AS versions without Java.

Enqueue ServiceThe enqueue service runs on the Central Services instance of the Java cluster. Itmanages the lock table in the main memory and receives requests for setting orreleasing locks. It uses the tried and tested SAP lock concept.

The terms enqueue server and enqueue service are used with the same meaning in thetraining material. To be precise, the enqueue server is the program or process thatprovides the enqueue service.

The enqueue service has the following tasks:

Internally, it is used for synchronization within the Java cluster The applications can lock objects are release locks again. The enqueue service

processes these requests and manages the lock table with the existing locks.



Lesson Summary

You should now be able to: Explain the term Central Services of SAP NetWeaver AS Java Understand and use concepts such as Java instance, ICM, and server


ADM800 Lesson: The Internal Structure of SAP NetWeaver AS Java

Lesson:30

The Internal Structure of SAP NetWeaver AS JavaLesson Duration: 15 Minutes

Lesson OverviewThis lesson introduces the internal architecture of SAP NetWeaver AS. Thisarchitecture is the foundation for realizing a Java EE 5 application server inaccordance with the Java EE 5 specification.


Name the most important managers of the SAP NetWeaver AS Name the most important services of the SAP NetWeaver AS

In this lesson, the instructor should briefly describe the architecture, emphasizing thefunctions of the managers and services when doing so. Some of these managers andservices can be presented as examples.

Business ExampleSAP NetWeaver AS Java consists internally of several managers and services. Tobe able to configure these managers and services, you should first understand theirsignificance and functions.

IntroductionThe internal structure of SAP NetWeaver AS Java is divided into three logical levels(see the figure Internal Structure of SAP NetWeaver AS Java):

SAP Java Enterprise Runtime - provides fundamental functions of the runtimeenvironment, such as class loading, cluster communication, management ofconfiguration data, and so on .

AS Java System Components - contain interfaces, libraries, services andfacedes.

Applications Layer - relates to the applications that are deployed and run inSAP NetWeaver Application Server Java.



Figure 14: Internal Structure of SAP NetWeaver AS Java

The following general rule applies to the interaction between these three logicalentities in SAP NetWeaver AS Java: higher-level components can use the functions ofthe lower-level layers. On the other hand, the lower levels are not aware of the higherlevels and cannot therefore use their functions.

This rule is a consequence of the start sequence of the individual modules of thesystem. First, the runtime environment is started, then the services are started, andthen the applications are started.

Communication between the individual components takes place using definedApplication Programming Interfaces (APIs). The components of the higher levels usethese APIs to use functions of the lower levels. The AS Java System components usethe Framework APIs to talk to the SAP Java Enterprise Runtime. The applications cantalk with the AS Java System components either using APIs defined by the Java EE5 specifications, or using proprietary SAP APIs.

The functions of these logical levels and their interaction are described in thefollowing.



SAP Java Enterprise RuntimeThe SAP Java Enterprise Runtime provides the core functions of the system.These core functions are realized by multiple subsystems of the lowest level.These subsystems are called managers. A selection of these managers with a shortdescription is listed below:

Log Manager:

manages the process of logging system events. It configures the logging routinesof the kernel. The Log Manager is the first manager that is started during thestartup of SAP NetWeaver Application Server Java.

Application Thread Manager:

manages inbound client requests. Searches for free threads to process inboundrequests. If no threads are free, the requests are buffered in a request queue.

Thread Manager:

manages threads in which internal operations of SAP NetWeaver AS Java areexecuted.

Locking Manager:

Represents the interface between the server process and the enqueue service.

Configuration Manager:

Allows SAP NetWeaver AS Java to store and access data in a relational database.Uses the Open SQL for Java Framework to do this.

Classloading Manager:

Central location for the registration and removal of loaders and referencesbetween them.

Cluster Manager:

Manages the elements of a cluster (server processes) and is responsible for thecommunication in the cluster. It updates information about the status of theindividual elements of a cluster and the services that are provided by it.

Important settings:

element.joinPort: Port with which servers listen for inbound connections. ms.host: Host on which the Java message server runs.

Service Manager

Represents a container in which all services in the cluster are executed.



AS Java System ComponentsThe AS Java System components form the second level within the three-level structureof SAP NetWeaver AS Java. They provide the complete infrastructure for executingJava EE 5 applications and proprietary SAP applications.

Four types of AS Java System components can be classified:

Interfaces:

Agreements that define how different components of SAP NetWeaver AS Javawork together. They do not provide any runtime functions themselves, but ratherare used by services that provide their implementation.

Libraries:

They provide names, classes, and objects within SAP NetWeaver AS Java.These objects are created by the system when it loads the library, or when anobject is first requested.

Services:

The services that SAP NetWeaver AS Java provides for processing requests aredefined and configured using the Services. Service components can access andutilize functions of the runtime environment through the Framework API. Theyare the most important of these four types of AS Java System components.

Facades:

The facades are special APIs that the Java EE API and SAP API use to accesslibraries, interfaces and services.



A selection of the most important services with a short description is listed below:

Security Provider:

Administration of users and groups and authorization administration. Controlsaccess to resources or applications deployed in SAP NetWeaver AS Java.

Monitoring Service:

Allows access to information about the current system status. Provides generaland statistical information, among other things, about the nodes in the cluster,memory utilization, performance, applications, and user connections.

Log Configurator service

Manages the configuration of the logging and tracing mechanism of SAPNetWeaver AS Java.

Deploy Service:

Manages the deployment of Java applications.

EJB Container Service:

Manages all Enterprise Java Beans (session beans, entity beans, andmessage-driven beans), which are executed in the EJB Container of SAPNetWeaver AS Java.

HTTP Provider:

Is responsible for processing HTTP requests.

Applications LayerThe applications form the third level within the architecture of SAP NetWeaver ASJava. The boundary between the applications and the AS Java System components isdefined by the Java EE APIs and a few proprietary SAP APIs. Applications use theseAPIs to utilize the functions of the AS Java System components.



An enterprise application can contain different types of application components:

Servlet: A program module written in the Java programming language, which isused to respond to requests to a Web server in such a way that the content of thereturned HTMLWeb page is dynamically generated. Servlets are standardized inthe context of the Java EE 5 specification.

Java Server Pages (JSP): Technology for dynamically generating HTML andXML output of a Web server. This technology enables Java code and specificJSP actions to be embedded in static content. The advantage of this technologyis that the logic can be implemented independent of the design. Java ServerPages are converted to Java source code, which corresponds to a Java servlet,using a special JSP compiler.

Enterprise Java Beans (EJB): Used for the standardized, simplified developmentof business applications using Java. They are part of the central elements ofthe Java EE 5 specification.

Java Database Connectivity (JDBC): Uniform interface to databases fromdifferent vendors, defined specifically for relational databases. The tasks ofJDBC include creating and managing database connections, forwarding SQLqueries to the database, and converting the results into a format that is usablefor Java and making them available to the program.

These components reside in different containers of SAP NetWeaver AS Java (seethe figure Containers of SAP NetWeaver AS Java). The containers provide runtimeservices for the application components.



Lesson Summary

You should now be able to: Name the most important managers of the SAP NetWeaver AS Name the most important services of the SAP NetWeaver AS


ADM800 Lesson: Load Balancing in the SAP NetWeaver AS Java Environment

Lesson:37

Load Balancing in the SAP NetWeaver AS JavaEnvironmentLesson Duration: 20 Minutes

Lesson OverviewAn SAP system can be scaled using the number of application servers and the numberof dialog work processes (ABAP) or server processes (Java) for each instance.Requests to the SAP system should be distributed as equally as possible across allapplication servers and processes. A load balancing procedure is required to do this.The techniques used for this in the SAP system are introduced in this lesson.


Explain how load balancing can be realized in the SAP system

In this lesson, the instructor should use the slides to present the different techniquesfor load balancing and discuss their implementation in the SAP system. You canoptionally introduce the SAP Web Dispatcher, which is described in the appendix.Alternatively, direct the participants to SAP customer course ADM102, SAPNetWeaver AS Administration II, in which the SAP Web Dispatcher is discussedin detail.

Business ExampleWith large applications, it is best to spread the load across several components. Loadbalancing is also possible with SAP NetWeaver AS Java.

OverviewIn this section, the different mechanisms for load balancing that are available forSAP NetWeaver AS are presented. You can essentially differentiate between twomechanisms for load balancing:. client-based and server-based load balancing. Ingeneral, we recommend server-based load balancing.



Server-Based Load BalancingA load balancer connected in front acts as a central entry point to the SAP system.This is the case, even if the SAP system is made up of multiple application servers.These technique offers the following advantages:

All application servers can be addressed using a common IP address or acommon name.

The users always use the same URL to access the system. The advantages listed above reduce the operating and maintenance effort and

costs.

This central entry point to the SAP system can be realized using an additionalcomponent, known as a load balancer. As shown in the following figure, this loadbalancer receives inbound requests and distributes these to the application servers.

Figure 15: Server-Based Load Balancing

Client-Based Load BalancingIn addition to SAPs preferred method of server-based load balancing, there are othermethods, which can be preferred in certain circumstances. In particular, if a simpleimplementation of load balancing is desired. With this client-based load balancing,all inbound client requests are initially directed to a central location in the system, aload balancing server, when the connection is first made. The load balancing serverinforms the client which application server it should address. This is illustrated bythe following figure.



Figure 16: Client-Based Load Balancing

Client-based load balancing can be realized using the following mechanisms:

Rerouting the requests using functions -

That provide the HTTP protocol (redirect) That provide the Domain Name System (DNS) protocol, with which the

namespace in the Internet is managed

A simple method of load balancing is already implemented in SAP NetWeaver AS,based on the rerouting of HTTP requests. Their function is shown in the followingfigure.



Figure 17: Load Balancing Using the SAP Message Server

This mechanism functions as follows:

1. The browser sends a request to the message server.2. The message server returns the address of an appropriate application server to

the browser (redirect).3. The browser now sends a request to this application server.4. The user remains connected to this application server for the rest of the duration

of the session.

Although this method is implemented in SAP NetWeaver AS using the messageserver (for AS ABAP or AS ABAP and Java System, this is the ABAP MessageServer; for AS Java, this is the Java Message Server), and is already available afterinstallation, it is not the preferred method due to a number of disadvantages. Some ofthese disadvantages are listed briefly here:

Can lead to confusion of the user, since the URL displayed in the browserchanges with the rerouting

If Favorites are created in the browser, these point to the server to which theuser was rerouted

Can cause problems if a firewall is used



Stateless and Stateful Web ApplicationsThe programming model that underlies the development of Web applications hasan important influence on a load balancer. The programming model differentiatesbetween stateless and stateful Web applications.

The programming model for stateless requests is used for simple applications, forwhich each request to SAP NetWeaver AS is independent of all other requests.

The programming model for stateful requests is used for more complex applications,which are based on a transactional concept. With these applications, informationabout the status of the user session must be stored in the application server.

The mechanism for load balancing in the SAP system must support both stateless andstateful requests. Stateful requests are a particular challenge for the load balancer,since the HTTP protocol only supports stateless requests. This is illustrated in thefollowing figure. The first request is forwarded to an application server by the loadbalancer. If a subsequent request is forwarded to a different application server, this hasno information about the user context.

Figure 18: Stateful Requests

The load balancer must therefore ensure that stateful requests are always forwardedto the same application server. This can be achieved by different implementations inthe load balancer. However, these different techniques are not presented in moredetail here.



Realization of Load Balancing in SAP NetWeaver AS JavaAfter these initial considerations about load balancing, the realization in SAPNetWeaver AS Java is now presented in this section.

Load balancing within SAP NetWeaver AS Java allows the optimal distribution ofthe incoming requests to the available resources. SAP NetWeaver Application Serverprovides load balancing at different levels, as shown in the following figure.

Figure 19: Load balancing in SAP NetWeaver AS Java

In a cluster with multiple SAP NetWeaver AS Java instances, load balancing isperformed using a load balancer connected in front (1). Within the Java instance,the Java dispatcher (2) distributes the inbound requests to the server processes withwhich it is connected.



Load Balancing Between Many Java InstancesThe following figure shows a system with multiple Java instances, for which the SAPWeb Dispatcher is already activated in the DMZ as a load balancer. This performs theload balancing between the Java instances. The ICMs of the instance distributes therequests to their server processes.

Hint: You can also use any other load balancing device instead of the SAPWeb Dispatcher. In this case, you need to register the hosts and ports with it;the communication with the message server does not take place.

Figure 20: Load Balancing Between Many Java Instances

The SAP Web Dispatcher fetches the information that it requires from the messageserver about:

All ICMs with their HTTP ports, to which it can forward requests The capacities of the connected Java instances, so that it can use the weighted

round robin procedure. For this, the SAP Web Dispatcher simply needs, in itsprofile file, the host name and the port at which it can reach the message server(parameter rdisp/mshost,ms/http_port).



The SAP Web Dispatcher is delivered with the message server. In thestandard installation, you will find this, for example, in a subdirectory of/usr/sap//SYS/exe.

The SAP Web Dispatcher can be used for load balancing in the following scenarios:

Java-only scenario, as described here. ABAP-only scenario (see SAP customer training course ADM102,

Administration AS ABAP II) Integrated scenario (Java+ABAP) (see SAP customer training course ADM102,

Administration AS ABAP II)

Appendix: SAP Web DispatcherAs previously described, the SAP Web Dispatcher, which lies between the Internetand the SAP system, can be used as a load balancer. It is the entry point for HTTP(S)requests into your system, which consists of one or more Web application servers.As a "software Web switch", it can reject or accept connections. When it accepts aconnection, it distributes the requests to ensure an even distribution across the servers(load balancing).

Hint: Not only does using the SAP Web Dispatcher allow you to realize loadbalancing across multiple SAP NetWeaver AS instances, it also providessecurity functions (entry point in the DMZ, SSL, URL filtering).

The SAP Web Dispatcher forwards inbound requests (HTTP, HTTPS) to the SAPNetWeaver AS instances of the SAP system in turn, where the number of requests thata SAP Web AS receives is weighted according to its capacity. The capacity of a SAPNetWeaver AS ABAP depends on the number of configured dialog work processes.For SAP NetWeaver AS Java, the capacity is determined by the number of serverprocesses. If the application is stateful, the SAP Web Dispatcher ensures at the nextrequest that the user is again forwarded to the server processing his or her application.It uses the session cookie to do this for HTTP connections, and the client IP address forend-to-end SSL. The SAP Web Dispatcher also decides whether the inbound requestis to be forwarded to a SAP NetWeaver AS ABAP or a SAP NetWeaver AS Java.

Hint: Unlike the HTTP load balancing performed by the SAP message server,no redirect is performed when using the SAP Web Dispatcher. In this way,the associated disadvantages (a large number of IP addresses must be known,bookmarking is not possible, authentication after a change of applicationserver) are also avoided.



The SAP Web Dispatcher is a separate program that can run on a host that is directlyconnected to the Internet. It requires minimal configuration. You only need to enterthe following data in the profile file for the SAP Web Dispatcher:

Port on which the HTTP(S) requests are to be received (parametericm/server_port_)

Host and HTTP port of the SAP message server (parameter rdisp/mshost andparameter ms/http_port)

If you want to be able to call the Web application externally, for example withthe URL http://shop.sap.com, this host name must be mapped internally to theSAP Web Dispatcher. This then forwards the HTTP(S) request to a suitableSAP NetWeaver AS.

Hint: The SAP Web Dispatcher is presented in detail in the SAP customertraining course ADM102, Administration AS ABAP II. For informationabout the change history of the SAP Web Dispatcher, see the composite SAPNote on the SAP Web Dispatcher (SAP Note 538405 and 1093023).



Lesson Summary

You should now be able to: Explain how load balancing can be realized in the SAP system


Unit Summary ADM800

Unit SummaryYou should now be able to: Use basic Java terminology Explain the architecture of SAP NetWeaver Application Server Explain the term Central Services of SAP NetWeaver AS Java Understand and use concepts such as Java instance, ICM, and server Name the most important managers of the SAP NetWeaver AS Name the most important services of the SAP NetWeaver AS Explain how load balancing can be realized in the SAP system


ADM800 Test Your Knowledge

49Test Your Knowledge

1. Which of the programming languages listed below are implementedplatform-independently?Choose the correct answer(s). A Fortran B ABAP C Java D C/C++

2. Briefly describe the function of the Java Virtual Machine (JVM).

3. Which of the software components listed below are components of SAPNetWeaver AS?Choose the correct answer(s). A ABAP Work Processes B Java Message Server C Internet Communication Manager

4. Which software components allow load balancing in the context of SAPNetWeaver AS Java?Choose the correct answer(s). A SAP Web Dispatcher B ABAP Dispatcher C Server processes


Test Your Knowledge ADM800

50Answers

1. Which of the programming languages listed below are implementedplatform-independently?

Answer: B, C

ABAP and Java are programming languages that are implementedplatform-independently.

2. Briefly describe the function of the Java Virtual Machine (JVM).

Answer: The JVM executes the platform-independent bytecode generated bythe Java compiler on the relevant hardware.

3. Which of the software components listed below are components of SAPNetWeaver AS?

Answer: A, B, C

Components of SAP NetWeaver AS: Internet Communication Manager, ABAPdispatcher, ABAP work processes, ABAP message server, Java server processes,Java message server und Java enqueue server.

4. Which software components allow load balancing in the context of SAPNetWeaver AS Java?

Answer: A

The SAP Web Dispatcher distributes inbound requests across multiple SAPNetWeaver AS Java instances.


Unit 253 Starting and Stopping

As an instructor, show the starting and stopping and refer to the differences betweenSAP NetWeaver AS ABAP+Java and SAP NetWeaver AS Java

The process of starting using the Startup and Control Framework is important forsubsequent units. The participants should also be able to find the most important logfiles that are written when starting and stopping.

Unit OverviewThis unit describes the process when starting an SAP NetWeaver AS Java. SAPNetWeaver AS Java uses the Startup and Control Framework to perform the startprocess of the Java instances. On all operating systems, it is possible to use the SAPManagement Console for starting and stopping. In the Windows operating system, itis also possible to use the Microsoft Management Console (SAP MMC). In the UNIXoperating system, it is also possible to use the startsap and stopsap scripts. Finally,the log and trace files of the start/stop process are listed.

Unit ObjectivesAfter completing this unit, you will be able to:

Describe the sequence in which the components of an SAP system and startedand stopped

Describe the general start process for an SAP NetWeaver AS Java Describe the general start process for an SAP NetWeaver AS ABAP + Java Operate the tools to start and stop SAP NetWeaver AS ABAP + Java Operate the tools to start and stop SAP NetWeaver AS Java Use the term Startup and Control Framework Describe the individual steps during the start and stop processes of a Java

instance


Unit 2: Starting and Stopping ADM800

Find the storage locations of trace and log files of the Startup and ControlFramework.

Name the most important trace and log files of the Startup and ControlFramework and review their content.

Unit ContentsLesson: Overview of the Process for Starting and Stopping an SAPNetWeaver AS Java ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61Lesson: Tools for Starting and Stopping ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Exercise 1: Tools for Starting and Stopping... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Lesson: Java Startup and Control Framework... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Exercise 2: Java Startup and Control Framework ... . . . . . . . . . . . . . . . . . . . . . . . 97Lesson: Logs of the Start and Stop Processes of SAP NetWeaver AS Java 100

Exercise 3: Logs of the Start and Stop Processes of SAP NetWeaver ASJava ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105


ADM800 Lesson: Overview of the Process for Starting and Stopping an SAP NetWeaver AS Java

Lesson:55

Overview of the Process for Starting and Stopping anSAP NetWeaver AS JavaLesson Duration: 20 Minutes

Lesson OverviewT

adm800 - administration as java 7.1(col74)

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