Java Stand-alone Applications on z/OS Volume 1 - IBM Redbooks

244 Pages·2006·5.99 MB·English

Front cover

Java Stand-alone

Applications on z/OS
Volume 1
Setting up an environment for
managing Java programs on z/OS
Building, deploying, running, and
debugging applications
Analyzing application
performance and
exploiting zAAP
Alex Louwe Kooijmans

Paul Anderson
Kenichi Yoshimura
Linfeng Yu
ibm.com/redbooks

International Technical Support Organization

Java Stand-alone Applications on z/OS
Volume 1
May 2006

SG24-7177-00
Note: Before using this information and the product it supports, read the information in
“Notices” on pagevii.

First Edition (May 2006)
This edition applies to IBM SDK for z/OS, Java 2 Technology Edition, productnumber 5655-I56.
© Copyright International Business Machines Corporation 2006. All rights reserved.
Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP
Schedule Contract with IBM Corp.
Contents

Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .viii
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ix
The team that wrote this redbook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
Become a published author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xi
Comments welcome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xi
Chapter 1. Scenarios for running Java stand-alone applications on z/OS 1
1.1 Definition of Java stand-alone applications. . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.1 Definition of batch applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Legacy system modernization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Reasons to use Java for stand-alone applications . . . . . . . . . . . . . . . . . . . 5
1.3.1 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3.2 XML processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3.3 Reusing J2EE online program logic . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.4 Migrating Java applications for QoS and server consolidation. . . . . . 7
1.3.5 Availability of skill set for the future. . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.6 zAAP processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Topologies of Java stand-alone applications . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 2. Job management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1 The first Java program on z/OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2 Running a Java program as a batch job . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.1 Overview of Job Control Language. . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.2 Writing JCL for a Java batch job. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.3 Limitations of BPXBATCH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.2.4 BPXBATSL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.5 Comparison of JCLBATCH and JCLBATSL. . . . . . . . . . . . . . . . . . . 22
2.3 Developing multi-step jobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.1 Specifying multiple steps in a JCL script. . . . . . . . . . . . . . . . . . . . . . 23
2.3.2 Conditions on a step. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.3.3 Conditional step execution using IF-ELSE . . . . . . . . . . . . . . . . . . . . 26
2.4 Design considerations for multi-step jobs . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.4.1 What skill sets are available in the development team?. . . . . . . . . . 27

2.4.2 How much integration with legacy applications is necessary? . . . . . 27
2.4.3 How much control is required between steps?. . . . . . . . . . . . . . . . . 27
2.4.4 Return code from BPXBATCH and BPXBATSL. . . . . . . . . . . . . . . . 28
© Copyright IBM Corp. 2006. All rights reserved. iii
Chapter 3. Access to MVS data sets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.1 The JRIO library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.1.1 JRIO classes and interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3.1.2 JRIO usage examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2 Working with VSAM data sets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2.1 VSAM overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2.2 Accessing records in a VSAM data set using the JRIO library. . . . . 42
3.3 Working with COBOL packed decimal numbers. . . . . . . . . . . . . . . . . . . . 46
3.3.1 Converting from COBOL packed decimals to Java integers. . . . . . . 48
3.3.2 Converting from Java integers to COBOL packed decimals. . . . . . . 49
3.4 JRecord bean generator and supporting APIs . . . . . . . . . . . . . . . . . . . . . 50
3.4.1 JRecord utility APIs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.4.2 Generating a Java bean for a record . . . . . . . . . . . . . . . . . . . . . . . . 50
3.4.3 JRecord runtime library and plug-in installation . . . . . . . . . . . . . . . . 60
Chapter 4. Tools and techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2 Application build and deployment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2.1 Ant support in Eclipse. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2.2 Set up Ant ftp support in Eclipse. . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.2.3 Build and deployment Ant script . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.2.4 Use the ANT buildfile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4.2.5 Further discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.3 Debugging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.3.1 Remote debugging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.3.2 Preparing the Java program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.3.3 Creating a shell script and JCL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
4.3.4 Deploying and starting a Java application. . . . . . . . . . . . . . . . . . . . . 78
4.3.5 Work with the debugger in the Eclipse workbench. . . . . . . . . . . . . . 82
4.3.6 Local debugging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.3.7 Rational Application Developer considerations. . . . . . . . . . . . . . . . . 90
Chapter 5. Measuring performance and application profiling . . . . . . . . . 91
5.1 Performance analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
5.1.1 Tooling overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
5.1.2 Establishing a goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
5.2 Overview of analysis strategies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.2.1 Statistical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.2.2 Fractional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.2.3 Elimination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
5.2.4 Accurate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
5.3 Statistical analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
5.4 Fractional analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
iv Java Stand-alone Applications on z/OS Volume 1
5.4.1 TIMEUSED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
5.5 Elimination analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
5.6 Accurate analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

5.6.1 Installing TPTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.6.2 Profiling an application on z/OS . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
5.6.3 Fractional analysis with TPTP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
5.7 Code listings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Chapter 6. Exploiting zAAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
6.1 zAAP prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
6.2 Overview of zAAP and runtime options. . . . . . . . . . . . . . . . . . . . . . . . . . 174
6.3 Exploring zAAP utilization potentials. . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
6.3.1 zAAP utilization estimate and projection tool . . . . . . . . . . . . . . . . . 175
6.3.2 Experimental results of zAAP utilization estimates. . . . . . . . . . . . . 178
6.3.3 Hardware and software configuration. . . . . . . . . . . . . . . . . . . . . . . 181
Chapter 7. Problem determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
7.2 Checking the z/OS environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
7.2.1 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
7.2.2 LE settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
7.2.3 Environment variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
7.2.4 Private storage usage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
7.2.5 Service Class for the application. . . . . . . . . . . . . . . . . . . . . . . . . . . 186
7.3 Collecting data for problem determination. . . . . . . . . . . . . . . . . . . . . . . . 187
7.3.1 JVM dump control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
7.3.2 CEEDUMP, SYSTDUMP and SVCDUMP . . . . . . . . . . . . . . . . . . . 189
7.3.3 JAVADUMP and HEAPDUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
7.3.4 Other problem determination data . . . . . . . . . . . . . . . . . . . . . . . . . 192
7.4 Dump analysis and tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
7.4.1 Analyzing SYSTDUMP and SVCDUMP . . . . . . . . . . . . . . . . . . . . . 194
7.4.2 Interpreting a JAVADUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
7.4.3 HeapAnalyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
7.4.4 Other analysis tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7.5 Problem determination scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7.5.1 Diagnose crashes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7.5.2 Debugging hangs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7.5.3 Debugging memory leaks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7.5.4 Debugging performance problems . . . . . . . . . . . . . . . . . . . . . . . . . 215

Appendix A. Additional material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Locating the Web material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Using the Web material. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
System requirements for downloading the Web material . . . . . . . . . . . . . 218
Contents v
Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Other publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

Online resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
How to get IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Help from IBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

vi Java Stand-alone Applications on z/OS Volume 1
Notices

This information was developed for products and services offered in the U.S.A.
IBM may not offer the products, services, or features discussed in this document in other countries. Consult
your local IBM representative for information on the products and services currently available in your area.
Any reference to an IBM product, program, or service is not intended to state or imply that only that IBM
product, program, or service may be used. Any functionally equivalent product, program, or service that
does not infringe any IBM intellectual property right may be used instead. However, it is the user's
responsibility to evaluate and verify the operation of any non-IBM product, program, or service.
IBM may have patents or pending patent applications covering subject matter described in this document.
The furnishing of this document does not give you any license to these patents. You can send license
inquiries, in writing, to:
IBM Director of Licensing, IBM Corporation, North Castle Drive Armonk, NY 10504-1785 U.S.A.
The following paragraph does not apply to the United Kingdom or any other country where such provisions
are inconsistent with local law: INTERNATIONAL BUSINESS MACHINES CORPORATION PROVIDES
THIS PUBLICATION "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-INFRINGEMENT,
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow disclaimer
of express or implied warranties in certain transactions, therefore, this statement may not apply to you.
This information could include technical inaccuracies or typographical errors. Changes are periodically made
to the information herein; these changes will be incorporated in new editions of the publication. IBM may
make improvements and/or changes in the product(s) and/or the program(s) described in this publication at
any time without notice.
Any references in this information to non-IBM Web sites are provided for convenience only and do not in any
manner serve as an endorsement of those Web sites. The materials at those Web sites are not part of the
materials for this IBM product and use of those Web sites is at your own risk.
IBM may use or distribute any of the information you supply in any way it believes appropriate without
incurring any obligation to you.
Information concerning non-IBM products was obtained from the suppliers of those products, their published
announcements or other publicly available sources. IBM has not tested those products and cannot confirm
the accuracy of performance, compatibility or any other claims related to non-IBM products. Questions on
the capabilities of non-IBM products should be addressed to the suppliers of those products.
This information contains examples of data and reports used in daily business operations. To illustrate them
as completely as possible, the examples include the names of individuals, companies, brands, and products.
All of these names are fictitious and any similarity to the names and addresses used by an actual business
enterprise is entirely coincidental.
COPYRIGHT LICENSE:
This information contains sample application programs in source language, which illustrates programming
techniques on various operating platforms. You may copy, modify, and distribute these sample programs in
any form without payment to IBM, for the purposes of developing, using, marketing or distributing application

programs conforming to the application programming interface for the operating platform for which the
sample programs are written. These examples have not been thoroughly tested under all conditions. IBM,
therefore, cannot guarantee or imply reliability, serviceability, or function of these programs. You may copy,
modify, and distribute these sample programs in any form without payment to IBM for the purposes of
developing, using, marketing, or distributing application programs conforming to IBM's application
programming interfaces.
© Copyright IBM Corp. 2006. All rights reserved. vii
Trademarks

The following terms are trademarks of the International Business Machines Corporation in the United States,
other countries, or both:
Es erver® DB2 Connect™ Redbooks™
Eserver® DB2® RACF®
Redbooks (logo) ™ Iterations® System z™
eServer™ IBM® System z9™
z/OS® IMS™ VisualAge®
zSeries® Language Environment® WebSphere®
z9™ MVS™
CICS® Rational®
The following terms are trademarks of other companies:
Enterprise JavaBeans, EJB, Java, JavaBeans, JDBC, JDK, JVM, J2EE, and all Java-based trademarks are
trademarks of Sun Microsystems, Inc. in the United States, other countries, or both.
Excel, Microsoft, Windows, and the Windows logo are trademarks of Microsoft Corporation in the United
States, other countries, or both.
UNIX is a registered trademark of The Open Group in the United States and other countries.
Linux is a trademark of Linus Torvalds in the United States, other countries, or both.
Other company, product, or service names may be trademarks or service marks of others.

viii Java Stand-alone Applications on z/OS Volume 1