Front cover Maximum Performance with WebSphere Application Server V5.1 on iSeries The most complete book on WebSphere Application Server on iSeries performance tuning End-to-end performance tuning methodology Several good and practical examples Luis Aused Maggie Biggs Andreas Hagger Chris Larsen Elena Lowery Aleksandr Nartovich Petri Nuutinen ibm.com/redbooks International Technical Support Organization Maximum Performance with WebSphere Application Server V5.1 on iSeries January 2005 SG24-6383-00 Note: Before using this information and the product it supports, read the information in “Notices” on page ix. First Edition (January 2005) This edition applies to Version 5, Release 1 of WebSphere Application Server on iSeries (5733-W51). © Copyright International Business Machines Corporation 2005. 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 . ix Trademarks . .x Preface . xi The team that wrote this redbook. xi Become a published author . xiii Comments welcome. xiii Chapter 1. Performance concepts and factors. 1 1.1 Topology . 2 1.2 Client considerations. 4 1.3 Network design . 5 1.4 Maximizing server performance . 6 1.5 Performance and emerging architectures . 8 1.5.1 Service-oriented architectures . 8 1.5.2 Virtualization . 9 Chapter 2. Java and WebSphere execution environment on iSeries servers . 11 2.1 Java execution environment . 12 2.1.1 Java virtual machine implementation . 12 2.1.2 Java Runtime Environment. 12 2.2 Java compilation environment. 12 2.2.1 Direct execution using Java transformation . 13 2.2.2 JIT compiler . 13 2.2.3 Compiling and running Java code. 14 2.3 Garbage collection . 15 2.3.1 Basics in collecting garbage . 15 2.3.2 Garbage collection pitfalls. 16 2.4 Profiling (PFRDTA) . 16 2.4.1 Profiling on the iSeries . 16 2.4.2 Collecting profiling data. 16 2.5 IBM Toolbox for Java . 17 2.6 WebSphere execution environment . 17 2.6.1 Administration . 18 2.6.2 Application development. 18 2.6.3 Security . 19 2.6.4 Web services . 20 Chapter 3. Performance tuning methodology . 21 3.1 Setting performance objectives. 22 3.2 General tuning process and performance strategy . 23 3.3 Performance problem determination process . 24 3.4 Summary of key performance measurement tools . 25 Chapter 4. Tools for determining performance problems . 27 4.1 System-level tools . 28 4.2 System-level tools for real time use . 28 4.2.1 WRKSYSSTS command. 28 4.2.2 WRKDSKSTS command. 29 © Copyright IBM Corp. 2005. All rights reserved. iii 4.2.3 WRKACTJOB command. 31 4.2.4 WRKSYSACT command. 35 4.2.5 Management Central . 36 4.2.6 iDoctor. 40 4.2.7 HEAPANA command . 81 4.2.8 Database Monitor for iSeries. 85 4.2.9 Identifying and tuning problem areas . 91 4.2.10 SQL Visual Explain . 91 4.3 System-level tools for reactive use . 93 4.3.1 Collecting performance data . 93 4.3.2 Creating performance data . 96 4.3.3 Performance Tools for iSeries. 98 4.3.4 Using the system performance tools. 99 4.3.5 Performance Management for iSeries, PM/400, and PM eServer iSeries . 100 4.4 Java and application-level tools . 101 4.4.1 DMPJVM command . 101 4.4.2 ANZJVM command. 102 4.4.3 JAVAGCTOOLS (STRSST) . 106 4.5 WebSphere performance tools . 116 4.5.1 Profiling applications running on the WebSphere Application Server. 117 4.5.2 Performance Monitoring Infrastructure . 128 4.5.3 Tivoli Performance Viewer . 130 4.5.4 Performance Advisors. 132 4.5.5 Log Analyzer . 142 4.6 HTTP performance tools . 145 4.6.1 Server logging. 146 4.6.2 HTTP server tracing . 149 4.6.3 Collection Services . 152 4.6.4 Communications trace . ..