The Oracle Solaris DTrace feature revolutionizes the way you debug operating systems and applications. Using DTrace, you can dynamically instrument software and quickly answer virtually any question about its behavior. Now, for the first time, there's a comprehensive, authoritative guide to making the most of DTrace in any supported UNIX environment--from Oracle Solaris to OpenSolaris, Mac OS X, and FreeBSD.

Written by key contributors to the DTrace community, DTrace teaches by example, presenting scores of commands and easy-to-adapt, downloadable D scripts. These concise examples generate answers to real and useful questions, and serve as a starting point for building more complex scripts. Using them, you can start making practical use of DTrace immediately, whether you're an administrator, developer, analyst, architect, or support professional.

The authors fully explain the goals, techniques, and output associated with each script or command. Drawing on their extensive experience, they provide strategy suggestions, checklists, and functional diagrams, as well as a chapter of advanced tips and tricks. You'll learn how to

• Write effective scripts using DTrace's D language

• Use DTrace to thoroughly understand system performance

• Expose functional areas of the operating system, including I/O, filesystems, and protocols

• Use DTrace in the application and database development process

• Identify and fix security problems with DTrace

• Analyze the operating system kernel

• Integrate DTrace into source code

• Extend DTrace with other tools

  This book will help you make the most of DTrace to solve problems more quickly and efficiently, and build systems that work faster and more reliably.

  Autorentext

  Brendan Gregg is a performance specialist at Joyent and is known worldwide in the field of DTrace. Brendan created and developed the DTraceToolkit and is the coauthor of SolarisTM Performance and Tools (Prentice Hall, 2006) as well as numerous articles about DTrace. Many of Brendan's DTrace scripts are shipped by default in Mac OS X.

  Jim Mauro is a senior software engineer for Oracle Corporation, working in the Systems group with a primary focus on systems performance. Jim has 30 years of experience in the computer industry and coauthored SolarisTM Performance and Tools and the first and second editions of SolarisTM Internals (Sun Microsystems Press, 2000, and Prentice Hall, 2006).

  Inhalt

  Foreword xxi

  Preface xxv

  Acknowledgments xxxi

  About the Authors xxxv

  Part I: Introduction

  Chapter 1: Introduction to DTrace 1

  What Is DTrace? 1

  Why Do You Need It? 1

  Capabilities 2

  Dynamic and Static Probes 4

  DTrace Features 4

  A First Look 6

  Overview 8

  Architecture 16

  Summary 17

  Chapter 2: D Language 19

  D Language Components 20

  Probes 23

  Variables 26

  Aggregations 33

  Actions 37

  Options 43

  Example Programs 44

  Summary 49

  Part II: Using DTrace

  Chapter 3: System View 51

  Start at the Beginning 52

  Observing CPUs 56

  Observing Memory 95

  Observing Disk and Network I/O 125

  Summary 148

  Chapter 4: Disk I/O 151

  Capabilities 152

  Disk I/O Strategy 154

  Checklist 155

  Providers 156

  Scripts 172

  Case Studies 269

  Summary 290

  Chapter 5: File Systems 291

  Capabilities 292

  Strategy 295

  Checklist 296

  Providers 297

  Scripts 313

  Case Study 387

  Summary 397

  Chapter 6: Network Lower-Level Protocols 399

  Capabilities 400

  Strategy 402

  Checklist 403

  Providers 404

  Scripts 445

  Common Mistakes 548

  Summary 555

  Chapter 7: Application-Level Protocols 557

  Capabilities 558

  Strategy 558

  Checklist 559

  Providers 560

  Scripts 574

  Summary 668

  Chapter 8: Languages 669

  Capabilities 671

  Strategy 672

  Checklist 674

  Providers 675

  C 679

  C++ 689

  Java 691

  JavaScript 705

  Perl 719

  PHP 731

  Python 740

  Ruby 751

  Shell 764

  Tcl 774

  Summary 782

  Chapter 9: Applications 783

  Capabilities 784

  Strategy 784

  Checklist 786

  Providers 787

  Scripts 804

  Case Studies 817

  Summary 832

  Chapter 10: Databases 833

  Capabilities 834

  Strategy 835

  Providers 836

  MySQL 837

  PostgreSQL 851

  Oracle 858

  Summary 865

  Part III: Additional User Topics

  Chapter 11: Security 867

  Privileges, Detection, and Debugging 867

  Scripts 875

  Summary 892

  Chapter 12: Kernel 893

  Capabilities 894

  Strategy 896

  Checklist 897

  Providers 897

  Scripts 932

  Summary 945

  Chapter 13: Tools 947

  The DTraceToolkit 948

  Chime 962

  DTrace GUI Plug-in for NetBeans and Sun Studio 966

  DLight, Oracle Solaris Studio 12.2 966

  Mac OS X Instruments 971

  Analytics 973

  Summary 985

  Chapter 14: Tips and Tricks 987

  Tip 1: Known Workloads 987

  Tip 2: Write Target Software 989

  Tip 3: Use grep to Search for Probes 991

  Tip 4: Frequency Count 991

  Tip 5: Time Stamp Column, Postsort 992

  Tip 6: Use Perl to Postprocess 993

  Tip 7: Learn Syscalls 994

  Tip 8: timestamp vs. vtimestamp 995

  Tip 9: profile:::profile-997 and Profiling 996

  Tip 10: Variable Scope and Use 997

  Tip 11: strlen() and strcmp() 999

  Tip 12: Check Assumptions 1000

  Tip 13: Keep It Simple 1001

  Tip 14: Consider Performance Impact 1001

  Tip 15: drops and dynvardrops 1003

  Tip 16: Tail-Call Optimization 1003

  Further Reading 1003

  Appendix A: DTrace Tunable Variables 1005

  Appendix B: D Language Reference 1011

  Appendix C: Provider Arguments Reference 1025

  Providers 1025

  Arguments 1038

  Appendix D: DTrace on FreeBSD 1045

  Enabling DTrace on FreeBSD 7.1 and 8.0 1045

  DTrace for FreeBSD: John Birrell 1047

  Appendix E: USDT Example 1051

  USDT Bourne Shell Provider 1052

  Case Study: Implementing a Bourne Shell Provider 1057

  Appendix F: DTrace Error Messages 1063

  Privileges 1063

  Drops 1064

  Aggregation Drops 1065

  Dynamic Variable Drops 1066

  Invalid Address 1066

  Maximum Program Size 1067

  Not Enough Space 1068

  Appendix G: DTrace Cheat Sheet 1069

  Synopsis 1069

  Finding Probes 1069

  Finding Probe Arguments 1070

  Probes 1070

  Vars 1070

  Actions 1071

  Switches 1071

  Pragmas 1071

  One-Liners 1072

  Bibliography 1073

  Suggested Reading 1073

  Vendor Manuals 1075

  Index 1089