DTrace

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