1. Chapter 1 Introduction

   1. Web Caching

   2. A Brief History of Squid

   3. Hardware and Operating System Requirements

   4. Squid Is Open Source

   5. Squid's Home on the Web

   6. Getting Help

   7. Getting Started with Squid

   8. Exercises

2. Chapter 2 Getting Squid

   1. Versions and Releases

   2. Use the Source, Luke

   3. Precompiled Binaries

   4. Anonymous CVS

   5. devel.squid-cache.org

   6. Exercises

3. Chapter 3 Compiling and Installing

   1. Before You Start

   2. Unpacking the Source

   3. Pretuning Your Kernel

   4. The configure Script

   5. make

   6. make Install

   7. Applying a Patch

   8. Running configure Later

   9. Exercises

4. Chapter 4 Configuration Guide for the Eager

   1. The squid.conf Syntax

   2. User IDs

   3. Port Numbers

   4. Log File Pathnames

   5. Access Controls

   6. Visible Hostname

   7. Administrative Contact Information

   8. Next Steps

   9. Exercises

5. Chapter 5 Running Squid

   1. Squid Command-Line Options

   2. Check Your Configuration File for Errors

   3. Initializing Cache Directories

   4. Testing Squid in a Terminal Window

   5. Running Squid as a Daemon Process

   6. Boot Scripts

   7. A chroot Environment

   8. Stopping Squid

   9. Reconfiguring a Running Squid Process

   10. Rotating the Log Files

   11. Exercises

6. Chapter 6 All About Access Controls

   1. Access Control Elements

   2. Access Control Rules

   3. Common Scenarios

   4. Testing Access Controls

   5. Exercises

7. Chapter 7 Disk Cache Basics

   1. The cache_dir Directive

   2. Disk Space Watermarks

   3. Object Size Limits

   4. Allocating Objects to Cache Directories

   5. Replacement Policies

   6. Removing Cached Objects

   7. refresh_pattern

   8. Exercises

8. Chapter 8 Advanced Disk Cache Topics

   1. Do I Have a Disk I/O Bottleneck?

   2. Filesystem Tuning Options

   3. Alternative Filesystems

   4. The aufs Storage Scheme

   5. The diskd Storage Scheme

   6. The coss Storage Scheme

   7. The null Storage Scheme

   8. Which Is Best for Me?

   9. Exercises

9. Chapter 9 Interception Caching

   1. How It Works

   2. Why (Not) Intercept?

   3. The Network Device

   4. Operating System Tweaks

   5. Configure Squid

   6. Debugging Problems

   7. Exercises

10. Chapter 10 Talking to Other Squids

    1. Some Terminology

    2. Why (Not) Use a Hierarchy?

    3. Telling Squid About Your Neighbors

    4. Restricting Requests to Neighbors

    5. The Network Measurement Database

    6. Internet Cache Protocol

    7. Cache Digests

    8. Hypertext Caching Protocol

    9. Cache Array Routing Protocol

    10. Putting It All Together

    11. How Do I ...

    12. Exercises

11. Chapter 11 Redirectors

    1. The Redirector Interface

    2. Some Sample Redirectors

    3. The Redirector Pool

    4. Configuring Squid

    5. Popular Redirectors

    6. Exercises

12. Chapter 12 Authentication Helpers

    1. Configuring Squid

    2. HTTP Basic Authentication

    3. HTTP Digest Authentication

    4. Microsoft NTLM Authentication

    5. External ACLs

    6. Exercises

13. Chapter 13 Log Files

    1. cache.log

    2. access.log

    3. store.log

    4. referer.log

    5. useragent.log

    6. swap.state

    7. Rotating the Log Files

    8. Privacy and Security

    9. Exercises

14. Chapter 14 Monitoring Squid

    1. cache.log Warnings

    2. The Cache Manager

    3. Using SNMP

    4. Exercises

15. Chapter 15 Server Accelerator Mode

    1. Overview

    2. Configuring Squid

    3. Gee, That Was Confusing!

    4. Access Controls

    5. Content Negotiation

    6. Gotchas

    7. Exercises

16. Chapter 16 Debugging and Troubleshooting

    1. Some Common Problems

    2. Debugging via cache.log

    3. Core Dumps, Assertions, and Stack Traces

    4. Replicating Problems

    5. Reporting a Bug

    6. Exercises

1. Appendix A Config File Reference

2. Appendix B The Memory Cache

3. Appendix C Delay Pools

   1. Overview

   2. Configuring Squid

   3. Examples

   4. Issues

   5. Monitoring Delay Pools

4. Appendix D Filesystem Performance Benchmarks

   1. The Benchmark Environment

   2. General Comments

   3. Linux

   4. FreeBSD

   5. OpenBSD

   6. NetBSD

   7. Solaris

   8. Number of Disk Spindles

5. Appendix E Squid on Windows

   1. Cygwin

   2. SquidNT

6. Appendix F Configuring Squid Clients

   1. Manually

   2. Proxy Auto-Configuration

   3. WPAD

   4. Summary

7. Colophon

Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects. The animal on the cover of Squid: The Definitive Guide is a giant squid (Architeuthis dux). Of the class Cephalopoda, which means "head foot," the giant squid holds much fascination for humans, part of which has to do with the fact that it has never been observed alive in its natural habitat. Scientists have only been able to study specimens that have been caught or found washed up on beaches. This invertebrate can grow to 60 feet in length and weigh as much as a ton. It's a deep-sea dweller (660-2,300 feet) that is found throughout the world's oceans.

A giant squid consists of seven parts. Its head houses a complex brain. Its eyes are the largest in the animal kingdom--up to 10 inches in diameter. (Most deep-sea animals have very large eyes so they can gather the small amounts of light available in the depths of the ocean.) Its fins are relatively small and help it to balance and maneuver as it swims. Its main body is called a mantle: it's a muscular sac that contains most of the organ systems. Its eight arms are studded with two rows of suckers; it also has two much longer feeding tentacles, the ends of which also have suckers and are called clubs. Finally, its funnel is a multipurpose tube used to breathe, squirt ink, lay eggs, expel waste, and propel itself.

To eat, a giant squid captures its prey with its two long feeding tentacles. Holding the intended dinner with its shorter arms, its sharp horny beak cuts the food up, and a file-like radula sends it down the throat and esophagus; the food then passes directly through the brain to the stomach. Scientists believe giant squid may be solitary hunters because no more than one has ever been caught in the same fishing net. Mary Anne Weeks Mayo was the production editor and copyeditor for Squid: The Definitive Guide. Sada Preisch proofread the book, and Marlowe Shaeffer and Claire Cloutier provided quality control. Jamie Peppard and Mary Agner provided production assistance. Johnna Dinse wrote the index.

Ellie Volckhausen designed the cover of this book, based on a series design by Edie Freedman. The cover image is a 19th-century engraving from the Dover Pictorial Archive. Emma Colby produced the cover layout with QuarkXPress 4.1 using Adobe's ITC Garamond font.

Melanie Wang designed the interior layout, based on a series design by David Futato. This book was converted by Joe Wizda to FrameMaker 5.5.6 with a format conversion tool created by Erik Ray, Jason McIntosh, Neil Walls, and Mike Sierra that uses Perl and XML technologies. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont's TheSans Mono Condensed. The illustrations that appear in the book were produced by Robert Romano and Jessamyn Read using Macromedia FreeHand 9 and Adobe Photoshop 6. The tip and warning icons were drawn by Christopher Bing. This colophon was compiled by Mary Anne Weeks Mayo.