- Table of Contents
- Web Performance Tuning, 2nd Edition
- Preface
- I. Preliminary Considerations
- 1. The Quick and the Dead
- Questions for the Browser Side
- Is Your Modem On?
- Is Your Modem Connected to Your Computer?
- Did the Other End Hang Up on You?
- Are You Sending Data over the Modem?
- Do You Have a Valid IP Address and Gateway Router?
- Is the Browser Hanging?
- Is Your Browser in “Offline” Mode?
- Can You Still Resolve Names?
- Is an Intermediate Router Down or Very Slow?
- Is the Remote Site Overloaded?
- Is the Remote Site Down?
- Is There a Mirror Site?
- Did You Already Get Most of the Page?
- Is Your MTU too Big, or too Small?
- Do You Need to Use a Proxy Server?
- Does Your Proxy Handle https URLs?
- Is There a Faster Proxy Server?
- Are You Being Blocked Deliberately?
- Are You Running too Many Programs?
- Do You Have Enough Memory?
- Is Your CPU Fast Enough?
- Do You Have Enough Bandwidth?
- Are Excessive Images Dragging Down Your Performance?
- Is Browser Startup Time Getting You Down?
- Are You Using a Slow Browser?
- Is Your Cache Big Enough?
- Are You Wasting Time Verifying Cached Pages?
- Is Java Startup Time Annoying You?
- Could You Benefit from Using a Specific ISP?
- Are You Surfing at Slow Times?
- Could Your Organization Benefit by Installing a Proxy Server?
- Questions for the Server Side
- Is Your Server Sleeping?
- Is Your DNS Server Overloaded?
- Do Your Images All Have Sizes and ALT Tags?
- Do All Your Applets Have ALT Tags?
- Are There Needless or Slow Redirects?
- Is Your Web Server Wasting Time on Reverse DNS Lookups?
- Is Your Web Server Retransmitting too Much?
- Are You too Far Away from Your Users?
- Is Your Server Network Connection Overloaded?
- Is Your Server CPU-Bound?
- Are You Short of Memory?
- Are Your Disks too Busy?
- Could You Benefit from Caching Services?
- Are You Suffering from Performance Bugs That Have Already Been Fixed?
- Is cron Killing Performance at Regular Intervals?
- Is Your Web Site Being Crowded by Other Processes?
- Are You Wasting Time with SSIs?
- Is Your Content Unncessarily Dynamic?
- Is Your Database Connection Pool too Small?
- Is Your Database Connection Pool Leaking?
- Are Your Hubs, Switches, and Routers Overloaded or Misconfigured?
- Do Java Processes Suddenly Stall?
- Are You Using CORBA, EJBs, or RMI?
- Are You Doing Excessive Logging?
- Are You Serving Content Directly from a Revision Control System?
- The Server Is Not at All Busy, but It’s Slow!
- Key Recommendations
- Questions for the Browser Side
- 2. Web Site Architecture
- 3. Capacity Planning
- Do the Math . . .
- . . . But Trust Your Eyes More than the Math
- Questions to Ask
- How Many HTTP Operations per Unit Time Do You Expect?
- What Is the Purpose of the Web Site?
- How Tolerant Are Your Users?
- Will You Provide Any Streaming Media?
- Will the Web Server Spawn Additional Processes?
- What Other Processes Need to Run on the Web Server or over the Network?
- What Sort of Scalability Do You Need?
- What Is Your Budget?
- How Available Does Your Site Have to Be?
- Can You Force Suppliers to Compete?
- Hey Kid, Want to Try a Browser?
- Other Questions
- How Much Bandwidth Do You Need?
- How Fast a Server Do You Need?
- How Much Memory Do You Need?
- Key Recommendations
- 4. Performance Monitoring
- Parameters of Performance
- Latency and Throughput
- Utilization
- Efficiency
- Monitoring Web Performance Using Perl
- Automatically Generating Monitoring Scripts Using Sprocket
- Using a Relational Database to Store and Retrieve Your Monitoring Data
- Monitoring Machine Utilization with rstat
- Monitoring Per-Process Statistics
- Generating Graphs from ps Data
- Monitoring Other Things
- Making a System Dashboard Web Page
- Key Recommendations
- 5. Load Testing
- 6. Performance Analysis
- 7. Reliability
- Typical Failures
- Disk Full
- Process Out of File Descriptors
- C Pointer Error
- Memory Leaks
- Thread Deadlock
- Dead Process Holding Lock
- Server Overloaded
- Load Balancer Fails to Detect Dead Machine
- Subnet Flooded
- Out of ptys
- Database Out of Cursors
- Bad Device Driver
- Hardware Failures
- Power Outage
- Administrator on Wrong Server
- Wildcards Including Wrong File
- Permissions Problems
- Path Problems
- Patch Problems
- Cascade of Overloads
- Monitoring Causing Failures
- Retries Cause Further Failures
- Critical Tables Locked by Accident
- Using a Database Where Files Will Do
- Program Fails to Reconnect to Database After Failure
- Program Fails to Restart After Reboot
- Split-Brain Syndrome
- Firewall “Cleanup” Blocks Essential Service
- Screen Scraping Fails Because of Design Change
- Dependencies
- Smoothing Outages
- Key Recommendations
- Typical Failures
- 8. Security
- 9. Case Studies
- 10. Principles and Patterns
- Principles of Performance Tuning
- Sometimes You Lose
- To Measure Something Is to Change It
- Reading Is Fundamental
- There Is No Free Lunch
- Returns Diminish
- Portability Will Reduce Performance
- Increasing Abstraction Will Reduce Performance
- Security Will Reduce Performance
- Memory Is Hierarchical
- Caches Depend on Locality of Reference
- I/O Is Slow
- Information Is Relative
- Hardware Is Cheap, Software Is Expensive
- The Goal of Tuning Is Simultaneous Failure
- Better Is Relative
- Bits Are Cost
- Internet Performance Degrades Nonlinearly
- Tuning at the Highest Level Gives the Biggest Gains
- Whatever Occurs Once Is Likely to Happen Again Soon
- The 80/20 Rule
- It’s Not What You Know, It’s Whom You Know
- Patterns of Performance Improvement
- Key Recommendations
- Principles of Performance Tuning
- 1. The Quick and the Dead
- II. Tuning in Depth
- 11. Browsers
- 12. Client Operating System
- 13. Client Hardware
- 14. Lines and Terminators
- 15. Network Protocols
- 16. Server Hardware
- 17. Server Operating System
- Unix and the Origin of the Web
- Unix Flavors
- System Calls Versus Library Calls
- Processes and the Kernel
- The Filesystem
- The Windowing System
- Versions and Patches
- Configurable OS Parameters
- Unix OS Monitoring Tools
- System Call Tracers
- Network Snooping Tools
- How Many Connections Can My Server Handle?
- How Many Processes Can My Server Handle?
- How Quickly Can My Server Fork New Processes?
- Unix Versus NT as the Web Server OS
- The Exokernel
- Key Recommendations
- 18. Server Software
- 19. Content
- 20. Custom Applications
- Programmers
- CGI Programs
- CGI Internals and Performance Problems
- General CGI Tips
- CGI Language-Specific Optimization Tips
- Daemonize It
- CGI Database Access Performance
- Logging
- NSAPI and ISAPI
- DOM
- JSP, ASP, PHP
- Key Recommendations
- 21. Java
- Java Will Never Be Good Enough for GUI Applications
- Java Is Good Enough for the Server Side
- Performance Problems Intrinsic to Java
- Coding Tips
- Use Good Algorithms
- Keep Short Inheritance Chains
- Use Stack Variables
- Merge Classes
- Use Java Libraries
- Do Not Poll
- Finalize Methods
- Create Fewer Objects
- Beware of Object Leaks
- Consider Not Using Accessor Methods
- Use Compound Operators
- Use Int Increments
- Be Conscious of Access Speed for Different Variables
- Local Variables are Faster than Class Variables
- Class Variables are Faster than Array Accesses
- Use Faster Types as Loop Indexes
- Use Native Methods
- Use Network Timeouts
- Buffer Network and File I/O
- Use Sockets Rather than URLs
- Use UDP
- Use Threads
- Use notify
- Use Synchronization Sparingly
- Keep Synchronized Methods Out of Loops
- Watch Out for the Mother Thread
- Counting Down May Be Faster than Counting Up
- Reduce the Number of Strings
- Use String Buffers or Arrays
- Watch Out for Slow Fonts
- Keep the Paint Method Small
- Double Buffer Where Possible for Smoother Graphics
- Use the Runtime to Do Error Checking for You
- Avoid Time Conversions
- Be Wary of RMI, EJBs, and CORBA
- Compilers
- Profile Your Code
- Decompilers
- OS-Level Profiling Tools
- JITs
- Static Compilers
- Virtual Machines
- Runtime Options
- Java Chips
- Java Benchmarks
- Web Sites with Java Performance Info
- Key Recommendations
- 22. Databases
- A. Web Performance Product Lists and Reviews
- Index
- About the Author
- Colophon
- Copyright
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Other Books and Resources > Books
Books
In reading this book, you’ll find that I frequently refer to other books that explain concepts more completely than I can (at least, not without making this book twice its size). Here are books with good explanations of the details.
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Albitz, Paul and Cricket Liu, DNS and Bind (O’Reilly Media, 1997).
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Back, Maurice, Design of the Unix Operating System (Prentice Hall, 1986).
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Ballew, Scott, Managing IP Networks with Cisco Routers (O’Reilly Media, 1997).
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Blake, Russ, Optimizing Windows NT (Microsoft Press, out of print).
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Brooks, Fredrick P., Jr., The Mythical Man-Month (Addison Wesley, 1995).
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Chapman, Brent and Elizabeth Zwicky, Building Internet Firewalls, Second Edition (O’Reilly Media, 2001).
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Cockcroft, Adrian and Richard Pettit, Sun Performance and Tuning, Second Edition (Prentice Hall, 1998). Everything about tuning Solaris and Sun hardware.
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