Getting Started with Varnish Cache : Accelerate Your Web Applications

How long does it take for your website to load? Web performance is just as critical for small and medium-sized websites as it is for massive websites that receive tons of hits. Before you pour money and time into rewriting your code or replacing your infrastructure, first consider a reverse-caching proxy server like Varnish. With this practical book, you’ll learn how Varnish can give your website or API an immediate performance boost.

Varnish mimicks the behavior of your webserver, caches its output in memory, and serves the result directly to clients without having to access your webserver. If you're a web developer familiar with HTTP, this book helps you master Varnish basics, so you can get up and running in no time. You'll learn how to use the Varnish Configuration Language and HTTP best practices to achieve faster performance and a higher hit rate.

• Understand how Varnish helps you gain optimum web performance
• Use HTTP to improve the cache-ability of your websites, web applications, and APIs
• Properly invalidate your cache when the origin data changes
• Optimize access to your backend servers
• Avoid common mistakes when using Varnish in the wild
• Use logging and debugging tools to examine the behavior of Varnish

Table of Content

Forcing a Cache Miss

Cache Invalidation Is Hard

Conclusion

Chapter 6Dealing with Backends

Backend Selection

Backend Health

Directors

Grace Mode

Conclusion

Chapter 7Improving Your Hit Rate

Common Mistakes

Do You Really Want to Cache Static Assets?

URL Blacklists and Whitelists

Decide What Gets Cached with Cache-ControlHeaders

There Will Always Be Cookies

Sanitizing

Hit/Miss Marker

Caching Blocks

An All-in-One Code Example

Conclusion

Chapter 8Logging, Measuring, and Debugging

Varnishstat

Varnishlog

Varnishtop

Conclusion

Chapter 9What Does This Mean for YourBusiness?

To CDN or Not to CDN

VCL Is Cheaper

Varnish as a Building Block

The Original Customer Case

Varnish Plus

Companies Using Varnish Today

Conclusion

Chapter 10Taking It to the Next Level

What About RESTful Services?

Extending Varnish’s Behavior with VMODs

Need Help?

The Future of the Varnish Project