Book Image

Nginx Troubleshooting

By : Alexey Kapranov
Book Image

Nginx Troubleshooting

By: Alexey Kapranov

Overview of this book

Nginx is clearly winning the race to be the dominant software to power modern websites. It is fast and open source, maintained with passion by a brilliant team. This book will help you maintain your Nginx instances in a healthy and predictable state. It will lead you through all the types of problems you might encounter as a web administrator, with a special focus on performance and migration from older software. You will learn how to write good configuration files and will get good insights into Nginx logs. It will provide you solutions to problems such as missing or broken functionality and also show you how to tackle performance issues with the Nginx server. A special chapter is devoted to the art of prevention, that is, monitoring and alerting services you may use to detect problems before they manifest themselves on a big scale. The books ends with a reference to error and warning messages Nginx could emit to help you during incident investigations.
Table of Contents (15 chapters)
Nginx Troubleshooting
About the Author
About the Reviewers
Rare Nginx Error Messages

Chapter 3. Troubleshooting Functionality

You get a call in the middle of the night. "Our website isn't working," your boss yells. In seconds, you are wide awake and trying to remember "what exactly did we change yesterday?"—this is a very natural reaction for every system administrator on this planet.

Have you ever been in such a situation? This is a stress test for each young sysadmin, and we hope you have had this earlier in your career rather than later because it is a teaching experience. Fortunately, websites usually malfunction when they are mostly loaded and this happens during the late morning or early evening hours—if you are lucky to live in roughly the same time zone as your target audience. For example, this is a traffic graph for a big website in Russia, which is a country very centered around its two capitals, and those cities are both in UTC+03 time zone as of 2016:

As you can see, the real traffic comes in the morning, has a peak in the evening, and falls sharply as people...