Nginx Troubleshooting

Alex Kapranoff

• Publisher: Packt Publishing
• Year: 2016
• eBook ISBN: 9781785288654
• Edition: 1
• Topic: Ciencia de la computación
• Subtopic: Desarrollo web

Investigate and solve problems with Nginx-powered websites using a deep understanding of the underlying principles

About This Book

• Solve problems with your Nginx-powered websites before your audience notices anything
• Peek into the Nginx architecture and gain knowledge that will help you be valuable to you in the long run
• Gain knowledge of different types of problems in a step-by-step way

Who This Book Is For

The book is for technical specialists who already use Nginx to serve web pages for their users. Whether you are an experienced system administrator or a new professional, this book will help you do your job in the most efficient way.

What You Will Learn

• Detect and investigate problems with your web servers
• Create correct and professional configuration files
• Get an in-depth understanding of the web server software
• Interpret Nginx log files easily and with actionable insights
• Make your websites respond as fast as possible
• Prevent problems by setting up proper monitoring and alerts

In Detail

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.

Style and approach

This comprehensive tutorial on Nginx troubleshooting takes an practical approach to guiding you through common issues in Nginx server.

Nginx Troubleshooting

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Table of Contents

Nginx Troubleshooting

Credits

About the Author

About the Reviewers

www.PacktPub.com

eBooks, discount offers, and more

Why subscribe?

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Searching for Problems in Nginx Configuration

Introducing basic configuration syntax, directives, and testing

Simple directives

Multiline directives

Include directive

Testing Nginx configuration

The default configuration directory layout

A quick example of modifying the MIME types registry

Default nginx.conf

The http directive

Common mistakes in configuration

Semicolons and newlines

File permissions

Variables

Regular expressions

Summary

2. Searching for Problems in Log Files

Configuring Nginx logging

Logging POST requests

Conditional logging

Logging big request bodies

Creating infrastructure around logs

Configuring log rotation

Working with a lot of log data

Reading logs

Error log record

Summary

3. Troubleshooting Functionality

Processing a complain

Rolling back

Keeping Nginx configuration under source control

Keeping a case journal

Performing the simplest test

Performing the Internet connection test

Testing the general HTTP response traffic

Detecting a lying application

Working around an integration failure

The try_files directive

Setting up automatic removal from upstream

Configuring the good old SSI

Planning for more complete monitoring

Processing a situation of no traffic

Restarting Nginx properly

Investigating lower than usual traffic

Summary

4. Optimizing Website Performance

Why Nginx is so fast?

Optimizing individual upstreams

Optimizing static files

Optimizing PHP backends

Java backends

Optimizing Python and Ruby backends

Optimizing Perl backends

Using thread pools in Nginx

The caching layer of Nginx

Emitting caching headers

Caching in Nginx upstream modules

Caching static files

Replacing external redirects with internal ones

Summary

5. Troubleshooting Rare Specific Problems

Security warnings

Domain name mismatch

Expired certificates

Insecure warnings for valid certificates

The mixed – content warning

Building a secure proxy for the external content

Solving problems with cache

Obsolete pages and VirtualBox

Apache migration problems

Solving problems with WebSockets

Showing a file upload progress bar

Solving the problem of an idle upstream

Summary

6. Monitoring Nginx

Using ngxtop

Getting statistics from http_stub_status

Monitoring Nginx with Munin

Configuring alerts

Getting more status data from Nginx

Using Nginx Plus alternatives

nginx-module-vts

Luameter

nginx-lua-stats

The upsteam_check module in tengine

The requests/sec patch by Catap

The Ustats module

Summary

7. Going Forward with Nginx

System administration

Linux/Unix operating system as a whole

Modern Internet protocols

Specific backend software used in your company

Modern cloud platforms

Automation

Software development

Summary

A. Rare Nginx Error Messages

Index

Nginx Troubleshooting

Copyright © 2016 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: April 2016

Production reference: 1190416

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78528-865-4

www.packtpub.com

Credits

Author

Alex Kapranoff

Reviewers

Titouan Galopin

Valery Kholodkov

Commissioning Editor

Dipika Gaonkar

Acquisition Editor

Reshma Raman

Content Development Editor

Sanjeet Rao

Technical Editor

Mohit Hassija

Copy Editor

Dipti Mankame

Project Coordinator

Judie Jose

Proofreader

Safis Editing

Indexer

Priya Sane

Graphics

Kirk D'Penha

Production Coordinator

Shantanu N. Zagade

Cover Work

Shantanu N. Zagade

About the Author

Alex Kapranoff is an established IT professional with more than 20 years of experience in roles ranging from a database developer to the CTO of a social search engine start-up to an infrastructure manager of a huge web application with hundreds of millions of users. His background allows him to be more on the developer side of things, and he is happy to share some of that perspective with fellow system administration specialists.

About the Reviewers

Titouan Galopin is a certified PHP/Symfony French web architect from Paris. He currently works for SensioLabs, the company behind the PHP framework Symfony, and he has worked for various other companies, including LIIP, Emakina, Ademis, and Coburo.

Titouan graduated in computer science and information technology from the Paris-Saclay University, and he is currently pursuing an engineering degree at the University of Technology of Compiègne.

First as a web developer and then as a web architect since 2012, Titouan has worked on Nginx intensively for PHP applications and Dockerized environments. Within the few years of his work, he has accumulated a lot of experience with Nginx and shares his experience in this book and in the related one, Nginx High Performance, Packt Publishing.

Valery Kholodkov is a seasoned IT professional with a decade of experience in creating, building, scaling, and maintaining industrial-grade web services, web applications, and mobile application backends. Throughout his career, he has worked for well-known brands such as Yandex, Booking.com, and AVG. He currently works as the CTO of QubiQ Digital, a consumer acquisition agency. Valery has a deep understanding of technology, and he is able to express its essence, advantages, and risks to a layman, which makes him an accomplished author and technical reviewer.

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Preface

You will learn how to notes problems before your boss calls you about some pages not loading. You will learn how to find those problems using logs and your usual Linux toolbox. You will also learn how to minimize the probability of problems happening again.

Nginx started as a web acceler...

Table of contents

• Nginx Troubleshooting