Book Image

Mastering NGINX - Second Edition

By : Dimitri Aivaliotis
Book Image

Mastering NGINX - Second Edition

By: Dimitri Aivaliotis

Overview of this book

NGINX is a high-performance HTTP server and mail proxy designed to use very few system resources. But despite its power it is often a challenge to properly configure NGINX to meet your expectations. Mastering Nginx is the solution – an insider’s guide that will clarify the murky waters of NGINX’s configuration. Tune NGINX for various situations, improve your NGINX experience with some of the more obscure configuration directives, and discover how to design and personalize a configuration to match your needs. To begin with, quickly brush up on installing and setting up the NGINX server on the OS and its integration with third-party modules. From here, move on to explain NGINX's mail proxy module and its authentication, and reverse proxy to solve scaling issues. Then see how to integrate NGINX with your applications to perform tasks. The latter part of the book focuses on working through techniques to solve common web issues and the know-hows using NGINX modules. Finally, we will also explore different configurations that will help you troubleshoot NGINX server and assist with performance tuning.
Table of Contents (20 chapters)
Mastering NGINX - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Directive Reference
Persisting Solaris Network Tunings
Index

Analyzing log files


Before going into a prolonged debugging session trying to track down the cause of a problem, it is usually helpful to first look at the log files. They will often provide the clue we need to track down the error and correct it. The messages that appear in error_log can sometimes be a bit cryptic, however, so we will discuss the format of the log entries, and then take a look at a few examples to show you how to interpret what they mean.

The formats of the error_log file

NGINX uses a couple of different logging functions that produce the error_log entries. The formats used with these functions take on the following patterns:

<timestamp> [log-level] <master/worker pid>#0: message

Consider the following example:

2012/10/14 18:56:41 [notice] 2761#0: using inherited sockets from "6;"

This is an example of informational messages (log level notice). In this case, an nginx binary has replaced a previously-running one, and was able to successfully inherit the old binary...