How to Check Apache Error Logs on a CentOS VDS?

Setting up and maintaining an Apache web server on a CentOS VDS requires constant monitoring. Apache error logs are your main source of information for identifying and troubleshooting issues affecting website performance. In this article, we will take a detailed look at how to effectively check and analyze Apache error logs on your CentOS VDS to ensure the stable and uninterrupted operation of your web applications.

We will cover the main log files, tools for analyzing them, as well as methods for filtering and interpreting the information contained in the logs. By following these instructions, you will be able to quickly diagnose problems, prevent failures, and maintain optimal performance of your web server.

Main Apache Log Files

Apache records information about its operation in several log files. The most important ones are the error log and the access log. Let's examine each of them in more detail, and also consider where they are located by default on a CentOS VDS. Error log (error.log): This file contains records of all errors, warnings, and other important events related to Apache's operation. It is the primary source of information for diagnosing problems. Access log (access.log): This file contains records of all requests that have been processed by the Apache server. It can be useful for analyzing traffic, identifying bots, and other monitoring purposes. Default location of log files: On CentOS, the standard location for Apache log files is usually as follows:

• /var/log/httpd/error_log - Error Log
• /var/log/httpd/access_log - Access Log

However, this location can be changed in the Apache configuration file. Let's look at how to find the actual location of the log files.

Finding the Location of Log Files in Apache Configuration

To find the exact location of the log files, you need to view the Apache configuration file. It is usually located at /etc/httpd/conf/httpd.conf or in files located in the /etc/httpd/conf.d/ directory. Example 1: Searching for ErrorLog in httpd.conf

grep -i "ErrorLog" /etc/httpd/conf/httpd.conf

This command will search for the string "ErrorLog" (case-insensitive) in the file /etc/httpd/conf/httpd.conf and output the line containing the path to the error log file.