How to Enable Open File Cache in Nginx

NGINX is a high-performance web server with many features to optimize server performance and efficiency. One such feature is the open file cache, which helps improve performance by caching information about open files. This reduces the number of system calls needed to access file information, resulting in faster response times and reduced load on the server. Enabling the open file cache in NGINX can significantly enhance the performance of your web server, especially under high-load conditions.

This guide will explain how to enable and configure the open file cache in NGINX, offering step-by-step instructions to optimize your server’s performance.

Enable Open File Cache in Nginx

Accessing the Nginx Configuration File

To enable Open File Cache, start by accessing the Nginx configuration file. This file is usually located at /etc/nginx/nginx.conf. Open it with a text editor like Nano:

sudo nano /etc/nginx/nginx.conf

Configuring Open File Cache in Nginx

Inside the configuration file, insert the following directives to enable Open File Cache:

open_file_cache max=10000 inactive=10s;
open_file_cache_valid 60s;
open_file_cache_min_uses 2;
open_file_cache_errors on;

Example Configuration Open File Cache in Nginx

Below is an example showing these settings in a standard Nginx configuration:

http {
    open_file_cache max=10000 inactive=10s;
    open_file_cache_valid 60s;
    open_file_cache_min_uses 2;
    open_file_cache_errors on;

    server {
        listen 80;
        server_name example.com;

        location / {
            root /var/www/example.com;
            index index.html;
        }
    }
}

After incorporating these settings, ensure to save your changes in the nano text editor by pressing CTRL+X, then confirm the save by pressing Y. Following this, exit the editor.

Understanding the Open File Cache in Nginx Configuration

Each line in the above configuration plays a crucial role:

• Max Cache Size and Inactivity Period: open_file_cache max=10000 inactive=10s; sets the maximum number of file descriptors to cache (10,000) and specifies the duration (10 seconds) after which inactive files are removed from the cache.
• Validity Period of Cached Files: open_file_cache_valid 60s dictates how long the cached files remain valid. Here, it’s set to 60 seconds.
• Minimum Usage for Caching: open_file_cache_min_uses 2; this determines the minimum number of times a file must be accessed before being cached, which is set to 2 in this example.
• Caching File Errors: open_file_cache_errors on; allows caching of file descriptors even when file opening results in errors, enhancing efficiency in error handling.

These configurations offer a balanced approach, optimizing file caching while maintaining server performance.

Verifying and Restarting Nginx

Before implementing these changes in a live environment, verify the correctness of your configuration:

nginx -t

Upon successful implementation, the following output should be displayed:

nginx: configuration file /etc/nginx/nginx.conf test is successful

Finally, restart the Nginx server to apply changes:

sudo systemctl restart nginx

Conclusion

By enabling the open file cache in NGINX, you can improve your server’s response times and overall performance. Regularly monitor the effects of this configuration to ensure it provides the desired benefits and adjust settings as needed. Implementing the open file cache is a powerful way to optimize NGINX, making your web server more efficient and capable of handling higher traffic loads.