How to Enable Open_File_Cache on Nginx in Linux

When it comes to optimizing the performance of your Nginx web server, enabling open_file_cache is one of the most effective methods. Open_file_cache is an Nginx feature that caches frequently used files in memory, reducing the number of disk I/O operations required to access those files. This results in faster page load times and improved overall server performance. This article will discuss how to enable open_file_cache on Nginx in Linux, along with its benefits and implementation steps.

What is Open_File_Cache in Nginx?

Open_file_cache is an Nginx directive that caches the file descriptors of frequently accessed files in memory. This reduces the number of disk I/O operations required to access those files and enhances the performance of the Nginx web server. Open_file_cache is especially useful for sites with high traffic, as it reduces the load on the disk and helps the server to serve more requests faster.

Benefits of Open_File_Cache on Nginx:

• Improved Server Performance: By caching frequently accessed files in memory, open_file_cache reduces the disk I/O operations required to access those files, resulting in faster page load times and improved server performance.
• Reduced Disk Load: Open_file_cache minimizes the load on the disk by caching frequently used files in memory, thus freeing up disk space and improving the overall performance of the Nginx server.
• Increased Concurrent Connections: By reducing the load on the disk, open_file_cache also increases the number of concurrent connections the Nginx server can handle, leading to improved overall scalability.

Enable open_file_cache on Nginx

To begin, open your Nginx configuration file using a text editor. For many users, the commonly used text editor is nano, and the path to the Nginx configuration file is typically located at /etc/nginx/nginx.conf.

sudo nano /etc/nginx/nginx.conf

Include the following line in the configuration file:

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

Example of Using Open_File_Cache in 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;
        }
    }
}

Once you have made the necessary changes, save the file by pressing CTRL+X and confirm the save by pressing Y in the nano text editor. Then, exit the editor.

Linux and Nginx users may be curious about the purpose behind each line of configuration. This guide will explain the terms used in each line, such as in the example above.

open_file_cache max=10000 inactive=10s;

This line sets the maximum number of file descriptors that can be cached in memory to 10000 and the time interval after which the file descriptors will be purged from the cache to 10 seconds.

open_file_cache_valid 60s;

This line sets the time interval when the cached file descriptors will be considered valid and re-used without re-opening the files. In this example, the cached file descriptors will be regarded as valid for 60 seconds.

open_file_cache_min_uses 2;

This line sets the minimum number of uses for a file before adding it to the open_file_cache. In this example, the file must be used at least 2 times before it is added to the open_file_cache.

open_file_cache_errors on;

This line enables open_file_cache for files that result in errors when being opened. When this directive is set to “on,” Nginx will cache files that result in errors and re-use the cached file descriptor for subsequent requests.

These examples are just a few of Nginx’s possible configurations for open_file_cache. You can customize these directives to fit the specific needs of your web server and improve its performance.

Finally, before starting Nginx in a live environment, verifying that the open_file_cache syntax added is running correctly is essential. This can be done by using the following command:

nginx -t

Upon successful implementation, the following output should be displayed:

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

Initiate a restart of the Nginx server using the following command:

sudo systemctl restart nginx

Conclusion

In conclusion, enabling open_file_cache on Nginx in Linux is an effective way to improve the performance of your web server. By caching frequently accessed files in memory, open_file_cache reduces the number of disk I/O operations required to access those files and enhances the overall performance of the Nginx server. With the step-by-step instructions and frequently asked questions provided in this article, you can quickly implement open_file_cache on Nginx and start experiencing the benefits of this powerful feature.