# FastCGI Micro Cache in NGINX

## Introduction

FastCGI Micro Cache is a caching mechanism that caches dynamic content in front of a web server with NGINX. It is the most efficient way to implement a dynamic cache mechanism. In this article, we will discuss how to configure FastCGI Micro Cache in NGINX.

## Configuration

1. Edit the NGINX main configuration file to add the following lines in the `http` context:
    

```nginx
http {
# Configure microcache (fastcgi)
  fastcgi_cache_path /tmp/nginx_cache levels=1:2 keys_zone=ZONE_1:100m inactive=60m;
  fastcgi_cache_key "$scheme$request_method$host$request_uri";
  add_header X-Cache $upstream_cache_status;
```

1. Edit the virtual host configuration file in which caching is to be enabled.
    

1. Add the following content to the `server` context:
    

```nginx
server {
    # Cache by default
    set $no_cache 0;
    # Check for cache bypass
    if ($arg_skipcache = 1) {
      set $no_cache 1;
    }

    location / {
      try_files $uri $uri/ =404;
    }

    location ~\.php$ {
      # Pass php requests to the php-fpm service (fastcgi)
      include fastcgi.conf;
      fastcgi_pass unix:/run/php/php7.1-fpm.sock;

      # Enable cache
      fastcgi_cache ZONE_1;
      fastcgi_cache_valid 200 60m;
      fastcgi_cache_bypass $no_cache;
      fastcgi_no_cache $no_cache;
    }
  }
```

Here’s a brief explanation of the code:

* The `server` block is the top-level configuration context for NGINX. It defines the settings for a virtual server.
    
* The `set` directive is used to set a variable to a value. In this case, `$no_cache` is set to `0` by default.
    
* The `if` directive is used to execute a block of code if a certain condition is met. In this case, it checks if the query parameter `skipcache` is set to `1`. If it is, `$no_cache` is set to `1`.
    
* The `location` directive is used to define how NGINX should handle requests for a specific URL pattern.
    
* The first `location` block defines how NGINX should handle requests for the root URL (`/`). It uses the `try_files` directive to check if the requested file exists and serve it if it does. If it doesn’t exist, it returns a 404 error.
    
* The second `location` block defines how NGINX should handle requests for PHP files (files ending in `.php`). It includes the `fastcgi.conf` file, which contains common FastCGI configuration settings. It then passes the request to the PHP-FPM service using the `fastcgi_pass` directive.
    
* The `fastcgi_cache` directive enables caching for FastCGI requests. In this case, it uses the cache zone named `ZONE_1`.
    
* The `fastcgi_cache_valid` directive sets how long cached content should be considered valid. In this case, it sets it to 60 minutes for responses with a status code of 200.
    
* The `fastcgi_cache_bypass` and `fastcgi_no_cache` directives are used to control when cached content should not be used. In this case, they use the `$no_cache` variable that was set earlier.
    

1. Apply your configuration changes.
    
2. Test out FastCGI Micro Cache using Apache Bench, etc.
    

## Conclusion

FastCGI Micro Cache is an efficient way to implement a dynamic cache mechanism in front of a web server with NGINX. It can help improve website performance and reduce server load. By following the steps outlined in this article, you can easily configure FastCGI Micro Cache in NGINX.

## References

[How to Setup FastCGI Caching with Nginx on your VPS | DigitalOcean](https://www.digitalocean.com/community/tutorials/how-to-setup-fastcgi-caching-with-nginx-on-your-vps)

[NGINX Fundamentals: High Performance Servers from Scratch | Udemy](https://www.udemy.com/course/nginx-fundamentals/learn/lecture/10615254#overview)

[Cache your Web Site with NGINX and FastCGI in CentOS 7 - PHP-FPM (](https://www.ryadel.com/en/cache-website-nginx-fastcgi-centos-7-php-fpm/)[ryadel.com](http://ryadel.com)[)](https://www.ryadel.com/en/cache-website-nginx-fastcgi-centos-7-php-fpm/)