FastCGI cache in Nginx - Mini Project: Build & Apply

Setting Up FastCGI Cache in Nginx

📖 Scenario: You manage a busy website using Nginx as the web server. To improve performance and reduce load on your backend PHP server, you want to set up FastCGI caching. This cache will store dynamic page responses temporarily, so repeated requests are served faster.

🎯 Goal: Learn how to configure FastCGI cache in Nginx step-by-step. You will create the cache path, define cache settings, apply caching to a server block, and verify the cache is working.

📋 What You'll Learn

Create a FastCGI cache path with specific keys and inactive time

Define cache key and cache zone in Nginx configuration

Apply FastCGI cache settings to a server location block

Test and display cache status using HTTP headers

💡 Why This Matters

🌍 Real World

FastCGI caching speeds up dynamic websites by storing generated pages temporarily, reducing backend load and improving user experience.

💼 Career

Understanding FastCGI cache setup is essential for DevOps roles managing high-traffic web servers and optimizing performance.

1

Create FastCGI Cache Path

Create a FastCGI cache path called fastcgi_cache_path with the directory /var/cache/nginx/fastcgi_cache, a cache key zone named FASTCGI_CACHE with 10 megabytes of storage, and set the inactive time to 60m.

Nginx

# Your code here

Need a hint?

Use fastcgi_cache_path directive with levels, keys_zone, and inactive parameters.

2

Define Cache Key and Zone

Define a variable $cache_key that combines $scheme, $host, and $request_uri. Then, inside the http block, set fastcgi_cache_key to $cache_key and reference the cache zone FASTCGI_CACHE.

Nginx

fastcgi_cache_path /var/cache/nginx/fastcgi_cache levels=1:2 keys_zone=FASTCGI_CACHE:10m inactive=60m;
# Your code here

Need a hint?

Use set to define $cache_key. Inside http block, set fastcgi_cache_key and fastcgi_cache.

3

Apply FastCGI Cache to Server Location

Inside the server block, add a location / block. Configure it to use fastcgi_cache FASTCGI_CACHE, enable fastcgi_cache_valid 200 10m to cache successful responses for 10 minutes, and set fastcgi_pass to unix:/run/php/php7.4-fpm.sock.

Nginx

fastcgi_cache_path /var/cache/nginx/fastcgi_cache levels=1:2 keys_zone=FASTCGI_CACHE:10m inactive=60m;

set $cache_key "$scheme://$host$request_uri";

http {
    fastcgi_cache_key $cache_key;
    fastcgi_cache FASTCGI_CACHE;

    server {
        listen 80;
        server_name example.com;

        location / {
            # Your code here
        }
    }
}

Need a hint?

Inside location /, set fastcgi_cache, fastcgi_cache_valid, and fastcgi_pass directives.

4

Verify FastCGI Cache Status

Add a header X-Cache-Status inside the location / block to show cache status using add_header X-Cache-Status $upstream_cache_status;. Then, print the command to test the cache status by running curl -I http://example.com/.

Nginx

fastcgi_cache_path /var/cache/nginx/fastcgi_cache levels=1:2 keys_zone=FASTCGI_CACHE:10m inactive=60m;

set $cache_key "$scheme://$host$request_uri";

http {
    fastcgi_cache_key $cache_key;
    fastcgi_cache FASTCGI_CACHE;

    server {
        listen 80;
        server_name example.com;

        location / {
            fastcgi_cache FASTCGI_CACHE;
            fastcgi_cache_valid 200 10m;
            fastcgi_pass unix:/run/php/php7.4-fpm.sock;
            # Your code here
        }
    }
}

# Print the curl command below

Need a hint?

Use add_header X-Cache-Status $upstream_cache_status; inside location /. Then print the curl command to test.