HTTP/2 is the second major version of the HTTP network protocol, which brings significant improvements over HTTP/1.1, including reduced latency, multiplexing, header compression, and more. In this section, we will explore how to configure NGINX to support HTTP/2, understand its benefits, and see practical examples.

1. HTTP/2 Benefits:

   • Multiplexing: Multiple requests and responses can be sent over a single TCP connection.
   • Header Compression: Reduces overhead by compressing HTTP headers.
   • Server Push: Allows the server to send resources to the client before they are requested.
   • Stream Prioritization: Clients can prioritize streams, improving performance.

2. Prerequisites:

   • NGINX version 1.9.5 or later.
   • SSL/TLS configuration, as HTTP/2 requires HTTPS.

1. Ensure NGINX Version:

   • Check your NGINX version to ensure it supports HTTP/2.

   nginx -v
   

2. Update NGINX Configuration:

   • Open your NGINX configuration file (usually located at /etc/nginx/nginx.conf or /etc/nginx/sites-available/default).
   • Modify the listen directive to include http2.

   server {
       listen 443 ssl http2;
       server_name example.com;
   
       ssl_certificate /path/to/your/certificate.crt;
       ssl_certificate_key /path/to/your/private.key;
   
       # Other SSL settings
       ssl_protocols TLSv1.2 TLSv1.3;
       ssl_ciphers HIGH:!aNULL:!MD5;
   
       location / {
           root /usr/share/nginx/html;
           index index.html;
       }
   }
   

3. Restart NGINX:

   • Apply the changes by restarting NGINX.

   sudo systemctl restart nginx
   

Let's configure a simple NGINX server block to serve a static website over HTTP/2.

1. Using Browser Developer Tools:

   • Open your website in a browser.
   • Open Developer Tools (F12 or right-click and select "Inspect").
   • Go to the "Network" tab and reload the page.
   • Check the protocol column to see if HTTP/2 is being used.

2. Using Online Tools:

   • Use online tools like KeyCDN HTTP/2 Test to verify if your site supports HTTP/2.

1. SSL/TLS Configuration Issues:

   • Ensure your SSL certificate and key paths are correct.
   • Use strong SSL protocols and ciphers.

2. NGINX Version:

   • Ensure you are using NGINX version 1.9.5 or later.

3. Browser Compatibility:

   • Ensure the browser you are using supports HTTP/2.

1. Objective: Configure your NGINX server to support HTTP/2.
2. Steps:
   • Ensure you have a valid SSL certificate.
   • Modify your NGINX configuration to include http2 in the listen directive.
   • Restart NGINX and verify the configuration using browser developer tools or an online HTTP/2 test tool.

1. Configuration:

   server {
       listen 443 ssl http2;
       server_name yourdomain.com;
   
       ssl_certificate /path/to/your/certificate.crt;
       ssl_certificate_key /path/to/your/private.key;
   
       ssl_protocols TLSv1.2 TLSv1.3;
       ssl_ciphers HIGH:!aNULL:!MD5;
   
       location / {
           root /var/www/yourdomain;
           index index.html;
       }
   }
   

2. Restart NGINX:

   sudo systemctl restart nginx
   

3. Verification:

   • Use browser developer tools or an online HTTP/2 test tool to verify the configuration.

In this section, we learned about the benefits of HTTP/2 and how to enable it in NGINX. We covered the necessary configuration steps, practical examples, and common mistakes. By enabling HTTP/2, you can significantly improve the performance and efficiency of your web server. In the next section, we will explore how to use NGINX with gRPC.