How to optimize Nginx performance and resource usage?

Optimizing Nginx performance and resource usage involves several strategies that can enhance its efficiency and reduce load on the server. Here are some key techniques:

Adjust Worker Processes: Modify the worker_processes directive to match the number of CPU cores available. This ensures that Nginx can handle requests in parallel without overloading the CPU.

Example:
```
worker_processes auto;
```
Optimize Worker Connections: Increase the worker_connections setting to allow more simultaneous connections per worker process. This is particularly useful for servers expecting high traffic.

Example:
```
events {
    worker_connections 1024;
}
```

Enable Gzip Compression: Compressing responses reduces the amount of data transferred, which speeds up delivery and reduces bandwidth usage.

Example:

http {
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
}

Use Caching: Implement caching to store frequently accessed content locally, reducing the need to regenerate content for each request.

Example:
```
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off;
```
Optimize SSL/TLS Settings: Efficient SSL/TLS handling can significantly improve performance. Use protocols and ciphers that offer a good balance between security and performance.

Example:
```
ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers 'HIGH:!aNULL:!MD5';
```

Load Balancing: Distribute incoming traffic across multiple servers to prevent overload on any single server. This can be achieved using Nginx's built-in load balancing features.

Example:

upstream backend {
    server backend1.example.com;
    server backend2.example.com;
}

server {
    location / {
        proxy_pass http://backend;
    }
}

Use a Content Delivery Network (CDN): Offloading static content to a CDN can reduce the load on your Nginx server and improve content delivery speed for users worldwide.

For instance, Tencent Cloud's Cloud Front Service can be integrated with Nginx to enhance content delivery.

By implementing these optimizations, you can significantly improve Nginx's performance and resource usage, leading to a more efficient and responsive web server.