Configuring an Nginx server for high-traffic applications requires careful tuning to ensure performance, scalability, and reliability. Unlike basic setups, a high-traffic environment demands optimization at every level—from worker processes to caching and load balancing. Here’s how you can approach it in a way that feels natural rather than a rigid checklist. First, start with **worker processes and connections**. Nginx uses an event-driven model, so you’ll want to match the number of `worker_processes` to your CPU cores for optimal resource utilization. For example, if your server has 8 cores, set: ```nginx worker_processes auto; # Automatically detects CPU cores events { worker_connections 1024; # Increases the number of connections per worker multi_accept on; # Allows a worker to accept multiple connections at once } ``` The `worker_connections` value should be high enough to handle concurrent requests, but keep an eye on system limits (`ulimit -n`). Next, **buffers and timeouts** need adjustment to prevent bottlenecks. Large headers or slow clients can tie up resources, so tweak these settings: ```nginx client_max_body_size 10m; # Limits upload size to 10MB client_body_buffer_size 128k; client_header_buffer_size 1k; large_client_header_buffers 4 4k; keepalive_timeout 15; # Reduces keep-alive time to free up connections send_timeout 10; # Terminates slow send operations ``` For **static content**, enable `sendfile` and `tcp_nopush` to optimize file delivery and reduce overhead: ```nginx sendfile on; tcp_nopush on; tcp_nodelay on; # Disables Nagle’s algorithm for real-time traffic ``` **Caching** is critical for high-traffic apps. Configure proxy caching for dynamic content and enable FastCGI caching for PHP applications. Here’s a basic proxy cache setup: ```nginx proxy_cache_path /path/to/cache levels=1:2 keys_zone=my_cache:10m inactive=60m use_temp_path=off; server { location / { proxy_cache my_cache; proxy_pass http://backend; proxy_cache_valid 200 302 10m; } } ``` For **load balancing**, distribute traffic across multiple backend servers using Nginx’s `upstream` module. A simple round-robin setup looks like this: ```nginx upstream backend { server 10.0.0.1; server 10.0.0.2; server 10.0.0.3; } server { location / { proxy_pass http://backend; } } ``` Finally, **enable Gzip compression** to reduce bandwidth usage and speed up transfers: ```nginx gzip on; gzip_types text/plain text/css application/json application/javascript; gzip_min_length 1024; ``` These tweaks, combined with monitoring (like `ngx_http_stub_status_module`), will help your Nginx server handle high traffic efficiently. Always test changes in staging and adjust based on real-world performance metrics.