Tune Nginx for High Performance

# /etc/nginx/nginx.conf
worker_processes auto;        # One per CPU core
worker_rlimit_nofile 65535;   # File descriptor limit

events {
    worker_connections 4096;  # Max connections per worker
    multi_accept on;          # Accept multiple connections at once
    use epoll;                # Linux: efficient event processing
}

http {
    # Connection keepalive
    keepalive_timeout 65;
    keepalive_requests 100;

    # Buffer tuning
    client_body_buffer_size 16k;
    client_header_buffer_size 1k;
    client_max_body_size 16m;
    large_client_header_buffers 4 8k;

    # File handling
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;

    # Mime types
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    # Logging
    access_log /var/log/nginx/access.log combined buffer=512k flush=1m;
    error_log /var/log/nginx/error.log warn;
}

gzip on;
gzip_vary on;
gzip_proxied any;
gzip_comp_level 4;
gzip_min_length 256;
gzip_types
    text/plain
    text/css
    text/javascript
    application/javascript
    application/json
    application/xml
    image/svg+xml
    font/woff2;

# Cache static assets
location ~* \.(jpg|jpeg|png|gif|ico|svg|webp)$ {
    expires 1y;
    add_header Cache-Control "public, immutable";
    access_log off;
}

location ~* \.(css|js)$ {
    expires 1y;
    add_header Cache-Control "public, immutable";
    access_log off;
}

location ~* \.(woff|woff2|ttf|otf|eot)$ {
    expires 1y;
    add_header Cache-Control "public, immutable";
    access_log off;
}

# Define cache zone
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=app_cache:10m max_size=1g inactive=60m use_temp_path=off;

server {
    location /api/ {
        proxy_pass http://backend;
        proxy_cache app_cache;
        proxy_cache_valid 200 10m;
        proxy_cache_valid 404 1m;
        proxy_cache_use_stale error timeout updating;
        add_header X-Cache-Status $upstream_cache_status;
    }
}