Nginx Performance Tuning

# -----------------------------------------------
#  worker_processes / worker_connections
# -----------------------------------------------

# worker_processes {number | auto}
#   → Sets the number of Nginx worker processes.
#   → Use auto to match the number of CPU cores automatically.
#   Example: worker_processes auto;

# worker_connections {number}
#   → Sets the maximum number of simultaneous connections per worker process.
#   → Total concurrent connections = worker_processes × worker_connections.
#   Example: worker_connections 1024;

# -----------------------------------------------
#  keepalive_timeout
# -----------------------------------------------

# keepalive_timeout {seconds} [{header seconds}]
#   → Sets how long (in seconds) to keep an HTTP Keep-Alive connection open.
#   → Higher values reduce connection overhead, but hold file descriptors
#     (FDs) open longer.
#   → Values between 10 and 30 seconds are common in production.
#   Example: keepalive_timeout 15;

# -----------------------------------------------
#  sendfile / tcp_nopush / tcp_nodelay
# -----------------------------------------------

# sendfile {on | off}
#   → Uses the kernel's sendfile(2) system call to send files.
#   → Transfers data directly from disk to network, bypassing user space,
#     which speeds up static file delivery.
#   Example: sendfile on;

# tcp_nopush {on | off}
#   → Effective when sendfile is on. Combines the response header and the
#     beginning of the file into a single TCP packet.
#   → Use together with sendfile on.
#   Example: tcp_nopush on;

# tcp_nodelay {on | off}
#   → Disables the Nagle algorithm, sending small packets immediately.
#   → Effective for keepalive connections.
#   Example: tcp_nodelay on;

# -----------------------------------------------
#  gzip compression
# -----------------------------------------------

# gzip {on | off}
#   → Enables gzip compression for responses.
#   Example: gzip on;

# gzip_types {MIME type ...}
#   → Specifies which MIME types to compress.
#   → text/html is always compressed and does not need to be listed here.
#   Example: gzip_types text/plain text/css application/json application/javascript text/xml;

# gzip_comp_level {1-9}
#   → Sets the gzip compression level.
#   → 1 is fastest (least compression), 9 is highest compression (slowest).
#   → A value of 4-6 is recommended for a good balance of CPU cost and ratio.
#   Example: gzip_comp_level 5;

# gzip_min_length {bytes}
#   → Responses smaller than this size will not be compressed.
#   → Compressing very small files yields little benefit; 256-1024 bytes is common.
#   Example: gzip_min_length 256;

# gzip_vary {on | off}
#   → Adds a Vary: Accept-Encoding header to responses.
#   → Needed so CDNs and proxies can correctly cache both compressed and
#     uncompressed versions.
#   Example: gzip_vary on;

# -----------------------------------------------
#  Buffers / client size limits
# -----------------------------------------------

# client_max_body_size {size}
#   → Sets the maximum allowed size of the client request body.
#   → Increase this when your application accepts file uploads.
#   Example: client_max_body_size 10m;

# client_body_buffer_size {size}
#   → Sets the in-memory buffer size for reading the request body.
#   → Data exceeding this size is written to a temporary file on disk.
#   Example: client_body_buffer_size 16k;

# -----------------------------------------------
#  File cache
# -----------------------------------------------

# open_file_cache max={number} inactive={seconds}
#   → Caches file descriptors, file sizes, and modification times.
#   → Reduces disk I/O on servers that serve many static files.
#   Example: open_file_cache max=1000 inactive=30s;

# open_file_cache_valid {seconds}
#   → Sets how often cached entries are revalidated.
#   Example: open_file_cache_valid 60s;

/etc/nginx/nginx.conf

# -----------------------------------------------
#  Nginx performance tuning for production
#  Kiryu Group EC site (kiryu-group.example.com)
# -----------------------------------------------

# Automatically set the number of worker processes to match CPU cores.
worker_processes auto;

# Set the maximum number of file descriptors Nginx can open.
# Should be greater than the total of all worker_connections.
worker_rlimit_nofile 65535;

events {
    # Maximum simultaneous connections per worker.
    # Total connection limit = worker_processes × worker_connections.
    worker_connections 1024;

    # Linux only. Accepts multiple connections at once.
    multi_accept on;
}

http {
    # -----------------------------------------------
    #  Basic settings
    # -----------------------------------------------

    # Load the MIME type definitions file.
    include /etc/nginx/mime.types;
    default_type  application/octet-stream;

    # -----------------------------------------------
    #  Static file transfer optimization
    # -----------------------------------------------

    # Use the kernel's sendfile() to send files directly to the network.
    sendfile        on;

    # Combine the response header and the start of the file into one packet.
    # (Only effective when sendfile is on.)
    tcp_nopush      on;

    # Send small data immediately over Keep-Alive connections.
    tcp_nodelay     on;

    # -----------------------------------------------
    #  Keep-Alive settings
    # -----------------------------------------------

    # Keep client connections alive for 15 seconds.
    # Too short increases reconnection cost; too long holds FDs open.
    keepalive_timeout 15;

    # -----------------------------------------------
    #  File cache (useful when serving many static files)
    # -----------------------------------------------

    # Cache file descriptors, sizes, and modification times in memory.
    # Entries not accessed within 30 seconds are released.
    open_file_cache          max=1000 inactive=30s;

    # Revalidate cached entries every 60 seconds.
    open_file_cache_valid    60s;

    # -----------------------------------------------
    #  gzip compression
    # -----------------------------------------------

    # Enable gzip compression.
    gzip              on;

    # text/html is always compressed (no need to list it here).
    # Add other common text-based MIME types below.
    gzip_types
        text/plain
        text/css
        text/javascript
        application/json
        application/javascript
        application/x-javascript
        text/xml
        application/xml
        application/xml+rss
        image/svg+xml;

    # Level 5 offers a good balance between CPU cost and compression ratio.
    gzip_comp_level   5;

    # Do not compress responses smaller than 256 bytes.
    gzip_min_length   256;

    # Allow CDNs and reverse proxies to correctly cache compressed responses.
    gzip_vary         on;

    # -----------------------------------------------
    #  Client size limits
    # -----------------------------------------------

    # Allow up to 20 MB for image and video uploads.
    client_max_body_size     20m;

    # In-memory buffer for request bodies (overflow is written to disk).
    client_body_buffer_size  16k;

    # -----------------------------------------------
    #  Virtual host configuration
    # -----------------------------------------------

    # Kiryu Group EC site
    server {
        listen       80;
        server_name  kiryu-group.example.com;

        root /var/www/html/kiryu-shop;
        index  index.php index.html;

        # Set long-term cache headers for static assets.
        location ~* \.(css|js|jpg|jpeg|png|gif|ico|woff2)$ {
            expires 30d;
            add_header Cache-Control "public, immutable";
        }

        location / {
            try_files $uri $uri/ /index.php?$query_string;
        }

        location ~ \.php$ {
            fastcgi_pass   unix:/run/php/php8.2-fpm.sock;
            fastcgi_index  index.php;
            include        fastcgi_params;
            fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
        }
    }
}

Run the following command:

$ sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
$ sudo systemctl reload nginx
$ curl -I -H "Accept-Encoding: gzip" https://kiryu-group.example.com/
HTTP/2 200
server: nginx/1.26.0
content-type: text/html; charset=UTF-8
content-encoding: gzip
vary: Accept-Encoding

Nginx performance tuning is divided into four main areas: process configuration, static file transfer, connection management, and compression. Use worker_processes auto to fully utilize all CPU cores, and combine sendfile on with tcp_nopush on for kernel-level high-speed file transfers. Setting keepalive_timeout to an appropriate value (around 10–30 seconds) reduces connection re-establishment overhead while avoiding unnecessary resource usage. gzip compression significantly reduces the size of text-based responses such as HTML, CSS, and JavaScript, cutting network transfer volume. Note that images (JPEG, PNG) are already compressed and should not be included in gzip_types. For basic Nginx server block configuration, see Nginx Configuration. For HTTPS and TLS security settings, see Nginx SSL Configuration.