How to Use tcp_nopush in Nginx for Better Network Performance

In Nginx, you enable tcp_nopush by setting it to on inside the http or server block. This option helps Nginx send headers and data in fewer packets, improving network performance by reducing overhead.

Syntax

The tcp_nopush directive controls whether Nginx uses the TCP_CORK option on Linux to optimize packet sending. It accepts two values:

• on: Enables TCP_CORK to delay sending packets until enough data is ready.
• off: Disables TCP_CORK, sending packets immediately.

This directive is placed inside the http, server, or location blocks.

nginx

tcp_nopush on | off;

Example

This example shows how to enable tcp_nopush in the http block of your Nginx configuration to improve performance when sending large files.

nginx

http {
    tcp_nopush on;

    server {
        listen 80;
        server_name example.com;

        location / {
            root /var/www/html;
            index index.html;
        }
    }
}

Common Pitfalls

Common mistakes when using tcp_nopush include:

• Enabling tcp_nopush without sendfile enabled, which reduces its effectiveness.
• Using tcp_nopush on non-Linux systems where it has no effect.
• Not combining tcp_nopush with tcp_nodelay off for optimal packet coalescing.

Always ensure sendfile on; is set to benefit from tcp_nopush.

nginx

http {
    sendfile on;
    tcp_nopush on;
    tcp_nodelay off;

    server {
        listen 80;
        server_name example.com;

        location / {
            root /var/www/html;
            index index.html;
        }
    }
}

Quick Reference

Directive	Description	Typical Value
tcp_nopush	Enables TCP_CORK to optimize packet sending	on
sendfile	Enables zero-copy file transfer	on
tcp_nodelay	Controls Nagle's algorithm; usually off with tcp_nopush	off

Key Takeaways

Enable tcp_nopush in the http or server block to optimize packet sending.

Always use tcp_nopush with sendfile on for best performance.

Set tcp_nodelay off when tcp_nopush is on to allow packet coalescing.

tcp_nopush works only on Linux systems using TCP_CORK.

Misconfiguration can cause delays or no performance gain.