xk6-tcp-throttle

K6 extension for TCP connections with bandwidth throttling and ACK delay control.

Features

• TCP connection with receive buffer control
• Bandwidth throttling (bytes per second)
• ACK delay simulation for natural bandwidth throttling
• Compatible with K6 load testing

Installation

xk6 build --with github.com/skyloud/xk6-tcp-throttling

Usage

import tcpThrottle from 'k6/x/tcp-throttling';

export default function() {
  const conn = tcpThrottle.connect('server:80');
  
  // Method 1: Bandwidth throttling (1MB/s)
  conn.setBandwidthLimit(1024 * 1000);
  const data1 = conn.readWithThrottle(8192);
  
  // Method 2: ACK delay simulation
  const data2 = conn.readWithDelay(8192, 100);
  
  // Method 3: TCP window control
  conn.setReceiveBuffer(1024);
  
  conn.close();
}

API

• connect(addr) - Create TCP connection
• setBandwidthLimit(bytesPerSecond) - Set bandwidth limit
• readWithThrottle(size) - Read with automatic bandwidth throttling
• setReceiveBuffer(size) - Set SO_RCVBUF socket option
• readWithDelay(size, delayMs) - Read data with ACK delay
• write(data) - Write data
• close() - Close connection

Credits

Bandwidth throttling implementation inspired by go-throttle