Robuta

https://grafana.com/oss/k6/?pg=k6-cloud&plcmt=hero-btn-2
Grafana k6 is an open source load testing tool that uses test scripts written in JavaScript to help you easily find and fix issues before they reach production.
load testing toolopen sourcegrafana
https://www.c-sharpcorner.com/Resources/3192/webapi-load-performance-testing-tool.aspx
In this part of content you can find the solution of how to test performance of any web site and web API.
load performance testingwebapitool
https://github.com/TPC-Council/HammerDB
HammerDB Database Load Testing and Benchmarking Tool - TPC-Council/HammerDB
load testinggithubtpccouncilhammerdb
https://github.com/jedisct1/dnsblast
A simple and stupid load testing tool for DNS resolvers - jedisct1/dnsblast
load testing toolgithubsimplestupid