loadgen

Documentation

Overview

Command loadgen puts sustained, controlled concurrency on a PHP-FPM pool.

It exists because verifying fpm-tune needs a pool that is genuinely saturated, and the obvious way to arrange that does not work. A shell loop spawning cgi-fcgi processes serialises on process creation: six "concurrent" requests produced a measured max_active_processes of 2, so the saturation path could not be exercised at all and the tool looked like it was cutting a busy pool when it was reading an idle one.

Goroutines over persistent FastCGI connections hold real concurrency instead, using the same client the tool itself scrapes with.