pm.max_children — glossary
TL;DR
PHP-FPM pool cap on concurrent workers — primary OOM lever.
Key facts
- Term
- pm.max_children
TL;DR
pm.max_children is the maximum number of PHP-FPM worker processes that may run at once. It is the single biggest knob for Laravel capacity — and the most common cause of "pool reached" alerts.
Rule of thumb
pm.max_children ≈ (available RAM for PHP) / (average worker RSS)
Leave headroom for MySQL, Redis, and the OS page cache.