project
PHP-FPM is a FastCGI process manager that runs pools of worker processes to execute PHP code and serve HTTP requests for web applications.
No evidence-backed relationships are recorded.
A dev.to benchmark on Laravel 13.31.0 and PHP 8.4.22 splits a request into framework bootstrap and loaded data. The much-quoted 20MB to 30MB per-request figure turns out to measure PHP with OPcache disabled.
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A dev.to build log measures the GPS endpoint of a ride-hailing platform at a 62ms median, 97 percent of it framework overhead, and finds the real ceiling in an untuned PHP-FPM worker count on an eight-core box.
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Worker occupancy is arrival rate times service time, which is why an in-controller Redis hit only moves the ceiling and an edge proxy is the only layer that stops a request before a worker is allocated.
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A dev.to account of moving a production WooCommerce store down to Nginx FastCGI cache makes its case on concurrency rather than milliseconds, then spends most of its trouble on the WooCommerce cart cookie. That is the right order.
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A dev.to writeup put curl in a loop through its own deploy and got 502 on every request while the app booted, which is the interval the release symlink never covered, and the nginx retry line most teams paste in points at an upstream group of one.
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Roughly 2 GB per JavaScript build, a hard failure floor at 2 GB of RAM, and a formula that subtracts headroom first. Exceed it and the 504s land on sites nobody was deploying.
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A dev.to writeup swaps a hardcoded Laravel worker count for one declared SLA and pending-over-throughput math. The measured run shows where the formula stops and the caps take over.
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A developer watched fpm-status in real time and reduced pm = dynamic to a single rule. Read it that way and an oversized max_children stops looking like insurance.
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A test-environment check asked which process it was running in. The write it was supposed to block happened in a different process, once per headless login, for about a year.
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