Your pm.max_children Math Is Wrong: Why Averages Kill Production Stability

The article argues against using average worker memory to calculate PHP-FPM's pm.max_children, recommending P95 RSS under peak traffic with a 1.2x safety factor instead. It explains how average-based sizing leads to OOM kills and swap during traffic spikes, and covers the differences between VSZ, RSS, and PSS memory metrics for accurate capacity planning.