What an Overloaded PHP Server Actually Returns

Mon, 24 Aug 2026 19:40:00 -0700

Ask most people what their PHP server does when it’s overloaded and you’ll hear “it returns 503s.” Ask them how they know and it usually comes down to a config setting they read about. I was in that camp for ePHPm. We had a [server.limits] max_connections knob, and the docs said it returned 503 at the cap. Every benchmark we had ever run reported zero errors under heavy load. Then I wrote a load generator that could produce overload. The honest answer was that an overloaded ePHPm returned nothing at all.

Load-Testing on Luther Monson

What an Overloaded PHP Server Actually Returns