Why when i set environment variable PHP_LSAPI_CHILDREN (any value) for phpLsapi external app, i get 503 error? Also i set Max Connections=25, Instances=25.
If you use PHP_LSAPI_CHILDREN, you should set it to match "Max Connections" and set "Instances" to 1. Should not use PHP_LSAPI_CHILDREN and "Instances" at the same time.