| Reason String | Text in HTTP.sys Error Log | Cause(s) of Error | ||||||||
Service unavailable. | N/A |
| ||||||||
Too many users. | ConnLimit | The connection limit for the site or server as a whole has been reached. | ||||||||
Application taken offline. | AppOffline | The application pool has been put into Rapid Fail Protection and has been disabled automatically. | ||||||||
Application request queue full. | QueueFull | The application pools request queue has been exceeded and the request cannot be queued. | ||||||||
Administrator has taken application offline. | Disabled | The administrator has stopped the application pool. | ||||||||
Application automatically shut down due to administrator policy. | AppShutdown | The application pool has been shut down because it exceeded its CPU usage limit. | ||||||||
Request timed out in app pool queue. | AppPoolTimer | The application pool is too busy to handle the request. The request has, therefore, timed out in the queue and has been returned with a 503 error. |
