IIS 8-HTTP错误503。服务不可用

Question

I host my website in a Windows server 2012 (IIS8) environment. It was running successfully for the last couple of months but on two occasions recently the application pool crashed. When we tried to access the website it displayed an error of "HTTP Error 503. The service is unavailable". After we restarted the application pool the issue went away. Is this some kind of Windows patching issue or something else?

Answer 1

Have a look in the Event Viewer's Application log, for ASP.NET 'error', 'warning' and 'critical' events that happened around the time the web site stopped working. These should give you some idea as to why it shutdown the w3wp process.

The default setting for the application pool 'Rapid Fail Protection' allows for 5 failures in 5 minutes. You could change this to something less strict, eg allow 20 failures in 2 minutes. There's also a field called 'Shutdown Executable' where you can put a script that runs when the app pool is shutdown. I've known people to put a cmd file / script that re-starts the application pool in here, so the website gets re-started automatically after the crash. Obviously you need to think about the ramifications of doing something like this. But if the errors that cause the w3wp to crash are not, in your opinion, too severe you might want to try this.