A website on the server after the access to their structures, the website will appear Service Unavailable error, and then open the IIS manager view will find that the use of the site after the application pool is unusually feign death,
Encounter this problem when we need to immediately think of to check the system log files, the specific method is to right-click my computer management -- -- -- -- -- - -- -- -- -- click event viewer - application log as shown in figure

Here we will see a red error source is W3SVC - WP, double-click on which an error view detailed information will be found the following error

This picture screenshots of the error is caused by the safety dogs

This picture screenshots of the error is caused by the net4.0 loading problem

This picture screenshots of the error is caused by the pseudo static component loading problem

In the above three screenshots is the screenshot of part of the reason for this kind of problem, so when we see such an error after know what is due to the problems lead to pool suspended animation, since found the cause of the problem, then we will be according to the specific cause of the problem specific to deal with, this tutorial is mainly to guide you how to find the cause of the problem through the log file,