The process closing time for the application pool DefaultAppPool has exceeded the limit of

The process that served the application pool 'DefaultAppPool' has been closed for longer than the limit.
The server often generates the "application pool" DefaultAppPool. The process shutdown time exceeded the limit. The process ID is '2068'. The error caused iis to be in a suspended state. It is understood that the IIS application pool is set. The solution is as follows:

Internet Information Services (IIS) Manager->Application Pool->DefaultAppPool->Right-click Properties
1, Recycle
1, Recycle Work Process (minutes): Selected , the value is 1740
2, the recycling work process (number of requests): not selected (originally set to 35000)
3, the work process is recycled at the following time: do not fill
4, consume too much memory when recycling Work process: no choice. (2, 3, 4 items may avoid the server response problem that may be caused by the forced recycling process when the amount of access is high, causing the iis suspended animation to not respond)
Second, performance
only select the idle timeout for 20 minutes. Nothing else is chosen. The maximum number of working processes in WEB Park is 1 (default). Note that the web garden must be kept at default. If you fill in more than one number, the background program of some website programs will not open or refresh.

The original request queue was limited to 4000 and is now unlimited.
Third, the operating status
the first two are used, is the original default settings. The startup time is limited to 90 seconds and the shutdown time is limited to 180 seconds.

The hook that starts the fast failure protection is removed!
In order to avoid the fact that there are many errors when there is no prompt, you can not turn off, just increase the protection scope of fast protection, for example, the number of failures is 50 times and the corresponding program is closed for 5 minutes.

"Close time limit of 180 seconds" is required, because the process is closed, the original is 90 seconds limit, is the default value, if the process is closed for more than 90 seconds, it is considered timeout, thus appearing: process is closed Time exceeds the limit log, so extending this time appropriately can avoid this kind of error

The second method:
Cause: The memory heap of the independent process is exhausted, IIS can not create more processes Workspace to handle
Workaround:
1. HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Services\\W3SVC
2. Create a new DWORD item under the Parameters key, the name is: UseSharedWPDesktop value is 1 Restart IIS
The third
problem has been solved, found that the database connection can not be released, do not know what the reason, the same code is good locally, there is a problem on the server side, and finally add the following statement in the connection string to solve the problem.
Pooling=true; MAX Pool Size=512;Min Pool Size=50;Connection Lifetime=30
The fourth type of
new application pool, different websites refer to different program pools.