确认空闲超时未设置在IIS应用程序池。该设置的默认值是20分钟（这会导致混乱超时是否由会话超时或空闲超时触发），在大多数情况下，可以安全地设置为0，将其关闭。

Make sure the idle timeout isn't set on the app pool in IIS. The default for that setting is 20 minutes (which leads to confusion over whether the timeout was triggered by session timeout or idle timeout) and in most cases can be safely set to 0, which turns it off.

要检查IIS中的空闲超时，进入高级设置的应用程序池。

To check the idle timeout in IIS, go to Advanced Settings for the app pool.

空闲超时是基于应用程序的活动滑动窗口，因此从任何客户端请求将重置窗口。如果您的应用轻易使用，你会频频命中超时，导致您的应用程序池回收。对用户的影响是，这已经积极将丢失任何会话，用户步行到您的应用程序已空闲之后将不得不等待它运行所有的启动过程。

The idle timeout is a sliding window based on activity for the app, so requests from any client will reset the window. If your app is lightly used, you'll hit the timeout frequently, causing your app pool to recycle. The impact to users is that any sessions that had been active will be lost, and users walking up to your app after it has been idle will have to wait for it to run all of its start up processes.