如果一个应用程序池死了，该池服务的资源的下一个请求将自动重新启动它.但是，如果您在应用程序池上启用了快速故障保护，并且在 故障间隔 指定的时间间隔内，该应用程序池的死机次数超过了 maximum failures 属性指定的次数.em> 属性，那么您将收到 503 Service Unavailable 消息.此时，您将不得不手动重新启动应用程序池.

If an application pool dies, the next request for a resource served by that pool will automatically restart it. If, however, you have rapid fail protection enabled on the app pool, and the pool dies more times than the number specified by the maximum failures property within the interval specified by the failure interval property, then you will receive a 503 Service Unavailable message. At this point, you will have to manually restart the app pool.

要解决此问题，请禁用应用程序池的快速故障保护，或尝试增加时间段内的故障数量，然后确定导致应用程序池终止的异常的根本原因.

To work around this, either disable rapid fail protection for the app pool, or try increasing the number of faults within the time period, and then determine the root cause of the exceptions which are terminating the app pool.