Servlets are removed from the service by the Web Container calling their destroy() method. This releases the instance of the servlet. There are different reasons for a servlet to be finalized - the application is about to be stopped, the servlet has thrown unavailable exception and so on.

The Web Container provides a timeout period before it actually calls the destroy() method of the servlet. This gives any long-running threads executing the service method of the servlet the opportunity to complete their work. The timeout is specified using the DestroyTimeOut property of the Web Container Service.