一个有状态操作系统服务的范例。
OperatingSystem.ear: a sample stateful operating system service.
推荐——提供这样一些机制，即推荐和构建将系统返回到健康状态所需的操作。
Recommend - to provide mechanisms that recommend and build actions needed to return the system back to a healthy state.
最后，底层操作系统必须处于良好的状态才能支持应用程序。
Finally, the underlying operating system must be in good health to support the applications.
应用推荐