Nagios

This example uses a predefined "ping" Nagios plug-in, which sends Internet Control Message Protocol ( ICMP) echo requests to determine if a host is responsive or not.

这个示例使用了一个预定义的“ping”Nagios插件，它将发送Internet控制信息协议（Internet Control Message Protocol，ICMP）回显请求以确定主机是否有响应。

Another healthy practice is to catch all exceptions and fall back to reporting UNKNOWN service status so that Nagios can manage notification of this fact appropriately.

另一个好的实践是捕获所有的异常，并后退以报告UNKNOWN服务状态，以便Nagios能够正确地管理有关这个情况的通知。

Nagios can also assume a service is down if it has not received notifications in some period of time.

如果经过一段时间还没有接收到来自某个服务的通知，Nagios还可以假定该服务已经停止。