如何使用nagios或munin从外部应用程序/服务器中查询统计信息

I have a couple of linux (ubuntu) servers that work together every night to do some heavy processing. Say. I have 2 worker servers and 1 big indexing server. The worker servers feed the indexing server. The indexing server operates under a high load (based on input it's getting from the worker-servers.) I have a couple of linux (ubuntu) servers that