Notifying when a server is offline based on when agents last added data to OMS

[Update 11/29/2017: This blog post series has been superseded by a solution built to visualize server and client information which is available at: https://www.catapultsystems.com/cfuller/archive/2017/11/28/updating-the-server-and-client-performance-solution-to-the-new-query-language/. Please note that query examples in this deprecated blog post are for the old query language and will not work in the current query language.]   The first part of this blog…