Check_MK Werk 8243: Handle and display information about cached agent data in GUI

ID: 8243 Title: Handle and display information about cached agent data in GUI Component: cmc Level: 2 Class: New feature Version: 1.2.7i1 Check_MK now keeps track of the original age of information sent by the monitoring agents. This is useful if certain agent sections are not generated anew each time the agent is called but that are cached either locally on the agent or on the Check_MK server (using the <tt>persist</tt> section option). The sections in question need to declare the age and lifetime of the cached data in the section header, e.g. <tt>&lt;&lt;&lt;foobar:cached(1431431239:86400)&gt;&gt;&gt;</tt>. Check_MK parses this information and hands it over to the Check_MK Micro Core. The core uses that for a precise computation of the staleness and also makes it available for the Multisite GUI. The GUI in turn uses the point of time where the cached information has been created as the time of the <i>last check</i> instead of the last execution of Check_MK. In the details of a service you can see both the age and lifetime of the cached data. When using Nagios or another core the new information from the agents is simply being ignored an nothing changes.