Regarding "What operating systems are supported?" and the answer of "scout_realtime relies heavily on the proc file system to fetch metrics. procfs is supported on most Linux-based distributions with the exception of OSX and Debian."
procfs is available on my Debian 7 servers, so scout_realtime just installed and runs fine on the few that I've tried it on.
procfs is available on my Debian 7 servers, so scout_realtime just installed and runs fine on the few that I've tried it on.