netdata is a system for distributed real-time performance and health monitoring. It provides unparalleled insights, in real-time, of everything happening on the system it runs (including applications such as web, or database servers), using modern interactive web dashboards.
netdata is featured at GitHub's Status of the Octoverse 2016: https://octoverse.github.com/
I tried to visualize many system and application metrics with netdata. Demo: http://netdata.firehol.org/
Check it. It is good (warning: I wrote it, so I may be biased :).