PROMETHEUS
Prometheus Architecture
Prometheus discovers targets to scrape from service discovery. These can be your own instrumented applications or third party
https://pierrevincent.github.io/2017/12/prometheus-blog-series-part-1-metrics-and-labels/
https://pierrevincent.github.io/2017/12/prometheus-blog-series-part-2-metric-types/
Note: Vendor neutral APIs and instrumentation - http://opentracing.io/documentation/pages/quick-start