Install Prometheus, Grafana, and Monitoring Server

Installation

1. https://computingforgeeks.com/how-to-install-grafana-on-ubuntu-debian/
2. https://computingforgeeks.com/install-prometheus-server-on-centos-7/
3. https://computingforgeeks.com/how-to-monitor-linux-server-performance-with-prometheus-and-grafana-in-5-minutes/

4. https://www.howtoforge.com/tutorial/how-to-install-prometheus-and-node-exporter-on-centos-8/
5. https://medium.com/@shevtsovav/all-databases-on-the-eyes-postgres-exporter-prometheus-grafana-d4c4f749d6aa

Understanding

1. https://blog.pvincent.io/2017/12/prometheus-blog-series-part-1-metrics-and-labels/
2. https://povilasv.me/prometheus-go-metrics/

Troubleshooting
https://stackoverflow.com/questions/53906324/prometheus-postgresql-node-exporter-configuration

Edit Documentation in Wikipedia
1. Install Prometheus Server in Linux Ubuntu 18
2. Install Node Exporter in Linux Ubuntu 18 as Prometheus Client
3. Install Postgres Exporter in Linux Ubuntu 18 as Prometheus Client