A common monitoring target is the number of concurrent users in a web application. A possible solution is to have a scheduled background task, which once a minute queries the appropriate resource and sends us the current number of users. This metric is given an appropriate identifier, for example conc_users. Each time we receive a message with a metric (or metrics), we store the values with the current timestamp (or a timestamp that you can optionally include). When you create a new Grafana dashboard, you can start graphing this newly available metric with just a few clicks:
Although it lets you get up and running quickly with simple graphs, Grafana is a very powerful tool. You can build complex graphs featuring multiple metrics, with transformations on that metric data - as well as being able to fine tune the styling of the graph.
Here’s another example: this time three metrics are being graphed simultaneously, and some styling has been applied to improve clarity. Check out the Grafana graphs panel reference for some of the many available possibilities.