 Hello, I'm Tim Sarowitz for the Linux Foundation. In today's text print, we're going to talk about Prometheus. Prometheus is a monitoring project that is part of CNCF. Let's start by going to Prometheus.io. Prometheus is a time series database which scrapes values from an instance. With a Go client library, you can easily instrument your own applications. The metrics also have libraries for Java, Python, and Ruby. The data is tracked by one of four metrics. A counter, which is monotonic, only increasing until reset, such as a total number of IOPS. Gauge, a value that goes up or down such as CPU utilization. Histogram, seeing the values over time compared to other activities can be very helpful. As a complex metric, it is used to track a number and the sum of values over time, which could produce a running average or other statistical value. Summary, similar to a histogram, but calculation is done on the client side, whereas histograms are calculated on the server. It cannot be aggregated, but can offer more accurate quantile. Collecting the data is the start. Making use of it is the next step. Visualization of the data can be done through an expression browser, implementing console templates, or, my favorite, Grafana dashboards. Walk into a startup in the Bay Area and the walls are covered with TVs, each with a different graph. Everyone knows the state of the enterprise at the moment, as well as a histogram of what's been happening recently. If something goes wrong, everyone can see it at the same time. This is agile business. You can find more about Grafana at github.com slash Grafana. If you scroll down, you'll notice that there is a play.grafana.org, where you can see a current iteration of Grafana and some of the different diagrams that are possible. This is pulling information from the Grafana people themselves. If you want to know more about Grafana and Prometheus, check out the LFS 241 class, Monitoring Systems and Services with Prometheus. If you look at the outline, you'll see you will cover everything from service monitoring and installing Prometheus to querying dashboards and more. Take a look.