DevOps with Kubernetes - Second Edition

Working with PromQL

PromQL has three data types: instant vectors, range vectors, and scalars. An instant vector is a time series of data samples; a range vector is a set of time series containing data within a certain time range; and a scalar is a numeric floating value. Metrics stored inside Prometheus are identified with a metric name and labels, and we can find the name of any collected metric with the drop-down list next to the Execute button in the expression browser. If we query Prometheus using a metric name, say http_requests_total, we'll get lots of results, as instant vectors often have the same name but with different labels. Likewise, we can also query a particular set of labels using the {} syntax. For example, the query {code="400",method="get"} ...