So far in this Prometheus blog series, we have looked into Prometheus metrics and labels (see Part 1 & 2), as well as how Prometheus integrates in a distributed architecture (see Part 3). In this 4th part, it is time to look at code to create custom instrumentation. Luckily, client libraries make this pretty easy, which is one of the reasons behind Prometheus' wide adoption. This post will go through examples in Go and Java. Prometheus has a number of other supported languages, through offici...