Java Metrics Documentation could use an update

[jaydeluca]

I would like to re-write the Java Metrics documentation to follow a format similar to other languages, and include missing information on Exporters, Readers, and Views.

What needs to be changed?

The current java instrumentation -> metrics documentation is missing a lot of information. As a new user who wants to start using java OpenTelemetry metrics, there is not enough information provided on this page to actually get started. Right now it only provides a brief introduction to the different instrument types supported, with very basic code examples.

Other languages like Go, C++ and Javascript follow a more in depth and organized structure / content that cover several things that the current java documentation doesn't include.

I plan to re-write this section of the java documentation to follow the structure of:

• Intro
• Initialize Metrics (MeterProvider)
• Acquiring a Meter
• Using Counters
• Using UpDown Counters
• Using Histograms
• Using Observable (Async) Counters
• Using Observable (Async) UpDown Counters
• Using Observable (Async) Gauges
• Adding Attributes
• Metric Views

Path of the page that needs changed?

https://opentelemetry.io/docs/languages/java/instrumentation/#metrics

Additional Context / Notes

I wasn't sure if I should open this issue in the opentelemetry-java repo or this one, if I need to do anything else before contributing this change, please let me know.

[svrnm]

Hey @jaydeluca, thanks for raising this issue and offering your help, this is the right place to ask for this (although I cc @open-telemetry/java-approvers for visibility).

Please go ahead and provide these updates to the Instrumentation Documentation, all I ask you to do is use the JavaScript and other documentation that is already in place as a blueprint for your additions. We try to create consistent documentation across languages right now, such that most of the non-code part of the documentation is the same, see
#3229

[trask]

yes ❤️❤️❤️

[breedx-splk]

Came here to also say thanks @jaydeluca ❤️