OpenMetrics integration doesn't propagate the `# HELP` line

[giuscri]

When OpenMetrics metrics include an # HELP line, the Datadog integration seems to skip them instead of mapping them to the description fields of the metrics. Would you accept any contribution on such extension? Any pointer on how you'd like to have this solved?

[AAraKKe]

Hi @giuscri! Are you referring to the description of the metrics when looking at them in the Metrics Summary page? That is metrics metadata and is not submitted for integrations with the metrics themselves. The description you see in that page is obtained from the metadata.csv file in each of the integrations.

In the case of OpenMetrics integrations, that description normally comes from the HELP line but not necessarily, or not exactly the same, since in many cases that line lacks enough information to clearly states what the metric means within the scope of the integration itself. We normally do some editing on the description we want to show.

Let me know if I understood your question. If you find that some metric description is incorrect, we are 100% open to submit updates on the metadata.csv contents and review them.

Thanks!

[giuscri]

Not sure we're on the same page. I've set up the openmetrics integration for a workload exposing such metrics, using kubernetes annotations.

Thing is that while the metrics are correctly scraped by the Agent the description field of such metrics is empty.

[AAraKKe]

I got you, thanks for clarifying. Let me repeat it in a way I can translate it to a proposed requirement on our side:

• When using the OpenMetrics integration you have the ability of selecting which metrics you want to emit from the scraped metrics, or rename them if you need to.
• You would expect the description of the metric you can see in the Metrics Summary page to be populated by the # HELP line of the OPenMetrics data being parsed.
• You are seeing the description empty and think it would be automatically updated with that information.

My confusion came because I thought you were talking about any OpenMetrics based integration. There are plenty of integrations that use OpenMetrics endpoints and we define the description of the metrics we emit through the metadata.csv file. See KrakenD for example.

I don't think there is currently a binding that lets an integration send metric metadata through the agent. Implementing this is likely not just an update in here but needs to be an update in the agent itself (I would need to double check this). However, your point makes sense that if a user is running the OpenMetrics integration it would be good that:

• The user could define in the configuration a description fro each metric (in case the HELP string is empty or poorly describes the metric)
• If there is no description configured the HELP string is taken
• This is an opt-out feature in case the user does not want that extra traffic and is ok not having this description being sent to DataDog.

I can bring this up with the team. We are planning to do some maintenance work on several checks and the. OpenMetrics one is one of them and I can bring this into the discussion.

[AAraKKe]

Hey @giuscri after taking a deeper look at this, yes, we would need some updates on the agent itself to handle this usecase. Can you please contact support for a feature request for the OpenMetrics check? This would allow us to prioritize it internally and go through the proper channel.

I am closing the issue for now.