[Exporter.Geneve] Will TlvMetricExporter support ExponentialHistogram?

[YanlingCui]

Hi Team,

Exponential bucket histogram aggregation achieves low relative error for histogram instruments. So, we want to apply Exponential histogram to our metrics. While we found the metric data cannot be exported to Geneva. It looks like TlvMetricExporter doesn't support ExponentialHistogram yet.

In our scenario, we send metrics to ETW through TlvMetricExporter.
We'd like to know do you plan to support ExponentialHistogram in TlvMetricExporter?

[Kielek]

@rajkumar-rangaraj, @xiang17, FYI

[harsimar]

Hi,
Can I ask if the intent behind this ask is to be able to transport exponential histograms through ETW?

If so, there is an alternative way around this. One could use this feature to send exponential histograms serialized in OTLP format over ETW. In addition to the change in connection string & resource attributes mentioned, one would also need to configure a part of the geneva pipeline to receive otlp over etw. I can send an example from internal docs over teams.

[YanlingCui]

Thank you @harsimar for the reply. Glad to know there is a work around to transport exponential histograms through ETW. I have several follow up questions:

1. This is an experimental feature. When will it be ready for production?
2. We have many production services using Geneva exporter to export metrics in our organization. The default TlvMetricExporter is used within GenevaMetricExporter. Is there any risk (like data correctness, performance issue) for us to switch to OtlpProtobufMetricExporter?
3. Will TlvMetricExporter support ExponentialHistogram or not? If not, we will have to start with OtlpProtobufMetricExporter.

[harsimar]

I am discussing with the team about this and will update when I have more concrete answers about points 1 & 3. As of right now, I am not aware of any risk/performance issue related to the preview feature.

[harsimar]

It is unlikely that this change will be made to the TlvExporter, as the future direction / intention is to use the OtlpProtobufMetricExporter when it goes to production. Please try out the preview feature, and for future help you can also try internal means of accessing support (office hours, etc).

[YanlingCui]

Thank you @harsimar for the reply. We really look forward to see the feature go production.