I suspect the answer is that the OpenMetrics spec does not mention exemplars on Summaries. https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#summary
I don't see any technical obstacle to attaching them in https://github.com/prometheus/client_golang. Inside Prometheus, Summaries are just two metrics, so no special handling required. Bryan On Thursday, 6 October 2022 at 16:45:29 UTC-5 [email protected] wrote: > Hi, > > Great question from the CNCF Slack: What's the reason why we don't allow > Exemplars for _count in Summary metrics? > > Use case: Java's Micrometer provides a Summary with just a _count and a > _sum as the default metric for HTTP services. The _count has the HTTP > status code as a label, so these metrics are great for request rates and > error rates (and for average latencies if you have nothing better). > > However, there's currently no way to have exemplars. It would be nice to > have them, for example for investigating erroneous calls. If the _count was > an explicit counter, and not part of a summary, Exemplars would be > supported. > > What do you think? Any reason why Exemplars don't work in _count in > Summaries? Would that be something we could consider supporting? > > Fabian > -- You received this message because you are subscribed to the Google Groups "Prometheus Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-developers/34b54e23-51dc-4cfb-b00a-fc36a8d8c1bdn%40googlegroups.com.
