Prometheus remote write exporter implement v2

[jmichalek132]

Component(s)

exporter/prometheusremotewrite

Is your feature request related to a problem? Please describe.

Prometheus remote write v2 spec is close to being finalized, it would be good time to start working on implementing support for it in the prometheus remote write exporter component. Soon backend such as prometheus, mimir, thanos etc will start supporting it. It would great to start working on implementing to gain it's benefits,.

Describe the solution you'd like

I would like to contribute implementation of the remote write v2 prometheus/docs#2462 into the prometheus remote write exporter, most likely behind a feature flag since long-term v2 version is supposed to replace the current implementation.

Describe alternatives you've considered

Potentially it could introduced as a separate component but I hope that won't be necessary.

Additional context

The current implementation of remote write v2 lives in it's own branch of prometheus, https://github.com/prometheus/prometheus/tree/remote-write-2.0 , but should be merged soon.

TODO

Translation layer:

• Support for metadata
• Handle conflicts in metrics handle conflits in prw v2 #39570
• Handle target_info
• Handle exemplars
• Support for metric types
  • MetricTypeSum feat: add support for MetricTypeSum #37156
  • MetricTypeHistogram
  • MetricTypeExponentialHistogram
  • MetricTypeSummary

Exporter:

• Get initial PR merged http://github.com/open-telemetry/opentelemetry-collector-contrib/pull/38235
• Implement batching
• Sort timeseries [exporter/prometheusremotewrite] feat: prom rw exporter add support for rw2 #35888 (comment)
• Add test case with invalid proto message [exporter/prometheusremotewrite] feat: prom rw exporter add support for rw2 #35888 (comment)
• Go over the spec and confirm it follows it
• Optionally add e2e tests?

[github-actions]

Pinging code owners:

• exporter/prometheusremotewrite: @Aneurysm9 @rapphil

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[crobert-1]

Thanks for the proposal @jmichalek132, makes sense to me. Agreed that a feature gate is a good idea here. 👍

[varshith257]

Interesting! How can I contribute to this feature? @crobert-1 ,@jmichalek132

[rapphil]

Remote write 2.0 is still experimental in prometheus, however it will be enabled by default in the the upcoming version version 2.54.0.

Having said that I would welcome a contribution that will add support to PRW2.0. I think we can add a configuration option protocol_version that can be used by users to select what version of the remote write protocol they want to use. Valid values would be 1.0 and 2.0 with default value 1.0. Once Prometheus deprecate 1.0 we can plan on moving the default to 2.0.

[varshith257]

Thanks @rapphil . Will look into the Prometheus remote write 2.0 and plan the changes with above said

[dashpole]

cc @ArthurSens
We were considering making this a CNCF intern project: cncf/mentoring#1281