How to use OpenTelemetry sink ?

[zyy17]

Notice that Vector already has OpenTelemetry Sink and try the following config:

sources:
  otel_traces:
    type: "opentelemetry"
    http:
      address: "0.0.0.0:4318"
    grpc:
      address: "0.0.0.0:4317"

sinks:
  store_traces:
    type: opentelemetry
    inputs:
      - otel_traces.traces
    # My OpenTelemetry traces the backend.
    # It will accept the protobuf encode traces data through HTTP.
    protocol:
      type: "http"
      uri: "http://localhost:4000/v1/otlp/v1/traces"
      method: post
      encoding:
        codec: "native"

Unfortunately, my trace backend can't parse the data. It seems the data have been transformed to another format in Vector.

My vector version is:

./vector --version       
vector 0.44.0 (aarch64-apple-darwin 3cdc7c3 2025-01-13 21:26:04.735691656)

Also, I can't find any documents that describe the example of opentelemetry. How can I use OpenTelemetry sink?

[pront]

Hey @zyy17, if I understand correctly you are doing OTEL traces -> OTEL traces via Vector. Upon receiving the log, the OTEL source will decode them into Vector events. Native codecs aren't supported yet, so those Vector events need to be remapped back into what the OTEL collector expects.

See example here:
https://vector.dev/docs/reference/configuration/sinks/opentelemetry/#how-it-works

[pront]

It should be doable yes by setting https://vector.dev/docs/reference/configuration/sinks/opentelemetry/#protocol.encoding.protobuf.

The tricky part is to shape the events properly before they hit the sink. The quickstart guide might be helpful: https://vector.dev/docs/reference/configuration/sinks/opentelemetry/#quickstart

[zyy17]

It seems not a better solution. Do you have a plan for supporting trace model directly(as opentelemetry collector)?

[pront]

Yes, we do plan to support it but it's unclear when we can get to it. Remap + Reduce is extremely powerful though, so I wouldn't discount it for now.

[zyy17]

Thanks for your answer. I still have two questions:

1. If I use vrl to transform a trace event to an otel format, how can I use protobuf encoding and send it as an http payload?

2. I am very interested in supporting trace exporter. How can I get more details about the plan? I already reviewed most of the issues related to the topic; however, it seems most of the issues are still WIP. Do you have any advice for contributing the code for this part?

[pront]

If I use vrl to transform a trace event to an otel format, how can I use protobuf encoding and send it as an http payload?

Remap will take in trace events and output traces events. As long as the output events conform to the opentelemetry trace proto then those should be accepted by the Otel collector.

I also recommended the reduce transform to aggregate traces since the collector supports an array of traces. But that can be thought of as an optimization.

I am very interested in supporting trace exporter. How can I get more details about the plan? I already reviewed most of the issues related to the topic; however, it seems most of the issues are still WIP. Do you have any advice for contributing the code for this part?

This is great! Which issues are you referring to?

One possible way is to support a proto conversion like we do in the source but it will be from Vector events to OTEL protos.

Don't hesitate to follow-up, happy to exchanges more ideas 👍