Opentelemetry OTLP Structure

I’ve been finddling around with OpenTelemetery for a while, I wrote the SeanHood/laravel-opentelemetry package which used the Zipkin Exporter to get data out. However, recently Honeycomb.io added support for ingesting OTLP over GRPC nativly.

This support isn’t quite there yet opentelemetry-php#230 but I wanted to see how far off it was. Information/docs on this layer of OpenTelemetry is incredibly sparse, you’re mostly down to reading source code.

Anyway, in all of this I wasn trying to understand the structure of how a Span relates to an array of ResourceSpans so I came up with this psudocode:

ExportTraceServiceRequest(
    resource_spans: ResourceSpans(
        resource: Resource (
            attributes
        )
        instrumentation_library_spans: InstrumentationLibrarySpans (
            instrumentation_library: InstrumentationLibrary(
                name: 'my-instrumentation'
                version: '0.0.1'
            )
            spans: Span(
                span_id: 'xxx'
                trace_id: 'xxx'
                ...
            )
        )
    )
)

It might not be correct, let me know if I’m off but it helped me visualise what the protocol was expecting.

I figured this out by reading the opentelemetry-ruby source code ref. They aren’t there yet with GRPC but have things in place for OTLP/HTTP.