[bug] OtlpExportProtocol.HttpProtobuf does not work

[domholmes]

Package

OpenTelemetry.Exporter.OpenTelemetryProtocol

Package Version

Runtime Version

net8.0

Description

Traces stop being exported when changing the protocol from gRPC to HttpProtobuf.

Steps to Reproduce

1. Create a sample app that exports to the gRPC endpoint of an APM
2. Run the application and verify data appears in the APM
3. Change the protocol to HttpProtobuf and update the port to the APM's Http port
4. Run the application again

Expected Result

Data continues to appear in the APM

Actual Result

Data stops appearing in the APM

Additional Context

Tested with both Jaeger and New Relic. Both work as expected with gRPC.
OtelLogTest.zip

[rajkumar-rangaraj]

You might have missed adding /v1/traces to the endpoint when using HttpProtobuf. For example:

opt.Endpoint = new Uri("http://localhost:4318/v1/traces");

This path is not needed when using gRPC.

Doc link - https://github.com/open-telemetry/opentelemetry-dotnet/tree/main/src/OpenTelemetry.Exporter.OpenTelemetryProtocol#otlpexporteroptions

[domholmes]

You might have missed adding /v1/traces to the endpoint when using HttpProtobuf. For example:

opt.Endpoint = new Uri("http://localhost:4318/v1/traces");

This path is not needed when using gRPC.

Doc link - https://github.com/open-telemetry/opentelemetry-dotnet/tree/main/src/OpenTelemetry.Exporter.OpenTelemetryProtocol#otlpexporteroptions

Ahhhh, this works. Thanks.