i.o.exporter.internal.http.HttpExporter : Failed to export spans. Server responded with HTTP status code 404. Error message: Unable to parse response

General
1

What I am trying ot achieve:

I am trying to send traces to grafana cloud tempo using http.

Show some code:

this code is using, but it is using GRPC:

@Bean
    public SpanExporter primaryOtlpGrpcSpanExporter() {
        return OtlpGrpcSpanExporter.builder()
                .setEndpoint("https://tempo-us-central1.grafana.net:443")
                .addHeader("Authorization", "Basic ODEwNzcxOm[...]xOQ==")
                .build();
    }

I would like to use http instead of GRPC.

Hence, I used:

 @Bean
    public SpanExporter primaryOtlpGrpcSpanExporter() {
        return OtlpHttpSpanExporter.builder()
                .setEndpoint("https://tempo-us-central1.grafana.net:443/v1/traces")
                .addHeader("Authorization", "Basic ODE[...]D0=")
                .build();
    }

Describe actual results:

With the Http exporter above, I am getting

2025-05-13T08:49:55.458+08:00 [question,,]  WARN 16994 --- [httptry] [grafana.net/...] [   ] i.o.exporter.internal.http.HttpExporter  : Failed to export spans. Server responded with HTTP status code 404. Error message: Unable to parse response body, HTTP status message:

Using this URL, I would get 405: https://tempo-us-central1.grafana.net:443

Describe expected result:

I would like to be able to send traces via Http protocol, and see the trace in Grafana cloud tempo.

Question:

What is the correct URL to send traces via http?

2

You’re seeing the 404 and 405 errors because Grafana Cloud Tempo does not support OTLP over HTTP, only OTLP over gRPC.

Straight Answer:

Grafana Cloud Tempo requires OTLP/gRPC. There is no HTTP endpoint for OTLP ingestion.

So this line is correct:

OtlpGrpcSpanExporter.builder()
    .setEndpoint("https://tempo-us-central1.grafana.net:443")

And this line is incorrect (will always fail):

OtlpHttpSpanExporter.builder()
    .setEndpoint("https://tempo-us-central1.grafana.net:443/v1/traces")

Why HTTP doesn’t work

  • The OTLP/HTTP spec defines sending traces to /v1/traces
  • But Grafana Cloud Tempo does not expose that endpoint
  • Grafana only listens for OTLP via gRPC

What you should do

Stick with this setup:

@Bean
public SpanExporter primaryOtlpGrpcSpanExporter() {
    return OtlpGrpcSpanExporter.builder()
        .setEndpoint("https://tempo-us-central1.grafana.net:443")
        .addHeader("Authorization", "Basic <your-token>")
        .build();
}

And do not use OtlpHttpSpanExporter — it won’t work with Grafana Cloud Tempo.

Summary

  • Correct protocol for Grafana Tempo Cloud: gRPC
  • Incorrect / unsupported: OTLP/HTTP
  • There is no working HTTP URL for sending OTLP traces to Grafana Cloud Tempo

Let me know if you need help setting this up with Spring Boot’s OpenTelemetry auto-config.