Failed to export spans. Agent tries to connect to localhost:4318

[yefisher]

Hey guys, I want to use agent to collect some application data and send it to Grafana.
I use external plugin for gradle to inject agent to the jib and run agent daemon alongside with my app. I use environment variables (e.g. OTEL_EXPORTER_OTLP_ENDPOINT) with my receiver endpoint which ends with 4317.
Application logs show that the agent starts and after few seconds I'm getting next error:
ERROR [OkHttp http://localhost:4318/...] ThrottlingLogger.java:82 - Failed to export spans. The request could not be executed. Full error message: Failed to connect to localhost/[0:0:0:0:0:0:0:1]:4318
Is there any known issue or am I doing it in a wrong way?
The version of the agent is 1.31.0

[laurit]

It is not a know issue. Most likely you are correct, you are doing something wrong, though it is hard to say what it is. 4318 is the port for http/protobuf protocol, while 4317 is for grpc, by default agent uses grpc.

[yefisher]

Most of the examples are quite simple and come down to simply launching the agent and specifying the corresponding environment variables, right? So I do the same using OTEL_EXPORTER_OTLP_LOGS_ENDPOINT, OTEL_EXPORTER_OTLP_TRACES_ENDPOINT and OTEL_EXPORTER_OTLP_METRICS_ENDPOINT environment variables. Logs, traces and metrics are written to the Grafana, but the stacktrace is full of mentioned error.

[yefisher]

Sorry for distracting you, logs are not propagated to the grafana, but metrics, traces and spans are good. Mentioned error still there.

[laurit]

By default agent does not enable exporting logs (this will change in the 2.0 version of the agent) you have to manually enable it by setting OTEL_LOGS_EXPORTER=otlp.
Having spans working is a bit surprising considering the error message you posted says Failed to export spans. Unless you provide a minimal application that reproduces the issue it will be hard to tell what causes this.

[yefisher]

Hi,
Thanks a lot, this solution helped me
But mentioned error in the root question still relevant

I have these variables to configure agent

[laurit]

I think these logs lines don't come from the otel java agent. Log lines from the agent are formatted slightly differently. Perhaps your application uses a library that configures its own opentelemetry sdk to send traces? For example micrometer tracing that is used in spring boot.

[yefisher]

Yeah, you're right!
This might comes from micrometer-tracing-bridge-otel
Thanks a lot for your time and tips.