Exporting logs

[maaramirezpi]

Hi!

First of all, thank you for the great work and effort put in this.

I've been using otel4s for the past weeks, and have successfully exported tracing and metrics. Curious about if there is a workaround to export logs as well, I've spent quite some time trying to make it work for logs with no success.

Some guidance/advices will be much appreciated.

Thanks!

[iRevive]

Hey! Which backend are you using? otel4s-oteljava?

[iRevive]

Which logging library are you using? You might need to configure the logging adapter:
sfl4j:
open-telemetry/opentelemetry-java-instrumentation#7723
open-telemetry/opentelemetry-java-instrumentation#8942

Log4j:
https://docs.honeycomb.io/send-data/logs/opentelemetry/sdk/java/

[maaramirezpi]

I'm currently using log4cats which uses slf4j, so I'll take a look to the links you added.

Is this something you have done in the past, any tips?

[iRevive]

To be honest, I've never used logs exporter. Please let me know if you make it work. We can add a documentation section afterward.

[bpholt]

In case it helps, we wrote our own logging SpanExporter to send logs via log4cats and serialize JSON using Circe (because the Jackson version that came with opentelemetry-exporter-logging-otlp was incompatible with the Jackson version used by another library on our apps' classpaths).

We use it with the OTel Java SDK via Natchez, but behind the Natchez facade, I think it should work the same way? The OTel Java SDK is initialized here; lines 45, 83, and 100 are relevant to the logging portion.

I know this isn't 100% what you're asking for but maybe it'll be helpful. Feel free to disregard if not 🙂

[maaramirezpi]

This is great, thank you all for the comments. I'll give it a try and come back to share my findings

[iRevive]

Hey @maaramirezpi. otel4s 0.14.0 includes the logs module.

Warning

The logging module is only for bridging logs from other logging frameworks into OpenTelemetry.
It is not a replacement for a full logging API.

You can use it to forward logs from the logging framework (e.g. scribe) into OpenTelemetry. Then they will be exported through OTLP alongside the metrics and traces.

Here is the documentation: https://typelevel.org/otel4s/instrumentation/logs.html.