Richer log outputs to be able to correlate otel traces and logs

[mastoj]

Goals

1. Ease production debugging
2. More insight into system performance

Non-Goals

No response

Background

Open telemetry consists of three core pillars, metrics, logs and traces. I understand that metrics might not relevant from a nextjs perspective since that is more a core infrastructure part. When it comes to logs and traces it should be an easy way to enrich what is logged and structure for easier correlation between logs and traces. What I would expect to see in logs when I have instrumentation on is my logs to contain span_id and trace_id, which would enable a lot of the otel providers out there to correlate the logs with my traces.

Proposal

I'm not 100% sure if this is really nextjs or if it is vercel specific to be honest. I will definitely contribute verifying, if time allows I can try to help out developing.

[aniruddhaadak80]

Hi @mastoj ,

Thank you for highlighting the need for richer log outputs in Next.js to enhance production debugging and system performance insight. Including span_id and trace_id in the logs would indeed facilitate better correlation between logs and traces when using OpenTelemetry.

To address this, I suggest the following steps:

1. Log Enrichment: Implement log enrichment to include span_id and trace_id in your logging configuration. This may require custom logging middleware that captures and formats these identifiers.

2. OpenTelemetry Integration: Ensure that your OpenTelemetry setup correctly propagates these identifiers through your application, which can typically be configured in the instrumentation settings.

Thanks .

[mmanciop]

Hi all,

I think the runtime logs emitted by Vercel through the log drains should include (either by default or opt-in) the trace_id and span_id if the OpenTelemetry tracing in Vercel is being used (https://vercel.com/docs/observability/otel-overview). This is not something that users would likely be able to duplicate on their own, especially for error scenarios (which are the most interesting).