Connect Node.js trace data with logs for Splunk Observability Cloud

You can configure Node.js logging libraries to include tracing attributes provided automatically by the Splunk Distribution of OpenTelemetry JS. Use the trace metadata to correlate traces with log events and explore Node.js application logs in Splunk Observability Cloud.

You can configure Node.js logging libraries to include tracing attributes provided automatically by the Splunk Distribution of OpenTelemetry JS. Use the trace metadata to correlate traces with log events and explore Node.js application logs in Splunk Observability Cloud.

Supported logging libraries

The Splunk Distribution of OpenTelemetry JS automatically supports the following logging libraries:

  • Bunyan

  • Pino

  • Winston

Activate logs injection

Log injection is already activated for the supported libraries. To inject trace data into formatted logs, see the documentation for each library.

Include trace metadata in log statements

The Splunk Distribution of OpenTelemetry JS provides the following attributes for logging libraries:

  • Trace information: trace_id, span_id, and trace_flags

  • Resource attributes: service.name, service.version, and deployment.environment as service.environment

The format of each log message depends on the library. The following is a sample log message formatted using Pino:

{"level":30,"time":1979374615686,"pid":728570,"hostname":"my_host","trace_id":"f8e261432221096329baf5e62090d856","span_id":"3235afe76b55fe51","trace_flags":"01","url":"/lkasd","msg":"request handler"}

Configure Filelog receiver for log export

After adding the span_id and trace_id attributes to the logs using supported logging libraries (e.g., Bunyan, Pino, Winston), you need to configure the Filelog receiver in the OpenTelemetry Collector to forward these logs to the Splunk Observability Cloud backend.

For details, refer to the official Filelog receiver documentation.