How can I access the TraceId generated by splunk-otel-collector within an ASP.NET web application?

Question

In the current project, I send application logs to Splunk, while the splunk-otel-collector is responsible for sending instrumentation logs to SignalFx. The problem is we use the CloudFrontID as a correlationID to filter logs in Splunk, whereas SignalFx generates and uses the TraceId for logging. I am currently facing challenges in correlating the application logs' correlationID with SignalFx's TraceId.

I tried to log the TraceId value in application logs using the "Serilog.Enrichers.Span" NuGet package. However, no values were logged in Splunk.

var loggerConfig =
    new LoggerConfiguration().MinimumLevel.ControlledBy(LogLevel)
        .Destructure.UsingAttributes()
        .Enrich.WithSpan(new SpanOptions
        {
            IncludeTraceFlags = true,
            LogEventPropertiesNames = new SpanLogEventPropertiesNames()
            {
                ParentId = "ParentId1",
                SpanId = "SpanId1",
                TraceId = "TraceId1",
                OperationName = "OperationName1"
            },
            IncludeBaggage = true,
            IncludeOperationName = true,
            IncludeTags = true,
        })
        .Enrich.FromLogContext();

How can I access the TraceId generated by the splunk-otel-collector within the ASP.NET web application (Framework version: 4.7.2)?

Answer 1

To inject trace context fields in logs, enable log correlation by setting the SIGNALFX_LOGS_INJECTION environment variable to true before running your instrumented application.

Reference: https://github.com/signalfx/signalfx-dotnet-tracing/blob/main/docs/correlating-traces-with-logs.md

After enabling this environment variable: SIGNALFX_LOGS_INJECTION, I was able to see the traceId values in Splunk.