Correlating Go Logs and Traces

Manual injection

The Go tracer API allows printing span information along with log statements using the %v format specifier:

package main

import (
    "net/http"

    "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
)

func handler(w http.ResponseWriter, r *http.Request) {
    // Create a span for a web request at the /posts URL.
    span := tracer.StartSpan("web.request", tracer.ResourceName("/posts"))
    defer span.Finish()

    // Append span info to log messages:
    log.Printf("my log message %v", span)
}

The above example illustrates how to use the span’s context in the standard library’s log package. Similar logic may be applied to third party packages too.

Note: If you are not using a Datadog Log Integration to parse your logs, custom log parsing rules need to ensure that dd.trace_id, dd.span_id, dd.service, dd.env and dd.version are being parsed as strings. More information can be found in Correlated Logs Not Showing Up in the Trace ID Panel.

Further Reading

Additional helpful documentation, links, and articles:

Manually instrument your application to create traces.DOCUMENTATION more more Explore your services, resources, and tracesDOCUMENTATION more more Correlate request logs with traces automaticallyBLOG more more Ease troubleshooting with cross product correlation.GUIDE more more