yammer/telemetry — pull request #8 by leapingfrogs (2014-06-26 00:07:59+00:00)
Title: Introduce Enabled and Disabled Spans

To support tracing only when we have an incoming traceId and spanId and ensure calls to other services don't add those even when they weren't on the incoming request.

This allows us to ensure we avoid excess noise in the initial trace logs.