title: Spring Cloud Sleuth different trace-ID integrate with Kafka
body: <p>I'm using Kafka for Asyng calls between microservices, and i'm using Spring Sleuth for logging. The logging is ok, but when there is a message from Microservice1 to Microservice2, the logging's messages have  different Trace-ID.  Don't they have to have the same trace-Id but a different SpanId? is there any special configuration?</p>