Understanding how your microservices based application is executing in a highly distributed and elastic cloud environment can be complicated. CNCF OpenTracing is a new standard to help provide observability within such an environment. With the help from Jaeger, an OpenTracing compatible distributed tracing system, we will show how instrumenting an application using the OpenTracing API can provide not only tracing information, showing the path of execution through a set of cooperating services, but also application metrics and contextualised logging information, to help diagnose problems in highly distributed applications.