As you decompose your services into multiple containers, one of the hardest things to understand is the flow and path of requests, and how containers are interacting. As you expand and use more containers to support components within your system, knowing which containers are which and how they're contributing to the performance of a request becomes a significant challenge. For simple systems, you can often add logging and get a view through the log files. As you move into dozens, or even hundreds, of different containers making up a service, that process becomes far less tenable.
One solution to this problem is called Distributed Tracing, which is a means of tracking the path of requests between containers, much like a profiler can track requests within a single application. This involves using libraries or frameworks that support a tracing library to create and pass along the information, as well as a system external to your application to collect this information...