In this last example, we will discuss a technique that is not, strictly speaking, a functionality commonly provided by distributed tracing systems, but rather a side effect of the distributed context propagation mechanism that underlies all tracing instrumentation and can be relied upon in applications instrumented for tracing. We saw an example of this earlier when we discussed an implicit propagation of the frontend request ID used to tag transactions that were blocking in a mutex queue. In this section, we will discuss the use of metadata propagation for resource usage attribution.
Resource usage attribution is an important function in large organizations, especially for capacity planning and efficiency improvements. We can define it as a process of measuring the usage of some resource, such as CPU cores, or disk space, and attributing it to some higher-level business parameter, such as a product or a business line. For example, consider a company that has two...