Because XYZ can report what is going on inside the server, it is also appropriate for server debugging. For example, if a client exposes a rendering bug, xyztool could be used to see what rendering requests were performed when the bug was exposed.

The tracing functionality can also be used to track the flow of control through the server to expose bugs. But the author's experience is that the tracing functionality of XYZ has not been very useful. It is tedious to mask out the many unimportant tracing messages and requires careful examination of the trace to determine what happened.

Tracing remains a part of XYZ because it is cheap to add and may be beneficial for some uses.