OSProfiler provides a tiny but powerful library that is used by most (soon to be all) OpenStack projects and their python clients. It provides functionality to be able to generate 1 trace per request, that goes through all involved services. This trace can then be extracted and used to build a tree of calls which can be quite handy for a variety of reasons (for example in isolating cross-project performance issues). WWW: https://pypi.python.org/pypi/osprofiler