Taskflow for task building?

Taskflow is a library that provides a reliable, resumable, revertable way to run tasks by taking advantages of pieces of the taskflow library to do this.

It appears that rally runs a set of 'tasks' in a series and the result of these tasks are a set of benchmarks (or the combination is a benchmark). It would be neat if taskflow was used to run the series of tasks (in taskflow terminology this is a 'flow') that form a benchmark, one could even imagine that there would be small modules 'files/entrypoints' that would define a 'make_benchmark()' method and rally would invoke that method and then using taskflow would run and capture whatever set of tasks were ran; this would form a single benchmark.

This would allow for easily creating new benchmarks (by combining various tasks together) as well as allow for correctly undoing the results of those benchmarks (as taskflow makes sure that a task like create_vm if it fails the reverting method gets called). This will ensure that rally doesn't leave any resources in a lost state.

Main page: https://wiki.openstack.org/wiki/TaskFlow

Examples: https://github.com/stackforge/taskflow/tree/master/taskflow/examples