Run the Jobs
You have built the graph by executing the "tools" (emulated by cp) interactively under the control of the vw wrapper. By using that wrapper, you have established runtime tracing. With runtime tracing turned on, FlowTracer discovers the inputs and outputs at runtime as the program is run. It builds a dependency graph of the files related to the program. The flow holds a data set that defines the dependency graph, the jobs, and the current state of files. FlowTracer is now ready to execute the jobs in the flow, based on the dependency graph and the state of files in the system. It can schedule and deploy jobs that need to be run because they use an input file that has changed. This process is called "retracing".