Simulation of a computational job using various sets of resources, and potentially also the automated or semi-automated allocation of an appropriate set of resources for accomplishing a computational job comprising multiple vertices. For each of multiple potential sets of resources, a simulation module simulates processing of the computational job. While the simulation does not actually perform the vertex on each processing node, the simulation does use dependencies between vertices, and historical data regarding the processing of instances of such vertices, in order to determine the efficacy of processing of each vertex, and to put the estimations together into an overall simulation result.