1. A method of collectively loading an application in a parallel computer, the parallel computer comprising a plurality of compute nodes, the method comprising steps of: identifying, by a parallel computer control system, a subset of compute nodes in the parallel computer to execute a data processing job; selecting, by the parallel computer control system, one compute node in the subset of compute nodes in the parallel computer as a job leader compute node; retrieving, an application for executing the data processing job from a computer memory in the parallel computer and loading into a memory of the job leader node; performing, by the subset of compute nodes, a collective broadcast operation, including broadcasting, by the job leader compute node to the subset of compute nodes in the parallel computer, the application for executing the data processing job; and sending, from the parallel computer control system to the subset of compute nodes in the parallel computer, control information about the data processing job, wherein the control information comprises a particular path through the subset of compute nodes that messages should be passed, wherein the particular path is based on a message type.