1. A method comprising: determining, using one or more computers, an original subset of a plurality of nodes, the original subset comprising nodes currently unallocated to a job, each node in the plurality of nodes comprising a switching fabric comprising a switch integrated on the card and allowing node to node communication during execution of a job; selecting a job from a job queue; executing the selected job using one or more processors of one or more nodes of the original subset; and determining that dimensions of the selected job are greater than a topology of the original subset; selecting one or more nodes from a second plurality of nodes, the second plurality being distinct from the original subset, each of the nodes in the second plurality of nodes comprising a switching fabric integrated to a card and at least two processors integrated to the card, wherein the selected one or more nodes from the second plurality are unavailable at the time of selecting; and adding the nodes selected from the second plurality to the original subset to satisfy the dimensions of the selected job after the nodes selected from the second plurality become available.