1. A method, comprising: storing a plurality of subgraphs of a directed acyclic graph (DAG) in a distributed storage system; processing a first subgraph of the plurality of subgraphs from the distributed storage system with associated input values in a computing device of a DAG distributed execution engine to generate first output values in a first iteration; storing a second subgraph in a cache of the computing device, wherein the second subgraph is a copy of the first subgraph; and processing the second subgraph with the first output values to generate a second output values if the computing device is to process the first subgraph in a second iteration that occurs after the first iteration.