Certain edges of a dataflow graph may not require checkpoints for synchronization. For example, referring again to FIG. 2, the edge 122 from the second computation operation (node 120 in the first execution engine 210 to the data transfer operation at node 150 in the first execution engine 210 may not have an assigned checkpoint value because both operations are executed on the same engine (i.e., the first execution engine 210). Likewise, the edge 142 from the data transfer operation at node 140 in the second execution engine 220 to the first computation operation at node 110 in the second execution engine 220 may not have an assigned checkpoint value because both operators are executed on the same engine (i.e., the second execution engine 220).
