Scheduling Strategy of Subtask Decomposed

The scheduling strategy of subtask decomposed (sub- DC) is presented in this article, which includes two parts. The first part is layered transaction of DAG (directed acyclic graph), which all subtasks are divided into different layers according to precedence relation; The second part is task assignation, in the first, min-min scheduling strategy is used to assign subtasks of one layer to each computer of system; after subtasks of one layer are assigned, load balancing strategy is used to dynamically adjusted system load, which makes use of character of subtasks decomposed and makes one layer subtasks are assigned better reason; then layer-by-layer subtasks are assigned using the same method. The Sub-DC not only makes subtasks of each layer be executed as quickly as possible, but also makes the application be executed in shorter time. The implement result shows that the Sub-DC is better than the level-by-level scheduling strategy (sub-Lev).