Multiple DAGs dynamic workflow reliability scheduling algorithm in a cloud computing system

In order to solve the reliable scientific workflow scheduling problem for cloud computing, a dynamic of the RANK-Hierarchical algorithm is put forward which takes account of communication contention as well as supports task dependencies(CCRH). A communication contention model is first defined, as soon as the earliest completion of the primary and backup task is deduced. Besides, the executived processor is limited. We use the dynamic hierarchical method and calculate each DAG unfair degree factor for multiple DAGs scientific workflow. It can deal with the situation that multiple DAGs workflow comes at different times and there are various kinds of structure. Both the theory and experiments have proved that the algorithm can not only improve the scheduling fairness of multiple DAGs workflow but also shorten the average execution Makespan.