Abstract: Cloud computing needs to manage a large number of computing tasks, while task scheduling strategy plays a key role in determining the efficiency of cloud computing. It is an important issue how to allocate computing resources reasonably and schedule tasks run effectively which can reduce the complete time and cost of all tasks. A Time and Cost constraints Genetic Algorithm（TCGA） is proposed, through which, a better scheduling result not only shortens time, but also costs less. The simulation shows that TCGA is an efficient task scheduling algorithm in cloud computing by contrast with Time constraints Genetic Algorithm（TGA） and Cost constraints Genetic Algorithm（CGA）.

Key words: cloud computing, Genetic Algorithm（GA）, task scheduling, time, cost

摘要： 云计算通常需要处理大量的计算任务，任务调度策略在决定云计算效率方面起着关键作用。如何合理地分配计算资源，有效地调度任务运行，使所有任务运行完成所需的时间较短、成本较小是个重要的问题。提出一种考虑时间-成本约束的遗传算法（TCGA），通过此算法调度产生的结果不仅能使任务完成所需的时间较短，而且成本较小。通过实验，将TCGA与考虑时间约束的遗传算法（TGA）、考虑成本约束的遗传算法（CGA）进行比较，实验结果表明，该算法是云计算中一种有效的任务调度算法。

关键词: 云计算, 遗传算法, 任务调度, 时间, 成本