云计算环境下适于工作流的数据布局方法

云计算环境下的工作流管理系统，适合支持需要高效的计算性能和大规模存储的跨组织业务协作，在应急管理、供应链管理和健康医疗等领域具有广泛的应用前景.然而，在大量并发工作流实例的情况下，当工作流的任务需要不同位置的数据，特别是涉及客户端隐私数据时，如何有效地存放这些数据、优化数据传输就成为其中的挑战.为此，云计算环境下适于工作流的数据布局方法能够根据数据的隐私要求把数据存放到云端和客户端，并且在工作流运行时根据控制流动态地调整数据布局，减少数据传输.实验表明，该方法能够有效减少工作流运行时的数据传输.

A Data Placement Approach for Workflow in Cloud

Cloud-based workflow tools suit well for supporting dynamic and cross-organizational business collaborations that can be commonly found in scenarios such as emergency management, supply chain management, healthcare management, etc. However, in these scenarios, a large amount of concurrent workflow instances could involve a great deal of data. When one task needs data located in different places, especially for private data located in client, the data transfer becomes a challenge. To effectively place these data, the workflow manager must intelligently select the place in which these data including private data will reside. In this paper, an approach to data placement for workflow in cloud is proposed, which places the data on cloud-side or client-side according to the privacy requirements, and adjusts to the data placement according to the control flow to minimize data transfers. By integrating the approach into a workflow system, we can expect improvement in data transfer. Experiments show that the proposed approach can effectively reduce data transfers during the workflows execution.