基于优先级和任务共享的工作流负载平衡研究

Load-balancing of workflow system based on priority control and task share

为了适应电子商务中迅速变化的流程环境和系统负载,需要在多个工作流引擎中分配工作量,以保证工作流引擎在高负载条件下可以保持一个可接受的性能。基于中间件技术的工作流负载平衡子系统是提供高可信赖性和高伸缩性的一种有效方法,但目前还存在许多不足,如没有从优先级的角度来区分流程,没有精确定义系统的负载,分析了工作流的主要特点,设计了基于优先级队列的,实现任务共享的,自适应负载系统,并通过实验定义了一个综合考虑系统处理能力和工作流负载特点的因子,这种设计已经在中科院软件所软件工程中心研制的OncePI工作流系统中得到实现,并在实际运用中检验了其可用性。

In order to accommodate to the fast change of process environment and workload of the E-business system, it is necessary to assign the Workload in multi-workflow engineer to ensure an acceptable performance on heavy workload. The workflow load balance subsystem based on the middleware technology is an effective method to offer the high-reliability and the high-flexibility, however, there are still some shortages existed in this method, such as not distinguishing the flow according to different priorities, not accurately defining the load of the system, and so on. The main characteristic of the workflow is analyzed, the adaptive load-balancing middleware which based on the preferred alignment is designed, and the service-sharing is realized. A load index is defined which can consider the disposal capability of the system and the characteristic of the wotkflow load synthetically via some experiments. This design is implemented in the OncePI system developed by us, and its usability is also proved in the actual usage.