Improving correctness and failure handling in workflow management systems
Improving correctness and failure handling in workflow management systems
复制标题
提高工作流程管理系统的正确性和故障处理
DOI：
--
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
K. Ramamritham
中科院分区：
文献类型：
--
作者：
M. Kamath;K. Ramamritham
工作流管理系统（WFMS）促进了跨分布式节点的构成业务流程（工作流）的应用程序（步骤）的协同执行。最先进的WFMS对于处理工作流的各种正确性和故障处理要求没有足够的支持。由于访问共享资源的步骤之间存在依赖关系，会产生不同的正确性要求。如果处理不当，工作流中的步骤故障和系统故障可能会导致数据不一致。由于当前的WFMS使用集中式工作流控制架构，该架构很容易成为性能瓶颈，所以可扩展性也是一个问题。
在本论文中，我们已经开发了解决上述问题所需的概念和基础设施。为了处理工作流之间的依赖关系，我们已经开发了用于表达和处理工作流实例之间的互斥、相对顺序和回滚依赖要求的技术。为了处理工作流内步骤的故障，我们提出了一种新的机会主义方案，当工作流部分回滚并重新执行时，该方案避免了不必要的补偿和重新执行。为了处理系统故障，我们设计了合适的日志记录方案和协议。为了在满足不同的正确性和故障处理要求的同时实现可扩展性，我们已经增强了我们的技术，使其能够在并行和分布式工作流控制架构上工作。
为了实现上述概念，我们设计了一种工作流规范语言、一个两阶段编译器和一个基于规则的运行时系统。工作流设计者从全局资源数据库中指定工作流模式以及步骤所访问的资源。两阶段工作流编译器确定数据依赖关系，并将高级模式转换为一组统一的规则。运行时系统解释这些规则，并根据集中式、并行式和分布式工作流控制下的要求执行工作流。为了证明我们方法的有用性和实用性，我们已经实现了一个原型系统，该系统能够提供比最先进的WFMS更好的正确性、性能和功能。
A workflow management system (WFMS) facilitates the coordinated execution of applications (steps) that comprise a business process (workflow) across distributed nodes. State-of-the-art WFMSs do not have adequate support for handling various correctness and failure handling requirements of workflows. Different correctness requirements arise due to the dependencies between steps that access shared resources. Failure of steps in a workflow and system failures can cause data inconsistencies if handled improperly. Scalability is also a problem in current WFMSs since they use a centralized workflow control architecture that can easily become a performance bottleneck.
In this thesis, we have developed the concepts and infrastructure necessary to address the above issues. To handle dependencies across workflows we have developed techniques for expressing and handling mutual-exclusion, relative ordering and rollback dependency requirements across workflow instances. To handle failure of steps within a workflow, we have proposed a new opportunistic scheme that avoids unnecessary compensations and re-executions when workflows are rolled back partially and re-executed. To handle system failures we have designed suitable logging schemes and protocols. To achieve scalability while satisfying the different correctness and failure handling requirements, we have enhanced our techniques to work on parallel and distributed workflow control architectures.
To realize the above concepts, we have designed a workflow specification language, a two stage compiler and a rule-based run-time system. A workflow designer specifies the workflow schema and the resources accessed by the steps from a global database of resources. The two stage workflow compiler determines data dependencies and translates the high level schema into a uniform set of rules. The run-time system interprets these rules and executes the workflows in accordance with their requirements under central, parallel and distributed workflow control. To demonstrate the usefulness and practicality of our approach, we have implemented a prototype system that can offer better correctness, performance and functionality than state-of-the-art WFMSs.
DOI：
--
发表时间：
2004
期刊：
DBSJ Letters Vol.2,No.14
影响因子：
--
作者：
H.Xu;T.Furukawa
通讯作者：
T.Furukawa