关键词: 事务模型, pivot事务, 调度算法, 事务补偿, Web服务组合

Abstract: The Web service composition transaction has the characteristic of long execution period, and a global transaction can be divided into multiple distributed sub transactions. Each sub transaction has different significance for the global transaction, as the success or failure of the key sub transaction’s execution will directly lead to the success or failure of the global transaction. On the other hand, some failed transactions have to be compensated, while executing too much compensating transactions will bring huge compensation cost. In the aim of solving these problems, this paper proposes a nested transaction model based on the pivot transaction, and divides transactions in the model into the pivot transactions and the non-pivot transactions, the model contains at least one pivot transaction. And based on this model, this paper presents a pivot transaction priority scheduling (PTPS) algorithm to reduce the number of compensating transactions that is needed to execute while the pivot transaction fails and reduce the compensation cost, by giving priority to execute the pivot transaction.

Key words: transaction model, pivot transaction, scheduling algorithm, transaction compensation, Web service composition