网络环境下实时协同设计并发控制策略

Concurrency control strategy for real-time collaborative design based on Internet

为解决传统并发控制方法中存在的死锁、夭折率和重起率高等问题,分析了网络环境下协同设计的特点,提出了实时更新并发控制系统模型,该模型能根据代理的数据要求生成复制事务,事务发生改变后其他站点能实时显示、实时读取有效数据。运用模糊逻辑分析方法计算操作优先权限的分配,以此保证网络协同用户在操作过程中的高并发率。提出一种面向对象的实时复制结构下基于优先权限的乐观并发控制协议,该协议保证在不同站点的同一对象的多个拷贝在各自只有单进程访问的情况下,这些复制及其他各操作在各站点的执行结果之间的一致性,每次对象的拷贝只复制发生改变的部分,而不是整个对象,降低了网络负担。

To resolve the problems of deadlock, frequent abortion and frequent restarting in traditional concurrency control, the characters of collaborative design based on network were analyzed and a prototype system of real-time updating concurrency control was proposed. The system created the replication operation according to required data. So, after the operation was modified, the other sites could show and abstract the real-time data and solid models. The Fuzzy Logics was utilized to priority assignment of transactions, which ensured the high concurrence ratio for collaborative clients. An Object-oriented Priority-based Optimistic Concurrency Control Protocol in real-time Replication structure (OPOCCPR) was developed. The protocol ensured the multi-copy of the same object at different sites to have the consistency of replication result, when these sites just had the single access course. Every time, the replication of object just copied the part modified, not the whole object, which reduced the loads of network.