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随着多媒体和网络技术的发展,分布式交互系统被广泛应用.在这种系统中,多个客户端通过局域或广域网交互连接.为使响应时间短,本地节点产生的操作立即在本地执行,并广播到其他远程节点执行.在该系统中,一致性维护是一个关键问题,而文献中研究的一致性问题几乎都是基于不连续媒体的.通过一个实例,指出连续媒体中的一种不一致问题.虽然该问题可以通过绝对一致模型解决,但绝对一致模型应用在广域网中将导致长响应时间.为解决绝对一致模型中响应时间过长的问题,提出了延迟一致性模型(简称为DCM模型).在DCM中,如果节点i产生了作用于对象x上的操作,该操作到达远程节点后强行延迟一段时间并要求在统一规定的时间执行.通过该方法,对象x在其他远程节点上的状态将最终保持一致.DCM很灵活,因为不同的对象可以有不同的强行延迟时间.如果分布式交互系统建立在实时网络上,这种强行延迟时间将成为实时通信中实时消息调度的重要参数.
With the development of multimedia and network technology, distributed interactive systems are widely used.In this system, multiple clients are interconnected through local area network or wide area network.In order to make the response time short, local node generated operations are executed locally , And broadcast to other remote nodes for execution.In this system, consistent maintenance is a key issue, and almost all the consistency problems studied in the literature are based on discontinuous media.An example shows that one of the continuous media Inconsistency problem.While this problem can be solved by the absolutely consistent model, the application of the absolute consensus model in the WAN will lead to long response time.In order to solve the problem of the long response time in the absolute consistent model, a delay consistency model (referred to as DCM Model.) In DCM, if node i produces an operation on object x, the operation is forcibly delayed for some time after it reaches the remote node and requires execution at a uniform, specified time, by which object x is on the other remote node The state will eventually be consistent.DCM is very flexible, because different objects can have different forced delay time.If the distributed interaction The system is built on the real-time network, and such forced delay time will become an important parameter of real-time message scheduling in real-time communication.