Synchronization in Distributed Systems
Synchronization in Distributed Systems
复制标题
分布式系统中的同步
DOI：
10.1007/978-3-642-31513-8_43
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
C. Tripti
中科院分区：
文献类型：
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作者：
A. Sampath;C. Tripti
在目前的情况下，需要高度可靠和同步的系统。因此，从集中式系统逐渐转向分布式系统。这个系统也有一些缺点。最重要的一点是，在分布式系统中，不同的节点使用本地时钟来维护自己的时间，并且它们的时间值对于不同的节点可能不相同。也就是说，系统中没有全局时钟，因此分布式环境中的各种活动可以同步。系统中的各种时钟即使在瞬间被设置为公共时间值，也会由于不可避免的原因而漂移。因此，需要某种连续的同步机制，以便它们能够协调并一起工作，以实现分布式系统的目标。两种类型的同步是可能的-外部同步和内部同步。在真实的时间场景中，系统彼此同步并且与公共外部参考时间同步是重要的。这称为外部同步。但是在某些系统中，仅需要系统中的节点彼此同步。这称为内部同步。在许多应用中，事件的相对顺序比实际物理时间更重要。这里事件排序是在没有时钟时间值的情况下完成的。因此，取决于应用的区域和类型，所使用的时钟同步技术不同。
In the present scenario, a demand for the highly reliable and synchronous systems is seen. As a result, there has been a gradual shift to distributed systems from the centralized systems. There are few disadvantages for this system too. The most important one is that in a distributed system, the different nodes maintain their own time using local clocks and their time values may not be same for the different nodes. I.e. there is no global clock within the system so that that the various activities in the distributed environment can be synchronized. The various clocks in the system even if set to a common time value at an instant, drift apart due to unavoidable reasons. Hence some kind of continuous mechanism for synchronization is needed so that they can coordinate and work together to achieve the objectives of the distributed system. Two types of synchronization are possible- external synchronization and internal synchronization. In a real time scenario, it is important for the system to be synchronous with each other and with a common external reference time. This is called external synchronization. But in certain systems, it is only necessary for the nodes in the system to be synchronized with each other. This is called internal synchronization. In many applications, the relative ordering of events is more important than actual physical time. Here event ordering is done without clock time values. Hence, depending on the area and type of application, clock synchronization techniques used differs.