问题描述
我想知道是否有人可以用通俗易懂的方式解释分布式系统中事件的部分排序?另外,总订购额是多少?
我真的很感谢。我在网上浏览了所有内容,发现的只是定义部分排序和全部排序的数学方程式,但是在分布式系统中却没有。
非常感谢
总排序是一种定义序列中每个元素确切顺序的排序。 / p>
部分元素的部分排序是一种未指定每个项目确切顺序的排序,而是仅定义了某些元素之间的顺序相互依赖的关键项。
在分布式计算的上下文中,这些词的含义完全相同。分布式计算对这些术语的唯一意义在于,事件的部分排序比 total ordering 更为普遍。在本地单线程应用程序中,事件发生的顺序是完全隐式排序的,因为CPU一次只能做一件事。在分布式系统中,通常只协调相互依赖的那些事件的偏序,并让其他事件以它们发生的顺序发生。
示例,摘自注释:如果您有三个事件 {A,B,C}
,那么如果总是必须发生这些事件,则将它们完全排序按照 A>的顺序B> C
。但是,如果 A
必须在 C
之前发生,但您不必担心 B
发生,然后将它们部分排序。在这种情况下,我们可以说序列 A> B> C
, A> & B
和 B> > C
都满足部分排序
I was wondering if someone could explain in layman's terms what partial ordering of events are in a distributed system? Also, what is total ordering?
I would really appreciate this. I've looked all over the web and all I can find are mathematical equations defining partial and total ordering, but not in the context of a distributed system.
Thanks very much
Total ordering is an ordering that defines the exact order of every element in the series.
Partial ordering of elements in a series is an ordering that doesn't specify the exact order of every item, but only defines the order between certain key items that depend on each other.
The meaning of these words is exactly the same in the context of distributed computing. The only significance of distributed computing to these terms is the fact that partial ordering of events is much commoner than total ordering. In a local, single-threaded application, the order in which events happen is totally ordered, implicitly, since the CPU can only do one thing at a time. In a distributed system, you generally only coordinate a partial ordering of those events that have a dependency on one another, and let other events happen in whatever order they happen.
Example, taken from the comments: If you have three events {A, B, C}
, then they are totally ordered if they always have to happen in the order A > B > C
. However, if A
must happen before C
, but you don't care when B
happens, then they are partially ordered. In this case we would say that the sequences A > B > C
, A > C > B
, and B > A > C
all satisfy the partial ordering
这篇关于分布式系统中事件的部分排序的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!