论文标题
在周期上的动态平均负载平衡
Dynamic Averaging Load Balancing on Cycles
论文作者
论文摘要
我们考虑以下动态负载平衡过程:给定带有$ n $节点的基础图$ G $,在每个步骤中,在$ t \ geq 0 $中,创建一个单位负载,并放置在随机选择的图形节点上。在同一步骤中,所选节点选择一个随机的邻居,两个节点通过平均值来平衡其负载。我们对随着过程的进展以及其对$ n $以及图形结构的依赖性和图形结构的依赖感兴趣。 佩雷斯(Peres),塔尔瓦(Talwar)和威德(Wieder)研究了上述图形平衡分配过程的类似变体,以及索尔瓦尔德(Sauerwald)和太阳(Sun)的常规图。在\ emph {dynamic}情况下\ emph {cycle graphs}的情况下,这些作者留下了表征差距的问题,其中在算法的执行过程中创建了权重。在这种情况下,唯一已知的上限是$ \ Mathcal {o}(n \ log n)$的$,从佩雷斯,Talwar和Wieder引起的主要化参数之后,该参数分析了相关的图形分配过程。 在本文中,我们在上述$ n $的循环的上述过程中提供了$ \ mathcal {o}(\ sqrt n \ log n)$的上限。我们介绍了一种新的潜在分析技术,使我们能够在周期中限制$ k $ -HOP邻居之间的负载差,以限制任何$ k \ leq n / 2 $。我们使用一个“间隙覆盖”参数进行补充,该参数通过将差距的最大值界定在某个结构的所有可能子集中,并递归地界定每个子集中的间隙。我们提供了分析和实验证据,表明我们在间隙上的上限紧密到对数因素。
We consider the following dynamic load-balancing process: given an underlying graph $G$ with $n$ nodes, in each step $t\geq 0$, one unit of load is created, and placed at a randomly chosen graph node. In the same step, the chosen node picks a random neighbor, and the two nodes balance their loads by averaging them. We are interested in the expected gap between the minimum and maximum loads at nodes as the process progresses, and its dependence on $n$ and on the graph structure. Similar variants of the above graphical balanced allocation process have been studied by Peres, Talwar, and Wieder, and by Sauerwald and Sun for regular graphs. These authors left as open the question of characterizing the gap in the case of \emph{cycle graphs} in the \emph{dynamic} case, where weights are created during the algorithm's execution. For this case, the only known upper bound is of $\mathcal{O}( n \log n )$, following from a majorization argument due to Peres, Talwar, and Wieder, which analyzes a related graphical allocation process. In this paper, we provide an upper bound of $\mathcal{O} ( \sqrt n \log n )$ on the expected gap of the above process for cycles of length $n$. We introduce a new potential analysis technique, which enables us to bound the difference in load between $k$-hop neighbors on the cycle, for any $k \leq n / 2$. We complement this with a "gap covering" argument, which bounds the maximum value of the gap by bounding its value across all possible subsets of a certain structure, and recursively bounding the gaps within each subset. We provide analytical and experimental evidence that our upper bound on the gap is tight up to a logarithmic factor.