Title
Time-Optimal Construction of Overlay Networks
Abstract
ABSTRACTWe show how to construct an overlay network of constant degree and diameter O(log n) in time O(log n) starting from an arbitrary weakly connected graph. We assume a synchronous communication network in which nodes can send messages to nodes they know the identifier of and establish new connections by sending node identifiers. If the initial network's graph is weakly connected and has constant degree, then our algorithm constructs the desired topology with each node sending and receiving only O(log n) messages in each round in time O(log n), w.h.p., which beats the currently best O(log3/2 n) time algorithm of [Götte et al., SIROCCO'19]. Since the problem cannot be solved faster than by using pointer jumping for O(log n) rounds (which would even require each node to communicate Ω(n) bits), our algorithm is asymptotically optimal. We achieve this speedup by using short random walks to repeatedly establish random connections between the nodes that quickly reduce the conductance of the graph using an observation of [Kwok and Lau, APPROX'14]. Additionally, we show how our algorithm can be used to efficiently solve graph problems in hybrid networks [Augustine et al., SODA'20]. Motivated by the idea that nodes possess two different modes of communication, we assume that communication of the initial edges is unrestricted. In contrast, only polylogarithmically many messages can be communicated over edges that have been established throughout an algorithm's execution. For an (undirected) graph G with arbitrary degree, we show how to compute connected components, a spanning tree, and biconnected components in time O(log n), w.h.p. Furthermore, we show how to compute an MIS in time O(log d + log log n), w.h.p., where d is the initial degree of G.
Year
DOI
Venue
2021
10.1145/3465084.3467932
PODC
Keywords
DocType
Citations 
Distributed Protocol, Peer-to-Peer Network, Randomized Algorithm, Expander
Conference
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Thorsten Götte101.01
Kristian Hinnenthal242.17
Christian Scheideler31729152.71
Julian Werthmann400.34