A fault-tolerant distributed sorting algorithm in tree networks

The paper presents a distributed sorting algorithm for a network with a tree topology. The distributed sorting problem can be informally described as follows: nodes cooperate to reach a global configuration where every node, depending on its identifier, is assigned a specific final value taken from a set of input values distributed across all nodes; the input values may change in time. In our solution, the system reaches its final configuration in a finite time after the input values are stable and the faults cease. The fault tolerance and adaption to changing input are achieved using Dijkstra's paradigm of self stabilization. Our solution is based on continuous broadcast with acknowledgment along the tree network to achieve synchronization among processes in the system; it has O(nh) time complexity and only O(log(n)deg) memory requirement where deg is the degree of the tree and h is the height of the tree.