The vulnerability of vote assignments

In a faulty distributed system, voting is commonly used to achieve mutual exclusion among groups of nodes. Each node is assigned a number of votes, and any group with a majority of votes can perform the critical operations. Vote assignments can have a significant impact on system reliability, and in this paper we study the vote assignment problem. To compare vote assignments we define two deterministic measures, node and edge vulnerability. We present various properties of these measures and discuss how they can be computed. For these measures we discuss the selection of the best assignment and propose heuristics to identify good candidate assignments.