An integer programmimg approach for assigning votes in a distributed system

Voting is a general approach to maintain consistency of replicated data under node failures and network partitions. In voting, each node as assigned a particular number of votes, and any group with majority of votes can perform operations. Votes assigned to the nodes have a significant impact on the performance of a voting system. In this report, we propose an integer programming approach for determining the vote assignment for maximizing the throughput. We use Monte-Carlo simulation to find the most likely groups formed due to partition failures and use these groups to formulate vote assignment as an integer programming problem. We have developed a tool called vote assignment tool (VAT) that implements this approach. VAT takes as input the configuration of the network, and after formulating the problem as integer programming exercise, solves it to output a vote assignment. We have tried this approach for different networks and have found that in many cases this approach assigns votes equivalent to or better than the best vote assignment given by the various heuristics.