One or more resolution processes run concurrently with the synchronization process of each replica, in response to detection of one or more synchronization conflicts. Each resolution process works to resolve the conflict for a data object while the synchronization process continues to process other synchronization updates. After a conflict resolution has been determined, the conflict resolution is tested against current conditions of the local replica. If the conflict resolution is not stale, it is applied to the local replica and passed back to the synchronization process for propagation to remote replicas. Otherwise, if the conflict resolution is stale, it is discarded.