Evaluation of replicas consistency characteristics in NoSQL databases

While using replication on NoSQL databases the problem of replicas agreement is appeared. It is manifested as follows: once the record is updated on the one node, data on others nodes become stale. Consistency level can be adjusted by parameters (N, W, R): N - count of nodes, on which the record will be replicated eventually (may be with some latency); W - count of nodes (replicas), on which data has to be written in fact (after this, an answer about operation success will be send to user; if W