--- topology_description: type: ReplicaSetWithPrimary servers: - &1 address: b:27017 avg_rtt_ms: 5 type: RSSecondary tags: data_center: nyc - &3 address: c:27017 avg_rtt_ms: 100 type: RSSecondary tags: data_center: nyc - &2 address: a:27017 avg_rtt_ms: 26 type: RSPrimary tags: data_center: nyc operation: read read_preference: mode: Nearest tag_sets: - data_center: nyc suitable_servers: - *1 - *2 - *3 in_latency_window: - *1