topology_description: type: Sharded servers: - &1 address: g:27017 avg_rtt_ms: 5 type: Mongos - &2 address: h:27017 avg_rtt_ms: 35 type: Mongos operation: read read_preference: mode: Secondary tag_sets: - data_center: nyc suitable_servers: - *1 - *2 in_latency_window: - *1