1{ 2 "heartbeatFrequencyMS": 10000, 3 "topology_description": { 4 "type": "Unknown", 5 "servers": [ 6 { 7 "address": "a:27017", 8 "type": "Unknown", 9 "maxWireVersion": 6 10 } 11 ] 12 }, 13 "read_preference": { 14 "mode": "Nearest", 15 "maxStalenessSeconds": 1 16 }, 17 "suitable_servers": [], 18 "in_latency_window": [] 19}