{ "heartbeatFrequencyMS": 25000, "topology_description": { "type": "ReplicaSetNoPrimary", "servers": [ { "address": "a:27017", "type": "RSSecondary", "avg_rtt_ms": 5, "lastUpdateTime": 0, "lastWrite": { "lastWriteDate": { "$numberLong": "125002" } }, "maxWireVersion": 6 }, { "address": "b:27017", "type": "RSSecondary", "avg_rtt_ms": 50, "lastUpdateTime": 0, "lastWrite": { "lastWriteDate": { "$numberLong": "2" } }, "maxWireVersion": 6 }, { "address": "c:27017", "avg_rtt_ms": 5, "lastUpdateTime": 0, "type": "RSSecondary", "lastWrite": { "lastWriteDate": { "$numberLong": "1" } }, "maxWireVersion": 6 } ] }, "read_preference": { "mode": "Nearest", "maxStalenessSeconds": 150 }, "suitable_servers": [ { "address": "a:27017", "type": "RSSecondary", "avg_rtt_ms": 5, "lastUpdateTime": 0, "lastWrite": { "lastWriteDate": { "$numberLong": "125002" } }, "maxWireVersion": 6 }, { "address": "b:27017", "type": "RSSecondary", "avg_rtt_ms": 50, "lastUpdateTime": 0, "lastWrite": { "lastWriteDate": { "$numberLong": "2" } }, "maxWireVersion": 6 } ], "in_latency_window": [ { "address": "a:27017", "type": "RSSecondary", "avg_rtt_ms": 5, "lastUpdateTime": 0, "lastWrite": { "lastWriteDate": { "$numberLong": "125002" } }, "maxWireVersion": 6 } ] }