1# Latest secondary's lastWriteDate is used normally with read preference tags. 2--- 3heartbeatFrequencyMS: 25000 # 25 seconds. 4topology_description: 5 type: ReplicaSetNoPrimary 6 servers: 7 - &1 8 address: a:27017 9 type: RSSecondary 10 avg_rtt_ms: 5 11 lastUpdateTime: 0 12 maxWireVersion: 5 13 lastWrite: {lastWriteDate: {$numberLong: "125002"}} 14 tags: 15 data_center: tokyo # No match, but its lastWriteDate is used in estimate. 16 - &2 17 address: b:27017 18 type: RSSecondary 19 avg_rtt_ms: 5 20 lastUpdateTime: 0 21 maxWireVersion: 5 22 lastWrite: {lastWriteDate: {$numberLong: "2"}} # 125 sec stale + 25 sec heartbeat <= 150 sec maxStaleness. 23 tags: 24 data_center: nyc 25 - &3 26 address: c:27017 27 type: RSSecondary 28 avg_rtt_ms: 5 29 lastUpdateTime: 0 30 maxWireVersion: 5 31 lastWrite: {lastWriteDate: {$numberLong: "1"}} # Too stale. 32 tags: 33 data_center: nyc 34 - &4 35 address: d:27017 36 type: RSSecondary 37 avg_rtt_ms: 5 38 lastUpdateTime: 0 39 maxWireVersion: 5 40 lastWrite: {lastWriteDate: {$numberLong: "2"}} 41 tags: 42 data_center: tokyo # No match. 43read_preference: 44 mode: Secondary 45 maxStalenessSeconds: 150 46 tag_sets: 47 - data_center: nyc 48suitable_servers: 49- *2 50in_latency_window: 51- *2 52