description: "New primary with greater setVersion and electionId" uri: "mongodb://a/?replicaSet=rs" phases: [ # Primary A is discovered and tells us about B. { responses: [ ["a:27017", { ok: 1, ismaster: true, hosts: ["a:27017", "b:27017"], setName: "rs", setVersion: 1, electionId: {"$oid": "000000000000000000000001"}, minWireVersion: 0, maxWireVersion: 6 }] ], outcome: { servers: { "a:27017": { type: "RSPrimary", setName: "rs", setVersion: 1, electionId: {"$oid": "000000000000000000000001"} }, "b:27017": { type: "Unknown", setName: , electionId: } }, topologyType: "ReplicaSetWithPrimary", logicalSessionTimeoutMinutes: null, setName: "rs", maxSetVersion: 1, maxElectionId: {"$oid": "000000000000000000000001"}, } }, # B is elected. { responses: [ ["b:27017", { ok: 1, ismaster: true, hosts: ["a:27017", "b:27017"], setName: "rs", setVersion: 1, electionId: {"$oid": "000000000000000000000002"}, minWireVersion: 0, maxWireVersion: 6 }] ], outcome: { servers: { "a:27017": { type: "Unknown", setName: , electionId: }, "b:27017": { type: "RSPrimary", setName: "rs", setVersion: 1, electionId: {"$oid": "000000000000000000000002"} } }, topologyType: "ReplicaSetWithPrimary", logicalSessionTimeoutMinutes: null, setName: "rs", maxSetVersion: 1, maxElectionId: {"$oid": "000000000000000000000002"}, } }, # A still claims to be primary but it's ignored. { responses: [ ["a:27017", { ok: 1, ismaster: true, hosts: ["a:27017", "b:27017"], setName: "rs", setVersion: 1, electionId: {"$oid": "000000000000000000000001"}, minWireVersion: 0, maxWireVersion: 6 }] ], outcome: { servers: { "a:27017": { type: "Unknown", setName: , electionId: }, "b:27017": { type: "RSPrimary", setName: "rs", setVersion: 1, electionId: {"$oid": "000000000000000000000002"} } }, topologyType: "ReplicaSetWithPrimary", logicalSessionTimeoutMinutes: null, setName: "rs", maxSetVersion: 1, maxElectionId: {"$oid": "000000000000000000000002"}, } } ]