diff --git a/lib/mongo/cluster/topology/replica_set.rb b/lib/mongo/cluster/topology/replica_set.rb
index ccbb673be9..590e2189c4 100644
--- a/lib/mongo/cluster/topology/replica_set.rb
+++ b/lib/mongo/cluster/topology/replica_set.rb
@@ -68,6 +68,7 @@ def elect_primary(description, servers)
                 end
               end
               update_max_election_id(description)
+              update_max_set_version(description)
             end
           else
             log_warn(
@@ -88,7 +89,8 @@ def elect_primary(description, servers)
         # @since 2.0.0
         def initialize(options, seeds = [])
           @options = options
-          @max_election_id = 0
+          @max_election_id = nil
+          @max_set_version = nil
         end
 
         # A replica set topology is a replica set.
@@ -222,14 +224,29 @@ def standalone_discovered; self; end
         private
 
         def update_max_election_id(description)
-          if description.election_id && description.election_id > @max_election_id
+          if description.election_id &&
+              (@max_election_id.nil? ||
+                  description.election_id > @max_election_id)
             @max_election_id = description.election_id
           end
         end
 
+        def update_max_set_version(description)
+          if description.set_version &&
+              (@max_set_version.nil? ||
+                  description.set_version > @max_set_version)
+            @max_set_version = description.set_version
+          end
+        end
+
         def detect_stale_primary!(description)
-          if description.election_id && description.election_id < @max_election_id
-            description.unknown!
+          if description.election_id && description.set_version
+            if @max_set_version && @max_election_id &&
+                (description.set_version < @max_set_version ||
+                    (description.set_version == @max_set_version &&
+                        description.election_id < @max_election_id))
+              description.unknown!
+            end
           end
         end
 
diff --git a/lib/mongo/server/description.rb b/lib/mongo/server/description.rb
index ddcac09de0..c51b1653ca 100644
--- a/lib/mongo/server/description.rb
+++ b/lib/mongo/server/description.rb
@@ -129,11 +129,16 @@ class Description
       # @since 2.0.0
       TAGS = 'tags'.freeze
 
-      # Constant for reading electionID info from config.
+      # Constant for reading electionId info from config.
       #
       # @since 2.1.0
       ELECTION_ID = 'electionId'.freeze
 
+      # Constant for reading setVersion info from config.
+      #
+      # @since 2.2.2
+      SET_VERSION = 'setVersion'.freeze
+
       # Constant for reading localTime info from config.
       #
       # @since 2.1.0
@@ -142,7 +147,7 @@ class Description
       # Fields to exclude when comparing two descriptions.
       #
       # @since 2.0.6
-      EXCLUDE_FOR_COMPARISON = [ LOCAL_TIME, ELECTION_ID ].freeze
+      EXCLUDE_FOR_COMPARISON = [ LOCAL_TIME, ELECTION_ID, SET_VERSION ].freeze
 
       # @return [ Address ] address The server's address.
       attr_reader :address
@@ -343,6 +348,18 @@ def election_id
         config[ELECTION_ID]
       end
 
+      # Get the setVersion from the config.
+      #
+      # @example Get the setVersion.
+      #   description.set_version
+      #
+      # @return [ Integer ] The set version.
+      #
+      # @since 2.2.2
+      def set_version
+        config[SET_VERSION]
+      end
+
       # Is the server a mongos?
       #
       # @example Is the server a mongos?
diff --git a/spec/support/sdam/rs/equal_electionids.yml b/spec/support/sdam/rs/equal_electionids.yml
index a7f6e1a539..271e4fa0c4 100644
--- a/spec/support/sdam/rs/equal_electionids.yml
+++ b/spec/support/sdam/rs/equal_electionids.yml
@@ -12,6 +12,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }],
             ["b:27017", {
@@ -19,6 +20,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }]
         ],
@@ -29,11 +31,13 @@ phases: [
                 "a:27017": {
                     type: "Unknown",
                     setName: ,
+                    setVersion: ,
                     electionId:
                 },
                 "b:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000001"}
                 }
             },
diff --git a/spec/support/sdam/rs/new_primary_new_electionid.yml b/spec/support/sdam/rs/new_primary_new_electionid.yml
index f38906fc14..e7b0d1d670 100644
--- a/spec/support/sdam/rs/new_primary_new_electionid.yml
+++ b/spec/support/sdam/rs/new_primary_new_electionid.yml
@@ -1,4 +1,4 @@
-description: "New primary with greater electionId"
+description: "New primary with greater setVersion and electionId"
 
 uri: "mongodb://a/?replicaSet=rs"
 
@@ -12,6 +12,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }]
         ],
@@ -21,6 +22,7 @@ phases: [
                 "a:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000001"}
                 },
                 "b:27017": {
@@ -42,6 +44,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000002"}
             }]
         ],
@@ -56,6 +59,7 @@ phases: [
                 "b:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000002"}
                 }
             },
@@ -72,6 +76,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }]
         ],
@@ -85,6 +90,7 @@ phases: [
                 "b:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000002"}
                 }
             },
diff --git a/spec/support/sdam/rs/new_primary_new_setversion.yml b/spec/support/sdam/rs/new_primary_new_setversion.yml
new file mode 100644
index 0000000000..df83bedcee
--- /dev/null
+++ b/spec/support/sdam/rs/new_primary_new_setversion.yml
@@ -0,0 +1,101 @@
+description: "New primary with greater setVersion"
+
+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: {"$oid": "000000000000000000000001"}
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 1,
+                    electionId: {"$oid": "000000000000000000000001"}
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # RS is reconfigured and B is elected.
+    {
+        responses: [
+            ["b:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 2,
+                electionId: {"$oid": "000000000000000000000001"}
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2,
+                    electionId: {"$oid": "000000000000000000000001"}
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # 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: {"$oid": "000000000000000000000001"}
+            }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2,
+                    electionId: {"$oid": "000000000000000000000002"}
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    }
+]
diff --git a/spec/support/sdam/rs/null_election_id.yml b/spec/support/sdam/rs/null_election_id.yml
index 7608c6e4c5..d990d28a0e 100644
--- a/spec/support/sdam/rs/null_election_id.yml
+++ b/spec/support/sdam/rs/null_election_id.yml
@@ -11,6 +11,7 @@ phases: [
                 ok: 1,
                 ismaster: true,
                 hosts: ["a:27017", "b:27017", "c:27017"],
+                setVersion: 1,
                 setName: "rs"
             }]
         ],
@@ -20,6 +21,7 @@ phases: [
                 "a:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId:
                 },
                 "b:27017": {
@@ -46,6 +48,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017", "c:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000002"}
             }]
         ],
@@ -60,6 +63,7 @@ phases: [
                 "b:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000002"}
                 },
                 "c:27017": {
@@ -80,6 +84,7 @@ phases: [
                 ok: 1,
                 ismaster: true,
                 hosts: ["a:27017", "b:27017", "c:27017"],
+                setVersion: 1,
                 setName: "rs"
             }]
         ],
@@ -88,6 +93,7 @@ phases: [
                 "a:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId:
                 },
                 "b:27017": {
@@ -106,7 +112,7 @@ phases: [
         }
     },
 
-    # But we remember A's electionId, so when we finally hear from C
+    # But we remember B's electionId, so when we finally hear from C
     # claiming it is primary, we ignore it due to its outdated electionId
     {
         responses: [
@@ -115,6 +121,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017", "c:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }]
         ],
diff --git a/spec/support/sdam/rs/primary_disconnect_electionid.yml b/spec/support/sdam/rs/primary_disconnect_electionid.yml
index 3d009a7eaa..0c4db3dd4b 100644
--- a/spec/support/sdam/rs/primary_disconnect_electionid.yml
+++ b/spec/support/sdam/rs/primary_disconnect_electionid.yml
@@ -1,4 +1,4 @@
-description: "Disconnected from primary, reject stale primary"
+description: "Disconnected from primary, reject primary with stale electionId"
 
 uri: "mongodb://a/?replicaSet=rs"
 
@@ -12,6 +12,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }],
             ["b:27017", {
@@ -19,6 +20,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000002"}
             }]
         ],
@@ -33,6 +35,7 @@ phases: [
                 "b:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000002"}
                 }
             },
@@ -72,6 +75,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000001"}
             }]
         ],
@@ -101,6 +105,7 @@ phases: [
                 ismaster: true,
                 hosts: ["a:27017", "b:27017"],
                 setName: "rs",
+                setVersion: 1,
                 electionId: {"$oid": "000000000000000000000003"}
             }]
         ],
@@ -109,6 +114,7 @@ phases: [
                 "a:27017": {
                     type: "RSPrimary",
                     setName: "rs",
+                    setVersion: 1,
                     electionId: {"$oid": "000000000000000000000003"}
                 },
                 "b:27017": {
@@ -120,5 +126,35 @@ phases: [
             topologyType: "ReplicaSetWithPrimary",
             setName: "rs",
         }
+    },
+
+    # B comes back as secondary.
+    {
+        responses: [
+            ["b:27017", {
+                ok: 1,
+                ismaster: false,
+                secondary: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 2
+            }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 1,
+                    electionId: {"$oid": "000000000000000000000002"}
+                },
+                "b:27017": {
+                    type: "RSSecondary",
+                    setName: "rs"
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
     }
 ]
diff --git a/spec/support/sdam/rs/primary_disconnect_setversion.yml b/spec/support/sdam/rs/primary_disconnect_setversion.yml
new file mode 100644
index 0000000000..89daf3a951
--- /dev/null
+++ b/spec/support/sdam/rs/primary_disconnect_setversion.yml
@@ -0,0 +1,160 @@
+description: "Disconnected from primary, reject primary with stale setVersion"
+
+uri: "mongodb://a/?replicaSet=rs"
+
+phases: [
+
+    # A is elected, then B after a reconfig.
+    {
+        responses: [
+            ["a:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 1,
+                electionId: {"$oid": "000000000000000000000001"}
+            }],
+            ["b:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 2,
+                electionId: {"$oid": "000000000000000000000001"}
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2,
+                    electionId: {"$oid": "000000000000000000000001"}
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # Disconnected from B.
+    {
+        responses: [
+            ["b:27017", {}]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetNoPrimary",
+            setName: "rs",
+        }
+    },
+
+    # 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: {"$oid": "000000000000000000000001"}
+            }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetNoPrimary",
+            setName: "rs",
+        }
+    },
+
+    # Now A is re-elected.
+    {
+        responses: [
+            ["a:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 2,
+                electionId: {"$oid": "000000000000000000000002"}
+            }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2,
+                    electionId: {"$oid": "000000000000000000000002"}
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # B comes back as secondary.
+    {
+        responses: [
+            ["b:27017", {
+                ok: 1,
+                ismaster: false,
+                secondary: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 2
+            }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2,
+                    electionId: {"$oid": "000000000000000000000002"}
+                },
+                "b:27017": {
+                    type: "RSSecondary",
+                    setName: "rs"
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    }
+]
diff --git a/spec/support/sdam/rs/set_version_without_electionid.yml b/spec/support/sdam/rs/set_version_without_electionid.yml
new file mode 100644
index 0000000000..2b11050c22
--- /dev/null
+++ b/spec/support/sdam/rs/set_version_without_electionid.yml
@@ -0,0 +1,69 @@
+description: "setVersion is ignored if there is no 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: 2
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2 ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # B is elected, its setVersion is older but we believe it anyway, because
+    # setVersion is only used in conjunction with electionId.
+    {
+        responses: [
+            ["b:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 1
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 1,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    }
+]
diff --git a/spec/support/sdam/rs/setversion_without_electionid.yml b/spec/support/sdam/rs/setversion_without_electionid.yml
new file mode 100644
index 0000000000..2b11050c22
--- /dev/null
+++ b/spec/support/sdam/rs/setversion_without_electionid.yml
@@ -0,0 +1,69 @@
+description: "setVersion is ignored if there is no 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: 2
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2 ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # B is elected, its setVersion is older but we believe it anyway, because
+    # setVersion is only used in conjunction with electionId.
+    {
+        responses: [
+            ["b:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 1
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 1,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    }
+]
diff --git a/spec/support/sdam/rs/use_setversion_without_electionid.yml b/spec/support/sdam/rs/use_setversion_without_electionid.yml
new file mode 100644
index 0000000000..505ed0b4dc
--- /dev/null
+++ b/spec/support/sdam/rs/use_setversion_without_electionid.yml
@@ -0,0 +1,99 @@
+description: "Record max setVersion, even from primary without electionId"
+
+uri: "mongodb://a/?replicaSet=rs"
+
+phases: [
+
+    # Primary A has setVersion and electionId, tells us about B.
+    {
+        responses: [
+            ["a:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 1,
+                electionId: {"$oid": "000000000000000000000001"}
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 1,
+                    electionId: {"$oid": "000000000000000000000001"}
+                },
+                "b:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # Reconfig the set and elect B, it has a new setVersion but no electionId.
+    {
+        responses: [
+            ["b:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 2
+            }]
+        ],
+
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    },
+
+    # Delayed response from A, reporting its reelection. Its setVersion shows
+    # the election preceded B's so we ignore it.
+    {
+        responses: [
+            ["a:27017", {
+                ok: 1,
+                ismaster: true,
+                hosts: ["a:27017", "b:27017"],
+                setName: "rs",
+                setVersion: 1,
+                electionId: {"$oid": "000000000000000000000002"}
+            }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "Unknown",
+                    setName: ,
+                    electionId:
+                },
+                "b:27017": {
+                    type: "RSPrimary",
+                    setName: "rs",
+                    setVersion: 2
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+        }
+    }
+]