SERVER-28680: Fix naming of lastCommittedOp field in replSetRequestVotes

8 files changed, 145 insertions, 57 deletions

diff --git a/src/mongo/db/repl/repl_set_request_votes_args.cpp b/src/mongo/db/repl/repl_set_request_votes_args.cpp
index e72af47af64..d5a3b5b22a3 100644
--- a/src/mongo/db/repl/repl_set_request_votes_args.cpp
+++ b/src/mongo/db/repl/repl_set_request_votes_args.cpp
@@ -44,9 +44,9 @@ const std::string kCommandName = "replSetRequestVotes";
 const std::string kConfigVersionFieldName = "configVersion";
 const std::string kConfigTermFieldName = "configTerm";
 const std::string kDryRunFieldName = "dryRun";
-// The underlying field name is inaccurate, but changing it requires a fair amount of cross
-// compatibility work for no real benefit.
+// TODO: Remove references to the "lastCommittedOp" field name (SERVER-46090).
 const std::string kLastDurableOpTimeFieldName = "lastCommittedOp";
+const std::string kLastAppliedOpTimeFieldName = "lastAppliedOpTime";
 const std::string kOkFieldName = "ok";
 const std::string kReasonFieldName = "reason";
 const std::string kSetNameFieldName = "setName";
@@ -54,7 +54,8 @@ const std::string kTermFieldName = "term";
 const std::string kVoteGrantedFieldName = "voteGranted";
 const std::string kOperationTime = "operationTime";
 
-const std::string kLegalArgsFieldNames[] = {
+// TODO: `kLegalArgsFieldNamesFCV42` should be removed after upgrading to 4.6 (SERVER-46090).
+const std::string kLegalArgsFieldNamesFCV42[] = {
     kCandidateIndexFieldName,
     kCommandName,
     kConfigVersionFieldName,
@@ -66,14 +67,42 @@ const std::string kLegalArgsFieldNames[] = {
     kOperationTime,
 };
 
+const std::string kLegalArgsFieldNames[] = {
+    kCandidateIndexFieldName,
+    kCommandName,
+    kConfigVersionFieldName,
+    kConfigTermFieldName,
+    kDryRunFieldName,
+    kLastAppliedOpTimeFieldName,
+    kSetNameFieldName,
+    kTermFieldName,
+    kOperationTime,
+};
+
 }  // namespace
 
 
 Status ReplSetRequestVotesArgs::initialize(const BSONObj& argsObj) {
     Status status =
         bsonCheckOnlyHasFieldsForCommand("ReplSetRequestVotes", argsObj, kLegalArgsFieldNames);
-    if (!status.isOK())
-        return status;
+    // TODO: Remove this logic once we branch to 4.6 and can always assume
+    // _usingLastAppliedOptimeFieldName to be true (SERVER-46090).
+    // Since nodes in the replica set may have different values for FCV, we check that the legal
+    // field names of either FCV 4.2 or 4.4 are present in the args obj.
+    if (!status.isOK()) {
+        status = bsonCheckOnlyHasFieldsForCommand(
+            "ReplSetRequestVotes", argsObj, kLegalArgsFieldNamesFCV42);
+        if (!status.isOK())
+            return status;
+
+        // If we successfully parsed with the FCV 4.2 field names, use 'lastCommittedOp' as the
+        // correct field name.
+        _usingLastAppliedOpTimeFieldName = false;
+    } else {
+        // If we successfully parsed with the FCV 4.4 field names, use 'lastAppliedOpTime' as the
+        // correct field name.
+        _usingLastAppliedOpTimeFieldName = true;
+    }
 
     status = bsonExtractIntegerField(argsObj, kTermFieldName, &_term);
     if (!status.isOK())
@@ -102,9 +131,16 @@ Status ReplSetRequestVotesArgs::initialize(const BSONObj& argsObj) {
     if (!status.isOK())
         return status;
 
-    status = bsonExtractOpTimeField(argsObj, kLastDurableOpTimeFieldName, &_lastDurableOpTime);
-    if (!status.isOK())
+    // If we successfully parsed with the FCV 4.4 field names, use 'lastAppliedOpTime' to extract
+    // the data. Else, use 'lastCommittedOp' as the field name.
+    if (_usingLastAppliedOpTimeFieldName) {
+        status = bsonExtractOpTimeField(argsObj, kLastAppliedOpTimeFieldName, &_lastAppliedOpTime);
+    } else {
+        status = bsonExtractOpTimeField(argsObj, kLastDurableOpTimeFieldName, &_lastAppliedOpTime);
+    }
+    if (!status.isOK()) {
         return status;
+    }
 
     return Status::OK();
 }
@@ -133,8 +169,8 @@ ConfigVersionAndTerm ReplSetRequestVotesArgs::getConfigVersionAndTerm() const {
     return ConfigVersionAndTerm(_cfgVer, _cfgTerm);
 }
 
-OpTime ReplSetRequestVotesArgs::getLastDurableOpTime() const {
-    return _lastDurableOpTime;
+OpTime ReplSetRequestVotesArgs::getLastAppliedOpTime() const {
+    return _lastAppliedOpTime;
 }
 
 bool ReplSetRequestVotesArgs::isADryRun() const {
@@ -149,7 +185,11 @@ void ReplSetRequestVotesArgs::addToBSON(BSONObjBuilder* builder) const {
     builder->appendIntOrLL(kCandidateIndexFieldName, _candidateIndex);
     builder->appendIntOrLL(kConfigVersionFieldName, _cfgVer);
     builder->appendIntOrLL(kConfigTermFieldName, _cfgTerm);
-    _lastDurableOpTime.append(builder, kLastDurableOpTimeFieldName);
+    if (_usingLastAppliedOpTimeFieldName) {
+        _lastAppliedOpTime.append(builder, kLastAppliedOpTimeFieldName);
+    } else {
+        _lastAppliedOpTime.append(builder, kLastDurableOpTimeFieldName);
+    }
 }
 
 std::string ReplSetRequestVotesArgs::toString() const {
diff --git a/src/mongo/db/repl/repl_set_request_votes_args.h b/src/mongo/db/repl/repl_set_request_votes_args.h
index c86429e79ed..3e91de7ad56 100644
--- a/src/mongo/db/repl/repl_set_request_votes_args.h
+++ b/src/mongo/db/repl/repl_set_request_votes_args.h
@@ -50,7 +50,7 @@ public:
     long long getConfigVersion() const;
     long long getConfigTerm() const;
     ConfigVersionAndTerm getConfigVersionAndTerm() const;
-    OpTime getLastDurableOpTime() const;
+    OpTime getLastAppliedOpTime() const;
     bool isADryRun() const;
 
     void addToBSON(BSONObjBuilder* builder) const;
@@ -64,8 +64,14 @@ private:
     long long _cfgVer = -1;  // replSet config version known to the command issuer.
     // replSet config term known to the command issuer.
     long long _cfgTerm = OpTime::kUninitializedTerm;
-    OpTime _lastDurableOpTime;  // The last known durable op of the command issuer.
+    OpTime _lastAppliedOpTime;  // The OpTime of the last known applied op of the command issuer.
     bool _dryRun = false;       // Indicates this is a pre-election check when true.
+
+    // TODO: Remove this field once references to 'lastCommittedOp' can be removed in 4.6 and we can
+    // assume _usingLastAppliedOpTimeFieldName to always be true (SERVER-46090).
+    // When true, indicates that we should use the 'lastAppliedOpTime' field for logging the last
+    // applied OpTime. Else, use 'lastCommittedOp'.
+    bool _usingLastAppliedOpTimeFieldName = true;
 };
 
 class ReplSetRequestVotesResponse {
diff --git a/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp b/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp
index 61910c41c1e..5488b9a68f7 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp
@@ -136,9 +136,9 @@ void ReplicationCoordinatorImpl::_startElectSelfV1_inlock(StartElectionReasonEnu
 
 
     invariant(_rsConfig.getMemberAt(_selfIndex).isElectable());
-    const auto lastOpTime = _getMyLastAppliedOpTime_inlock();
+    const auto lastAppliedOpTime = _getMyLastAppliedOpTime_inlock();
 
-    if (lastOpTime == OpTime()) {
+    if (lastAppliedOpTime == OpTime()) {
         LOGV2(21436,
               "not trying to elect self, "
               "do not yet have a complete set of data from any point in time");
@@ -173,7 +173,7 @@ void ReplicationCoordinatorImpl::_startElectSelfV1_inlock(StartElectionReasonEnu
                               _selfIndex,
                               term,
                               true,  // dry run
-                              lastOpTime,
+                              lastAppliedOpTime,
                               primaryIndex);
     if (nextPhaseEvh.getStatus() == ErrorCodes::ShutdownInProgress) {
         return;
@@ -328,11 +328,11 @@ void ReplicationCoordinatorImpl::_writeLastVoteForMyElection(
 
 void ReplicationCoordinatorImpl::_startVoteRequester_inlock(long long newTerm,
                                                             StartElectionReasonEnum reason) {
-    const auto lastOpTime = _getMyLastAppliedOpTime_inlock();
+    const auto lastAppliedOpTime = _getMyLastAppliedOpTime_inlock();
 
     _voteRequester.reset(new VoteRequester);
     StatusWith<executor::TaskExecutor::EventHandle> nextPhaseEvh = _voteRequester->start(
-        _replExecutor.get(), _rsConfig, _selfIndex, newTerm, false, lastOpTime, -1);
+        _replExecutor.get(), _rsConfig, _selfIndex, newTerm, false, lastAppliedOpTime, -1);
     if (nextPhaseEvh.getStatus() == ErrorCodes::ShutdownInProgress) {
         return;
     }
diff --git a/src/mongo/db/repl/replication_coordinator_impl_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
index b7fba917f79..35c002d78b4 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
@@ -6895,7 +6895,7 @@ TEST_F(ReplCoordTest, NodeStoresElectionVotes) {
                                                          << "mySet"
                                                          << "term" << 7LL << "candidateIndex" << 2LL
                                                          << "configVersion" << 2LL << "dryRun"
-                                                         << false << "lastCommittedOp"
+                                                         << false << "lastAppliedOpTime"
                                                          << time.asOpTime().toBSON())));
     ReplSetRequestVotesResponse response;
 
@@ -6938,7 +6938,7 @@ TEST_F(ReplCoordTest, NodeDoesNotStoreDryRunVotes) {
                                                          << "mySet"
                                                          << "term" << 7LL << "candidateIndex" << 2LL
                                                          << "configVersion" << 2LL << "dryRun"
-                                                         << true << "lastCommittedOp"
+                                                         << true << "lastAppliedOpTime"
                                                          << time.asOpTime().toBSON())));
     ReplSetRequestVotesResponse response;
 
@@ -6985,7 +6985,7 @@ TEST_F(ReplCoordTest, NodeFailsVoteRequestIfItFailsToStoreLastVote) {
                                    << "mySet"
                                    << "term" << initTerm + 1  // term of new candidate.
                                    << "candidateIndex" << 1LL << "configVersion" << 2LL << "dryRun"
-                                   << false << "lastCommittedOp" << time.asOpTime().toBSON())));
+                                   << false << "lastAppliedOpTime" << time.asOpTime().toBSON())));
     ReplSetRequestVotesResponse response;
 
     // Simulate a failure to write the 'last vote' document. The specific error code isn't
@@ -7036,7 +7036,7 @@ TEST_F(ReplCoordTest, NodeNodesNotGrantVoteIfInTerminalShutdown) {
                                    << "mySet"
                                    << "term" << initTerm + 1  // term of new candidate.
                                    << "candidateIndex" << 1LL << "configVersion" << 2LL << "dryRun"
-                                   << false << "lastCommittedOp" << time.asOpTime().toBSON())));
+                                   << false << "lastAppliedOpTime" << time.asOpTime().toBSON())));
     ReplSetRequestVotesResponse response;
 
     getReplCoord()->enterTerminalShutdown();
diff --git a/src/mongo/db/repl/topology_coordinator.cpp b/src/mongo/db/repl/topology_coordinator.cpp
index 2b329b0f0d6..7160264baac 100644
--- a/src/mongo/db/repl/topology_coordinator.cpp
+++ b/src/mongo/db/repl/topology_coordinator.cpp
@@ -2931,12 +2931,12 @@ void TopologyCoordinator::processReplSetRequestVotes(const ReplSetRequestVotesAr
         response->setReason(str::stream()
                             << "candidate's set name ({}) differs from mine ({})"_format(
                                    args.getSetName(), _rsConfig.getReplSetName()));
-    } else if (args.getLastDurableOpTime() < getMyLastAppliedOpTime()) {
+    } else if (args.getLastAppliedOpTime() < getMyLastAppliedOpTime()) {
         response->setVoteGranted(false);
         response->setReason(str::stream()
                             << "candidate's data is staler than mine. candidate's last applied "
                                "OpTime: {}, my last applied OpTime: {}"_format(
-                                   args.getLastDurableOpTime().toString(),
+                                   args.getLastAppliedOpTime().toString(),
                                    getMyLastAppliedOpTime().toString()));
     } else if (!args.isADryRun() && _lastVote.getTerm() == args.getTerm()) {
         response->setVoteGranted(false);
diff --git a/src/mongo/db/repl/topology_coordinator_v1_test.cpp b/src/mongo/db/repl/topology_coordinator_v1_test.cpp
index cf41b85b78d..cd3cd98643f 100644
--- a/src/mongo/db/repl/topology_coordinator_v1_test.cpp
+++ b/src/mongo/db/repl/topology_coordinator_v1_test.cpp
@@ -2563,7 +2563,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVotesToTwoDifferentNodesInTheSameTerm) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2578,7 +2578,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVotesToTwoDifferentNodesInTheSameTerm) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 1LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response2;
@@ -2642,7 +2642,7 @@ TEST_F(TopoCoordTest, DryRunVoteRequestShouldNotPreventSubsequentDryRunsForThatT
                                                << "rs0"
                                                << "dryRun" << true << "term" << 1LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2658,7 +2658,7 @@ TEST_F(TopoCoordTest, DryRunVoteRequestShouldNotPreventSubsequentDryRunsForThatT
                                                << "rs0"
                                                << "dryRun" << true << "term" << 1LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response2;
@@ -2674,7 +2674,7 @@ TEST_F(TopoCoordTest, DryRunVoteRequestShouldNotPreventSubsequentDryRunsForThatT
                                                << "rs0"
                                                << "dryRun" << false << "term" << 1LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response3;
@@ -2690,7 +2690,7 @@ TEST_F(TopoCoordTest, DryRunVoteRequestShouldNotPreventSubsequentDryRunsForThatT
                                                << "rs0"
                                                << "dryRun" << false << "term" << 1LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response4;
@@ -2720,7 +2720,7 @@ TEST_F(TopoCoordTest, VoteRequestShouldNotPreventDryRunsForThatTerm) {
                                                << "rs0"
                                                << "dryRun" << false << "term" << 1LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2736,7 +2736,7 @@ TEST_F(TopoCoordTest, VoteRequestShouldNotPreventDryRunsForThatTerm) {
                                                << "rs0"
                                                << "dryRun" << false << "term" << 1LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response2;
@@ -2766,7 +2766,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVoteWhenReplSetNameDoesNotMatch) {
                                                << "wrongName"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2795,7 +2795,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVoteWhenConfigVersionIsLower) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 1LL
                                                << "configVersion" << 0LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2827,7 +2827,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVoteWhenConfigTermIsLower) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 1LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2863,7 +2863,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVoteWhenTermIsStale) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 1LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2894,7 +2894,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantVoteWhenOpTimeIsStale) {
                                                << "rs0"
                                                << "term" << 3LL << "candidateIndex" << 1LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2931,7 +2931,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantDryRunVoteWhenReplSetNameDoesNotMatch) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse responseForRealVote;
@@ -2947,7 +2947,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantDryRunVoteWhenReplSetNameDoesNotMatch) {
                                                << "wrongName"
                                                << "dryRun" << true << "term" << 2LL
                                                << "candidateIndex" << 0LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -2980,7 +2980,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantDryRunVoteWhenConfigVersionIsLower) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse responseForRealVote;
@@ -2996,7 +2996,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantDryRunVoteWhenConfigVersionIsLower) {
                                                << "rs0"
                                                << "dryRun" << true << "term" << 2LL
                                                << "candidateIndex" << 1LL << "configVersion" << 0LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -3032,7 +3032,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantDryRunVoteWhenTermIsStale) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse responseForRealVote;
@@ -3047,7 +3047,7 @@ TEST_F(TopoCoordTest, NodeDoesNotGrantDryRunVoteWhenTermIsStale) {
                                                << "rs0"
                                                << "dryRun" << true << "term" << 0LL
                                                << "candidateIndex" << 1LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -3081,7 +3081,7 @@ TEST_F(TopoCoordTest, NodeGrantsVoteWhenTermIsHigherButConfigVersionIsLower) {
                                                << "rs0"
                                                << "term" << 2LL << "candidateIndex" << 1LL
                                                << "configVersion" << 1LL << "configTerm" << 2LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -3114,7 +3114,7 @@ TEST_F(TopoCoordTest, GrantDryRunVoteEvenWhenTermHasBeenSeen) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse responseForRealVote;
@@ -3130,7 +3130,7 @@ TEST_F(TopoCoordTest, GrantDryRunVoteEvenWhenTermHasBeenSeen) {
                                                << "rs0"
                                                << "dryRun" << true << "term" << 1LL
                                                << "candidateIndex" << 1LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -3163,7 +3163,7 @@ TEST_F(TopoCoordTest, DoNotGrantDryRunVoteWhenOpTimeIsStale) {
                                                << "rs0"
                                                << "term" << 1LL << "candidateIndex" << 0LL
                                                << "configVersion" << 1LL << "configTerm" << 1LL
-                                               << "lastCommittedOp"
+                                               << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse responseForRealVote;
@@ -3179,7 +3179,7 @@ TEST_F(TopoCoordTest, DoNotGrantDryRunVoteWhenOpTimeIsStale) {
                                                << "rs0"
                                                << "dryRun" << true << "term" << 3LL
                                                << "candidateIndex" << 1LL << "configVersion" << 1LL
-                                               << "configTerm" << 1LL << "lastCommittedOp"
+                                               << "configTerm" << 1LL << "lastAppliedOpTime"
                                                << BSON("ts" << Timestamp(10, 0) << "term" << 0LL)))
         .transitional_ignore();
     ReplSetRequestVotesResponse response;
@@ -3195,6 +3195,42 @@ TEST_F(TopoCoordTest, DoNotGrantDryRunVoteWhenOpTimeIsStale) {
     ASSERT_FALSE(response.getVoteGranted());
 }
 
+// TODO: Remove this test in 4.6 when we can remove references to "lastCommittedOp" (SERVER-46090).
+TEST_F(TopoCoordTest, ParseLastAppliedOpTimeWithCorrectFieldName) {
+    const OpTime lastOpTimeApplied = OpTime(Timestamp(4, 0), 0);
+
+    const auto reqVotesObjWithLastAppliedOpTimeField =
+        BSON("replSetRequestVotes" << 1 << "setName"
+                                   << "rs0"
+                                   << "dryRun" << true << "term" << 1LL << "candidateIndex" << 1LL
+                                   << "configVersion" << 1LL << "configTerm" << 1LL
+                                   << "lastAppliedOpTime" << lastOpTimeApplied);
+    ReplSetRequestVotesArgs reqVotesArgsWithLastAppliedOpTimeField;
+    ASSERT_OK(
+        reqVotesArgsWithLastAppliedOpTimeField.initialize(reqVotesObjWithLastAppliedOpTimeField));
+
+    // Verify we successfully parse the args with 'lastAppliedOpTime' as the field name.
+    ASSERT_EQUALS(lastOpTimeApplied, reqVotesArgsWithLastAppliedOpTimeField.getLastAppliedOpTime());
+    // Verify that the request serializes correctly.
+    ASSERT_EQUALS(reqVotesObjWithLastAppliedOpTimeField.toString(),
+                  reqVotesObjWithLastAppliedOpTimeField.toString());
+
+    const auto reqVotesObjWithLastCommittedOpField =
+        BSON("replSetRequestVotes" << 1 << "setName"
+                                   << "rs1"
+                                   << "dryRun" << true << "term" << 1LL << "candidateIndex" << 1LL
+                                   << "configVersion" << 1LL << "configTerm" << 1LL
+                                   << "lastCommittedOp" << lastOpTimeApplied);
+    ReplSetRequestVotesArgs reqVotesArgsWithLastCommittedOpField;
+    ASSERT_OK(reqVotesArgsWithLastCommittedOpField.initialize(reqVotesObjWithLastCommittedOpField));
+
+    // Verify we successfully parse the args with 'lastCommittedOp' as the field name.
+    ASSERT_EQUALS(lastOpTimeApplied, reqVotesArgsWithLastCommittedOpField.getLastAppliedOpTime());
+    // Verify that the request serializes correctly.
+    ASSERT_EQUALS(reqVotesObjWithLastCommittedOpField.toString(),
+                  reqVotesArgsWithLastCommittedOpField.toString());
+}
+
 TEST_F(TopoCoordTest, NodeTransitionsToRemovedIfCSRSButHaveNoReadCommittedSupport) {
     ON_BLOCK_EXIT([]() { serverGlobalParams.clusterRole = ClusterRole::None; });
     serverGlobalParams.clusterRole = ClusterRole::ConfigServer;
diff --git a/src/mongo/db/repl/vote_requester.cpp b/src/mongo/db/repl/vote_requester.cpp
index 64f0d5c172b..27b79ca43bb 100644
--- a/src/mongo/db/repl/vote_requester.cpp
+++ b/src/mongo/db/repl/vote_requester.cpp
@@ -59,13 +59,13 @@ VoteRequester::Algorithm::Algorithm(const ReplSetConfig& rsConfig,
                                     long long candidateIndex,
                                     long long term,
                                     bool dryRun,
-                                    OpTime lastDurableOpTime,
+                                    OpTime lastAppliedOpTime,
                                     int primaryIndex)
     : _rsConfig(rsConfig),
       _candidateIndex(candidateIndex),
       _term(term),
       _dryRun(dryRun),
-      _lastDurableOpTime(lastDurableOpTime) {
+      _lastAppliedOpTime(lastAppliedOpTime) {
     // populate targets with all voting members that aren't this node
     long long index = 0;
     for (auto member = _rsConfig.membersBegin(); member != _rsConfig.membersEnd(); member++) {
@@ -89,15 +89,21 @@ std::vector<RemoteCommandRequest> VoteRequester::Algorithm::getRequests() const
     requestVotesCmdBuilder.append("term", _term);
     requestVotesCmdBuilder.append("candidateIndex", _candidateIndex);
     requestVotesCmdBuilder.append("configVersion", _rsConfig.getConfigVersion());
-    // Only append the config term field to the VoteRequester if we are in FCV 4.4
+
+    // TODO: Remove this check when we upgrade to 4.6 and can remove references to "lastCommittedOp"
+    // (SERVER-46090).
+    // Only append the config term field to the VoteRequester and use "lastAppliedOpTime" as the
+    // field name for _lastAppliedOpTime if we are in FCV 4.4.
     if (serverGlobalParams.featureCompatibility.isVersionInitialized() &&
         serverGlobalParams.featureCompatibility.getVersion() ==
             ServerGlobalParams::FeatureCompatibility::Version::kFullyUpgradedTo44) {
         requestVotesCmdBuilder.append("configTerm", _rsConfig.getConfigTerm());
+        _lastAppliedOpTime.append(&requestVotesCmdBuilder, "lastAppliedOpTime");
+    } else {
+        // If we are not in FCV 4.4, use "lastCommittedOp" as the field name instead.
+        _lastAppliedOpTime.append(&requestVotesCmdBuilder, "lastCommittedOp");
     }
 
-    _lastDurableOpTime.append(&requestVotesCmdBuilder, "lastCommittedOp");
-
     const BSONObj requestVotesCmd = requestVotesCmdBuilder.obj();
 
     std::vector<RemoteCommandRequest> requests;
@@ -219,10 +225,10 @@ StatusWith<executor::TaskExecutor::EventHandle> VoteRequester::start(
     long long candidateIndex,
     long long term,
     bool dryRun,
-    OpTime lastDurableOpTime,
+    OpTime lastAppliedOpTime,
     int primaryIndex) {
     _algorithm = std::make_shared<Algorithm>(
-        rsConfig, candidateIndex, term, dryRun, lastDurableOpTime, primaryIndex);
+        rsConfig, candidateIndex, term, dryRun, lastAppliedOpTime, primaryIndex);
     _runner = std::make_unique<ScatterGatherRunner>(_algorithm, executor, "vote request");
     return _runner->start();
 }
diff --git a/src/mongo/db/repl/vote_requester.h b/src/mongo/db/repl/vote_requester.h
index 6eed65bc1e3..14a13f1f465 100644
--- a/src/mongo/db/repl/vote_requester.h
+++ b/src/mongo/db/repl/vote_requester.h
@@ -59,7 +59,7 @@ public:
                   long long candidateIndex,
                   long long term,
                   bool dryRun,
-                  OpTime lastDurableOpTime,
+                  OpTime lastAppliedOpTime,
                   int primaryIndex);
         virtual ~Algorithm();
         virtual std::vector<executor::RemoteCommandRequest> getRequests() const;
@@ -86,7 +86,7 @@ public:
         const long long _candidateIndex;
         const long long _term;
         bool _dryRun = false;  // this bool indicates this is a mock election when true
-        const OpTime _lastDurableOpTime;
+        const OpTime _lastAppliedOpTime;
         std::vector<HostAndPort> _targets;
         stdx::unordered_set<HostAndPort> _responders;
         bool _staleTerm = false;
@@ -113,7 +113,7 @@ public:
                                                           long long candidateIndex,
                                                           long long term,
                                                           bool dryRun,
-                                                          OpTime lastDurableOpTime,
+                                                          OpTime lastAppliedOpTime,
                                                           int primaryIndex);
 
     /**