Revert "SERVER-18498 New replica set configurations have protocolVersion=1 by default"

This reverts commit 2c1facf471cce8254e314755c3c7d2fbc753e5f4.

9 files changed, 95 insertions, 138 deletions

diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 031558554c4..d6de5b44011 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -1891,7 +1891,7 @@ Status ReplicationCoordinatorImpl::processReplSetReconfig(OperationContext* txn,
     if (args.force) {
         newConfigObj = incrementConfigVersionByRandom(newConfigObj);
     }
-    Status status = newConfig.initialize(newConfigObj, oldConfig.getProtocolVersion() == 1);
+    Status status = newConfig.initialize(newConfigObj);
     if (!status.isOK()) {
         error() << "replSetReconfig got " << status << " while parsing " << newConfigObj;
         return Status(ErrorCodes::InvalidReplicaSetConfig, status.reason());
@@ -2003,10 +2003,11 @@ Status ReplicationCoordinatorImpl::processReplSetInitiate(OperationContext* txn,
     }
 
     ReplicaSetConfig newConfig;
-    Status status = newConfig.initialize(configObj, true);
+    Status status = newConfig.initialize(configObj);
     if (!status.isOK()) {
         error() << "replSet initiate got " << status << " while parsing " << configObj;
         return Status(ErrorCodes::InvalidReplicaSetConfig, status.reason());
+        ;
     }
     if (replEnabled && newConfig.getReplSetName() != _settings.ourSetName()) {
         str::stream errmsg;
diff --git a/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp
index e75ad1a675c..1eb90c747ac 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp
@@ -54,15 +54,10 @@ using executor::RemoteCommandResponse;
 
 class ReplCoordElectTest : public ReplCoordTest {
 protected:
-    void assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost);
     void simulateEnoughHeartbeatsForElectability();
     void simulateFreshEnoughForElectability();
 };
 
-void ReplCoordElectTest::assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost) {
-    ReplCoordTest::assertStartSuccess(addProtocolVersion(configDoc, 0), selfHost);
-}
-
 void ReplCoordElectTest::simulateEnoughHeartbeatsForElectability() {
     ReplicationCoordinatorImpl* replCoord = getReplCoord();
     ReplicaSetConfig rsConfig = replCoord->getReplicaSetConfig_forTest();
diff --git a/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp
index 0c630f772a5..fa9843b15ad 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp
@@ -53,17 +53,12 @@ using executor::RemoteCommandResponse;
 
 class ReplCoordHBTest : public ReplCoordTest {
 protected:
-    void assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost);
     void assertMemberState(MemberState expected, std::string msg = "");
     ReplSetHeartbeatResponse receiveHeartbeatFrom(const ReplicaSetConfig& rsConfig,
                                                   int sourceId,
                                                   const HostAndPort& source);
 };
 
-void ReplCoordHBTest::assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost) {
-    ReplCoordTest::assertStartSuccess(addProtocolVersion(configDoc, 0), selfHost);
-}
-
 void ReplCoordHBTest::assertMemberState(const MemberState expected, std::string msg) {
     const MemberState actual = getReplCoord()->getMemberState();
     ASSERT(expected == actual) << "Expected coordinator to report state " << expected.toString()
@@ -88,15 +83,15 @@ ReplSetHeartbeatResponse ReplCoordHBTest::receiveHeartbeatFrom(const ReplicaSetC
 
 TEST_F(ReplCoordHBTest, JoinExistingReplSet) {
     logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
-    ReplicaSetConfig rsConfig = assertMakeRSConfigV0(BSON("_id"
-                                                          << "mySet"
-                                                          << "version" << 3 << "members"
-                                                          << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                                                   << "h1:1")
-                                                                        << BSON("_id" << 2 << "host"
-                                                                                      << "h2:1")
-                                                                        << BSON("_id" << 3 << "host"
-                                                                                      << "h3:1"))));
+    ReplicaSetConfig rsConfig =
+        assertMakeRSConfig(BSON("_id"
+                                << "mySet"
+                                << "version" << 3 << "members"
+                                << BSON_ARRAY(BSON("_id" << 1 << "host"
+                                                         << "h1:1")
+                                              << BSON("_id" << 2 << "host"
+                                                            << "h2:1") << BSON("_id" << 3 << "host"
+                                                                                     << "h3:1"))));
     init("mySet");
     addSelf(HostAndPort("h2", 1));
     const Date_t startDate = getNet()->now();
@@ -151,15 +146,15 @@ TEST_F(ReplCoordHBTest, DoNotJoinReplSetIfNotAMember) {
     // Tests that a node in RS_STARTUP will not transition to RS_REMOVED if it receives a
     // configuration that does not contain it.
     logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
-    ReplicaSetConfig rsConfig = assertMakeRSConfigV0(BSON("_id"
-                                                          << "mySet"
-                                                          << "version" << 3 << "members"
-                                                          << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                                                   << "h1:1")
-                                                                        << BSON("_id" << 2 << "host"
-                                                                                      << "h2:1")
-                                                                        << BSON("_id" << 3 << "host"
-                                                                                      << "h3:1"))));
+    ReplicaSetConfig rsConfig =
+        assertMakeRSConfig(BSON("_id"
+                                << "mySet"
+                                << "version" << 3 << "members"
+                                << BSON_ARRAY(BSON("_id" << 1 << "host"
+                                                         << "h1:1")
+                                              << BSON("_id" << 2 << "host"
+                                                            << "h2:1") << BSON("_id" << 3 << "host"
+                                                                                     << "h3:1"))));
     init("mySet");
     addSelf(HostAndPort("h4", 1));
     const Date_t startDate = getNet()->now();
diff --git a/src/mongo/db/repl/replication_coordinator_impl_heartbeat_v1_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_heartbeat_v1_test.cpp
index 9fc73d5ec61..f7a70005a7f 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_heartbeat_v1_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_heartbeat_v1_test.cpp
@@ -94,7 +94,7 @@ TEST_F(ReplCoordHBV1Test, JoinExistingReplSet) {
                                               << BSON("_id" << 2 << "host"
                                                             << "h2:1") << BSON("_id" << 3 << "host"
                                                                                      << "h3:1"))
-                                << "protocolVersion" << 1));
+                                << "settings" << BSON("protocolVersion" << 1)));
     init("mySet");
     addSelf(HostAndPort("h2", 1));
     const Date_t startDate = getNet()->now();
@@ -157,7 +157,7 @@ TEST_F(ReplCoordHBV1Test, DoNotJoinReplSetIfNotAMember) {
                                               << BSON("_id" << 2 << "host"
                                                             << "h2:1") << BSON("_id" << 3 << "host"
                                                                                      << "h3:1"))
-                                << "protocolVersion" << 1));
+                                << "settings" << BSON("protocolVersion" << 1)));
     init("mySet");
     addSelf(HostAndPort("h4", 1));
     const Date_t startDate = getNet()->now();
diff --git a/src/mongo/db/repl/replication_coordinator_impl_reconfig_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_reconfig_test.cpp
index d75b2c847fa..e35a58eaae9 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_reconfig_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_reconfig_test.cpp
@@ -100,7 +100,7 @@ TEST_F(ReplCoordTest, ReconfigWithUninitializableConfig) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     BSONObjBuilder result;
     ReplSetReconfigArgs args;
@@ -133,7 +133,7 @@ TEST_F(ReplCoordTest, ReconfigWithWrongReplSetName) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     BSONObjBuilder result;
     ReplSetReconfigArgs args;
@@ -164,7 +164,7 @@ TEST_F(ReplCoordTest, ReconfigValidateFails) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     BSONObjBuilder result;
     ReplSetReconfigArgs args;
@@ -227,7 +227,7 @@ TEST_F(ReplCoordTest, ReconfigQuorumCheckFails) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     Status status(ErrorCodes::InternalError, "Not Set");
     stdx::thread reconfigThread(stdx::bind(doReplSetReconfig, getReplCoord(), &status));
@@ -265,7 +265,7 @@ TEST_F(ReplCoordTest, ReconfigStoreLocalConfigDocumentFails) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     Status status(ErrorCodes::InternalError, "Not Set");
     getExternalState()->setStoreLocalConfigDocumentStatus(
@@ -290,7 +290,7 @@ TEST_F(ReplCoordTest, ReconfigWhileReconfiggingFails) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     Status status(ErrorCodes::InternalError, "Not Set");
     // first reconfig
@@ -367,7 +367,7 @@ TEST_F(ReplCoordTest, ReconfigSuccessful) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     Status status(ErrorCodes::InternalError, "Not Set");
     stdx::thread reconfigThread(stdx::bind(doReplSetReconfig, getReplCoord(), &status));
@@ -406,7 +406,7 @@ TEST_F(ReplCoordTest, ReconfigDuringHBReconfigFails) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
     ASSERT_TRUE(getReplCoord()->getMemberState().primary());
 
     // set hbreconfig to hang while in progress
@@ -461,7 +461,7 @@ TEST_F(ReplCoordTest, HBReconfigDuringReconfigFails) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
     ASSERT_TRUE(getReplCoord()->getMemberState().primary());
 
     // start reconfigThread
diff --git a/src/mongo/db/repl/replication_coordinator_impl_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
index fe2811a8127..cce2003c814 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
@@ -44,7 +44,6 @@
 #include "mongo/db/repl/read_concern_args.h"
 #include "mongo/db/repl/read_concern_response.h"
 #include "mongo/db/repl/repl_set_heartbeat_args.h"
-#include "mongo/db/repl/repl_set_heartbeat_args_v1.h"
 #include "mongo/db/repl/repl_settings.h"
 #include "mongo/db/repl/replica_set_config.h"
 #include "mongo/db/repl/replication_coordinator.h"  // ReplSetReconfigArgs
@@ -92,18 +91,6 @@ struct OpTimeWithTermZero {
     Timestamp timestamp;
 };
 
-void runSingleNodeElection(ReplicationCoordinatorImpl* replCoord) {
-    replCoord->setMyLastOptime(OpTime(Timestamp(1, 0), 0));
-    ASSERT(replCoord->setFollowerMode(MemberState::RS_SECONDARY));
-    replCoord->waitForElectionFinish_forTest();
-
-    ASSERT(replCoord->isWaitingForApplierToDrain());
-    ASSERT(replCoord->getMemberState().primary()) << replCoord->getMemberState().toString();
-
-    OperationContextReplMock txn;
-    replCoord->signalDrainComplete(&txn);
-}
-
 TEST_F(ReplCoordTest, StartupWithValidLocalConfig) {
     assertStartSuccess(BSON("_id"
                             << "mySet"
@@ -694,7 +681,7 @@ TEST_F(ReplCoordTest, AwaitReplicationReplSetBaseCases) {
 
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     statusAndDur = getReplCoord()->awaitReplication(&txn, time, writeConcern);
     ASSERT_OK(statusAndDur.status);
@@ -721,7 +708,7 @@ TEST_F(ReplCoordTest, AwaitReplicationNumberOfNodesNonBlocking) {
         HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     OpTimeWithTermZero time1(100, 1);
     OpTimeWithTermZero time2(100, 2);
@@ -809,7 +796,7 @@ TEST_F(ReplCoordTest, AwaitReplicationNamedModesNonBlocking) {
         HostAndPort("node0"));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     OpTime time1(Timestamp(100, 1), 1);
     OpTime time2(Timestamp(100, 2), 1);
@@ -977,7 +964,7 @@ TEST_F(ReplCoordTest, AwaitReplicationNumberOfNodesBlocking) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     ReplicationAwaiter awaiter(getReplCoord(), &txn);
 
@@ -1033,7 +1020,7 @@ TEST_F(ReplCoordTest, AwaitReplicationTimeout) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     ReplicationAwaiter awaiter(getReplCoord(), &txn);
 
@@ -1071,7 +1058,7 @@ TEST_F(ReplCoordTest, AwaitReplicationShutdown) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     ReplicationAwaiter awaiter(getReplCoord(), &txn);
 
@@ -1112,7 +1099,7 @@ TEST_F(ReplCoordTest, AwaitReplicationStepDown) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     ReplicationAwaiter awaiter(getReplCoord(), &txn);
 
@@ -1150,7 +1137,7 @@ TEST_F(ReplCoordTest, AwaitReplicationInterrupt) {
                        HostAndPort("node1"));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     ReplicationAwaiter awaiter(getReplCoord(), &txn);
 
@@ -1270,7 +1257,7 @@ TEST_F(StepDownTest, StepDownTimeoutAcquiringGlobalLock) {
     ASSERT_OK(getReplCoord()->setLastOptime_forTest(1, 1, optime1));
     ASSERT_OK(getReplCoord()->setLastOptime_forTest(1, 2, optime1));
 
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     // Make sure stepDown cannot grab the global shared lock
     Lock::GlobalWrite lk(txn.lockState());
@@ -1288,7 +1275,7 @@ TEST_F(StepDownTest, StepDownNoWaiting) {
     ASSERT_OK(getReplCoord()->setLastOptime_forTest(1, 1, optime1));
     ASSERT_OK(getReplCoord()->setLastOptime_forTest(1, 2, optime1));
 
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     enterNetwork();
     getNet()->runUntil(getNet()->now() + Seconds(2));
@@ -1296,7 +1283,7 @@ TEST_F(StepDownTest, StepDownNoWaiting) {
     NetworkInterfaceMock::NetworkOperationIterator noi = getNet()->getNextReadyRequest();
     RemoteCommandRequest request = noi->getRequest();
     log() << request.target.toString() << " processing " << request.cmdObj;
-    ReplSetHeartbeatArgsV1 hbArgs;
+    ReplSetHeartbeatArgs hbArgs;
     if (hbArgs.initialize(request.cmdObj).isOK()) {
         ReplSetHeartbeatResponse hbResp;
         hbResp.setSetName(hbArgs.getSetName());
@@ -1334,7 +1321,9 @@ TEST_F(ReplCoordTest, StepDownAndBackUpSingleNode) {
                                                      << "test1:1234"))),
                        HostAndPort("test1", 1234));
     OperationContextReplMock txn;
-    runSingleNodeElection(getReplCoord());
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
+
+    ASSERT_TRUE(getReplCoord()->getMemberState().primary());
     ASSERT_OK(getReplCoord()->stepDown(&txn, true, Milliseconds(0), Milliseconds(1000)));
     getNet()->enterNetwork();  // Must do this before inspecting the topocoord
     Date_t stepdownUntil = getNet()->now() + Seconds(1);
@@ -1430,7 +1419,7 @@ TEST_F(StepDownTest, StepDownNotCaughtUp) {
     runner.setWaitTime(Milliseconds(0));
     runner.setStepDownTime(Milliseconds(1000));
 
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     runner.start(&txn);
     Status status = runner.getResult();
@@ -1471,7 +1460,7 @@ TEST_F(StepDownTest, StepDownCatchUp) {
     runner.setWaitTime(Milliseconds(10000));
     runner.setStepDownTime(Milliseconds(60000));
 
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     runner.start(&txn);
 
@@ -1482,7 +1471,7 @@ TEST_F(StepDownTest, StepDownCatchUp) {
     NetworkInterfaceMock::NetworkOperationIterator noi = getNet()->getNextReadyRequest();
     RemoteCommandRequest request = noi->getRequest();
     log() << request.target.toString() << " processing " << request.cmdObj;
-    ReplSetHeartbeatArgsV1 hbArgs;
+    ReplSetHeartbeatArgs hbArgs;
     if (hbArgs.initialize(request.cmdObj).isOK()) {
         ReplSetHeartbeatResponse hbResp;
         hbResp.setSetName(hbArgs.getSetName());
@@ -1520,7 +1509,7 @@ TEST_F(StepDownTest, InterruptStepDown) {
     runner.setWaitTime(Milliseconds(10000));
     runner.setStepDownTime(Milliseconds(60000));
 
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
     ASSERT_TRUE(getReplCoord()->getMemberState().primary());
 
     runner.start(&txn);
@@ -1603,14 +1592,13 @@ TEST_F(ReplCoordTest, TestPrepareReplSetUpdatePositionCommand) {
         memberIds.insert(memberId);
         if (memberId == 0) {
             // TODO(siyuan) Update when we change replSetUpdatePosition format
-            ASSERT_EQUALS(optime1.timestamp, entry["optime"]["ts"].timestamp());
+            ASSERT_EQUALS(optime1.timestamp, entry["optime"].timestamp());
         } else if (memberId == 1) {
-            ASSERT_EQUALS(optime2.timestamp, entry["optime"]["ts"].timestamp());
+            ASSERT_EQUALS(optime2.timestamp, entry["optime"].timestamp());
         } else {
             ASSERT_EQUALS(2, memberId);
-            ASSERT_EQUALS(optime3.timestamp, entry["optime"]["ts"].timestamp());
+            ASSERT_EQUALS(optime3.timestamp, entry["optime"].timestamp());
         }
-        ASSERT_EQUALS(0, entry["optime"]["t"].Number());
     }
     ASSERT_EQUALS(3U, memberIds.size());  // Make sure we saw all 3 nodes
 }
@@ -1928,7 +1916,7 @@ TEST_F(ReplCoordTest, UpdatePositionWithConfigVersionAndMemberIdTest) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 0));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     OpTimeWithTermZero time1(100, 1);
     OpTimeWithTermZero time2(100, 2);
@@ -2028,7 +2016,7 @@ TEST_F(ReplCoordTest, AwaitReplicationReconfigSimple) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 2));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     OpTimeWithTermZero time(100, 2);
 
@@ -2090,7 +2078,7 @@ TEST_F(ReplCoordTest, AwaitReplicationReconfigNodeCountExceedsNumberOfNodes) {
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 2));
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     OpTimeWithTermZero time(100, 2);
 
@@ -2139,8 +2127,8 @@ TEST_F(ReplCoordTest, AwaitReplicationReconfigToSmallerMajority) {
                                                                          << "_id" << 4))),
                        HostAndPort("node1", 12345));
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastOptime(OpTimeWithTermZero(100, 1));
-    simulateSuccessfulV1Election();
+    getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 1), 0));
+    simulateSuccessfulElection();
 
     OpTime time(Timestamp(100, 2), 1);
 
@@ -2205,7 +2193,7 @@ TEST_F(ReplCoordTest, AwaitReplicationMajority) {
     ASSERT(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
     OpTime time(Timestamp(100, 0), 1);
     getReplCoord()->setMyLastOptime(time);
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
 
     WriteConcernOptions majorityWriteConcern;
     majorityWriteConcern.wTimeout = WriteConcernOptions::kNoWaiting;
@@ -2256,7 +2244,7 @@ TEST_F(ReplCoordTest, LastCommittedOpTime) {
     OpTime zero(Timestamp(0, 0), 0);
     OpTime time(Timestamp(100, 0), 1);
     getReplCoord()->setMyLastOptime(time);
-    simulateSuccessfulV1Election();
+    simulateSuccessfulElection();
     ASSERT_EQUALS(zero, getReplCoord()->getLastCommittedOpTime());
 
     ASSERT_OK(getReplCoord()->setLastOptime_forTest(2, 1, time));
@@ -2401,7 +2389,7 @@ TEST_F(ReplCoordTest, ReadAfterCommittedWhileShutdown) {
                                                                               << "node1:12345"
                                                                               << "_id" << 0))),
                        HostAndPort("node1", 12345));
-    runSingleNodeElection(getReplCoord());
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
 
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(10, 0), 0));
 
@@ -2422,7 +2410,7 @@ TEST_F(ReplCoordTest, ReadAfterCommittedInterrupted) {
                                                                               << "node1:12345"
                                                                               << "_id" << 0))),
                        HostAndPort("node1", 12345));
-    runSingleNodeElection(getReplCoord());
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
 
     getReplCoord()->setMyLastOptime(OpTime(Timestamp(10, 0), 0));
 
@@ -2443,12 +2431,12 @@ TEST_F(ReplCoordTest, ReadAfterCommittedGreaterOpTime) {
                                                                               << "node1:12345"
                                                                               << "_id" << 0))),
                        HostAndPort("node1", 12345));
-    runSingleNodeElection(getReplCoord());
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
 
-    getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 1));
-    getReplCoord()->onSnapshotCreate(OpTime(Timestamp(100, 0), 1), SnapshotName(1));
+    getReplCoord()->setMyLastOptime(OpTime(Timestamp(100, 0), 0));
+    getReplCoord()->onSnapshotCreate(OpTime(Timestamp(100, 0), 0), SnapshotName(1));
     auto result = getReplCoord()->waitUntilOpTime(
-        &txn, ReadConcernArgs(OpTime(Timestamp(50, 0), 1), ReadConcernLevel::kMajorityReadConcern));
+        &txn, ReadConcernArgs(OpTime(Timestamp(50, 0), 0), ReadConcernLevel::kMajorityReadConcern));
 
     ASSERT_TRUE(result.didWait());
     ASSERT_OK(result.getStatus());
@@ -2462,8 +2450,10 @@ TEST_F(ReplCoordTest, ReadAfterCommittedEqualOpTime) {
                                                                               << "node1:12345"
                                                                               << "_id" << 0))),
                        HostAndPort("node1", 12345));
-    runSingleNodeElection(getReplCoord());
-    OpTime time(Timestamp(100, 0), 1);
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
+
+
+    OpTime time(Timestamp(100, 0), 0);
     getReplCoord()->setMyLastOptime(time);
     getReplCoord()->onSnapshotCreate(time, SnapshotName(1));
     auto result = getReplCoord()->waitUntilOpTime(
@@ -2481,9 +2471,10 @@ TEST_F(ReplCoordTest, ReadAfterCommittedDeferredGreaterOpTime) {
                                                                               << "node1:12345"
                                                                               << "_id" << 0))),
                        HostAndPort("node1", 12345));
-    runSingleNodeElection(getReplCoord());
-    getReplCoord()->setMyLastOptime(OpTime(Timestamp(0, 0), 1));
-    OpTime committedOpTime(Timestamp(200, 0), 1);
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
+
+    getReplCoord()->setMyLastOptime(OpTime(Timestamp(0, 0), 0));
+    OpTime committedOpTime(Timestamp(200, 0), 0);
     auto pseudoLogOp =
         stdx::async(stdx::launch::async,
                     [this, &committedOpTime]() {
@@ -2494,7 +2485,7 @@ TEST_F(ReplCoordTest, ReadAfterCommittedDeferredGreaterOpTime) {
 
     auto result = getReplCoord()->waitUntilOpTime(
         &txn,
-        ReadConcernArgs(OpTime(Timestamp(100, 0), 1), ReadConcernLevel::kMajorityReadConcern));
+        ReadConcernArgs(OpTime(Timestamp(100, 0), 0), ReadConcernLevel::kMajorityReadConcern));
     pseudoLogOp.get();
 
     ASSERT_TRUE(result.didWait());
@@ -2509,10 +2500,11 @@ TEST_F(ReplCoordTest, ReadAfterCommittedDeferredEqualOpTime) {
                                                                               << "node1:12345"
                                                                               << "_id" << 0))),
                        HostAndPort("node1", 12345));
-    runSingleNodeElection(getReplCoord());
-    getReplCoord()->setMyLastOptime(OpTime(Timestamp(0, 0), 1));
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
+
+    getReplCoord()->setMyLastOptime(OpTime(Timestamp(0, 0), 0));
 
-    OpTime opTimeToWait(Timestamp(100, 0), 1);
+    OpTime opTimeToWait(Timestamp(100, 0), 0);
 
     auto pseudoLogOp =
         stdx::async(stdx::launch::async,
@@ -2711,13 +2703,12 @@ TEST_F(ReplCoordTest, CancelAndRescheduleElectionTimeout) {
 TEST_F(ReplCoordTest, CancelAndRescheduleElectionTimeoutWhenNotProtocolVersion1) {
     assertStartSuccess(BSON("_id"
                             << "mySet"
-                            << "protocolVersion" << 0 << "version" << 2 << "members"
-                            << BSON_ARRAY(BSON("host"
-                                               << "node1:12345"
-                                               << "_id" << 0)
-                                          << BSON("host"
-                                                  << "node2:12345"
-                                                  << "_id" << 1))),
+                            << "version" << 2 << "members" << BSON_ARRAY(BSON("host"
+                                                                              << "node1:12345"
+                                                                              << "_id" << 0)
+                                                                         << BSON("host"
+                                                                                 << "node2:12345"
+                                                                                 << "_id" << 1))),
                        HostAndPort("node1", 12345));
     ReplicationCoordinatorImpl* replCoord = getReplCoord();
     ASSERT_TRUE(replCoord->setFollowerMode(MemberState::RS_SECONDARY));
@@ -2923,7 +2914,7 @@ TEST_F(ReplCoordTest, SnapshotCommitting) {
                                                      << "test1:1234"))),
                        HostAndPort("test1", 1234));
     OperationContextReplMock txn;
-    runSingleNodeElection(getReplCoord());
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
 
     OpTime time1(Timestamp(100, 1), 1);
     OpTime time2(Timestamp(100, 2), 1);
diff --git a/src/mongo/db/repl/replication_coordinator_test_fixture.cpp b/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
index 738626eabdc..7f0b3799217 100644
--- a/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
+++ b/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
@@ -61,18 +61,6 @@ ReplicaSetConfig ReplCoordTest::assertMakeRSConfig(const BSONObj& configBson) {
     return config;
 }
 
-ReplicaSetConfig ReplCoordTest::assertMakeRSConfigV0(const BSONObj& configBson) {
-    return assertMakeRSConfig(addProtocolVersion(configBson, 0));
-}
-
-BSONObj ReplCoordTest::addProtocolVersion(const BSONObj& configDoc, int protocolVersion) {
-    BSONObjBuilder builder;
-    builder << "protocolVersion" << protocolVersion;
-    builder.appendElementsUnique(configDoc);
-    return builder.obj();
-}
-
-
 void ReplCoordTest::setUp() {
     _settings.replSet = "mySet/node1:12345,node2:54321";
 }
@@ -161,12 +149,7 @@ void ReplCoordTest::start(const HostAndPort& selfHost) {
 }
 
 void ReplCoordTest::assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost) {
-    // Set default protocol version to 1.
-    if (!configDoc.hasField("protocolVersion")) {
-        start(addProtocolVersion(configDoc, 1), selfHost);
-    } else {
-        start(configDoc, selfHost);
-    }
+    start(configDoc, selfHost);
     ASSERT_NE(MemberState::RS_STARTUP, getReplCoord()->getMemberState().s);
 }
 
diff --git a/src/mongo/db/repl/replication_coordinator_test_fixture.h b/src/mongo/db/repl/replication_coordinator_test_fixture.h
index a4023857091..7d64c936fd0 100644
--- a/src/mongo/db/repl/replication_coordinator_test_fixture.h
+++ b/src/mongo/db/repl/replication_coordinator_test_fixture.h
@@ -67,24 +67,12 @@ public:
      * Constructs a ReplicaSetConfig from the given BSON, or raises a test failure exception.
      */
     static ReplicaSetConfig assertMakeRSConfig(const BSONObj& configBSON);
-    static ReplicaSetConfig assertMakeRSConfigV0(const BSONObj& configBson);
-
-    /**
-     * Adds { protocolVersion: 0 or 1 } to the config.
-     */
-    static BSONObj addProtocolVersion(const BSONObj& configDoc, int protocolVersion);
 
 protected:
     virtual void setUp();
     virtual void tearDown();
 
     /**
-     * Asserts that calling start(configDoc, selfHost) successfully initiates the
-     * ReplicationCoordinator under test.
-     */
-    virtual void assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost);
-
-    /**
      * Gets the network mock.
      */
     executor::NetworkInterfaceMock* getNet() {
@@ -196,6 +184,12 @@ protected:
     void simulateSuccessfulV1Election();
 
     /**
+     * Asserts that calling start(configDoc, selfHost) successfully initiates the
+     * ReplicationCoordinator under test.
+     */
+    void assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost);
+
+    /**
      * Shuts down the objects under test.
      */
     void shutdown();
diff --git a/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp b/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp
index 0b0e87e7a70..63f0c80532e 100644
--- a/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp
@@ -2307,14 +2307,12 @@ TEST_F(HeartbeatResponseTestV1, ShouldRespondNegativelyToPV0ElectionCommands) {
     ASSERT_EQUALS("replset: incompatible replset protocol version: 1", status.reason());
     ASSERT_TRUE(responseBuilder.obj().isEmpty());
 
-    BSONObjBuilder electResponseBuilder;
     ReplicationCoordinator::ReplSetElectArgs electArgs;
     status = internalErrorStatus;
-    getTopoCoord().prepareElectResponse(
-        electArgs, Date_t(), OpTime(), &electResponseBuilder, &status);
+    getTopoCoord().prepareElectResponse(electArgs, Date_t(), OpTime(), &responseBuilder, &status);
     ASSERT_EQUALS(ErrorCodes::BadValue, status);
     ASSERT_EQUALS("replset: incompatible replset protocol version: 1", status.reason());
-    ASSERT_TRUE(electResponseBuilder.obj().isEmpty());
+    ASSERT_TRUE(responseBuilder.obj().isEmpty());
 }
 
 TEST_F(HeartbeatResponseTestV1, ShouldChangeSyncSourceFresherMemberIsDown) {