SERVER-28895 Remove old form of replSetUpdatePosition command

16 files changed, 120 insertions, 1014 deletions

diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index 92a5ee27814..75d416aef2f 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -1011,7 +1011,6 @@ env.Library('replica_set_messages',
                 'handshake_args.cpp',
                 'is_master_response.cpp',
                 'member_config.cpp',
-                'old_update_position_args.cpp',
                 'repl_set_heartbeat_args.cpp',
                 'repl_set_heartbeat_args_v1.cpp',
                 'repl_set_heartbeat_response.cpp',
diff --git a/src/mongo/db/repl/old_update_position_args.cpp b/src/mongo/db/repl/old_update_position_args.cpp
deleted file mode 100644
index e3c2f295d26..00000000000
--- a/src/mongo/db/repl/old_update_position_args.cpp
+++ /dev/null
@@ -1,155 +0,0 @@
-/**
- *    Copyright 2014 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#include "mongo/platform/basic.h"
-
-#include "mongo/db/repl/old_update_position_args.h"
-
-#include "mongo/base/status.h"
-#include "mongo/bson/util/bson_check.h"
-#include "mongo/bson/util/bson_extract.h"
-#include "mongo/db/jsobj.h"
-#include "mongo/db/repl/bson_extract_optime.h"
-
-namespace mongo {
-namespace repl {
-
-const char OldUpdatePositionArgs::kCommandFieldName[] = "replSetUpdatePosition";
-const char OldUpdatePositionArgs::kUpdateArrayFieldName[] = "optimes";
-const char OldUpdatePositionArgs::kMemberRIDFieldName[] = "_id";
-const char OldUpdatePositionArgs::kMemberConfigFieldName[] = "config";
-const char OldUpdatePositionArgs::kOpTimeFieldName[] = "optime";
-const char OldUpdatePositionArgs::kMemberIdFieldName[] = "memberId";
-const char OldUpdatePositionArgs::kConfigVersionFieldName[] = "cfgver";
-
-OldUpdatePositionArgs::UpdateInfo::UpdateInfo(const OID& anRid,
-                                              const OpTime& aTs,
-                                              long long aCfgver,
-                                              long long aMemberId)
-    : rid(anRid), ts(aTs), cfgver(aCfgver), memberId(aMemberId) {}
-
-namespace {
-
-const std::string kLegalUpdatePositionFieldNames[] = {
-    OldUpdatePositionArgs::kCommandFieldName, OldUpdatePositionArgs::kUpdateArrayFieldName,
-};
-
-const std::string kLegalUpdateInfoFieldNames[] = {
-    OldUpdatePositionArgs::kMemberConfigFieldName,
-    OldUpdatePositionArgs::kMemberRIDFieldName,
-    OldUpdatePositionArgs::kOpTimeFieldName,
-    OldUpdatePositionArgs::kMemberIdFieldName,
-    OldUpdatePositionArgs::kConfigVersionFieldName,
-};
-
-}  // namespace
-
-Status OldUpdatePositionArgs::initialize(const BSONObj& argsObj) {
-    Status status = bsonCheckOnlyHasFieldsForCommand(
-        "OldUpdatePositionArgs", argsObj, kLegalUpdatePositionFieldNames);
-
-    if (!status.isOK())
-        return status;
-
-    // grab the array of changes
-    BSONElement updateArray;
-    status = bsonExtractTypedField(argsObj, kUpdateArrayFieldName, Array, &updateArray);
-    if (!status.isOK())
-        return status;
-
-    // now parse each array entry into an update
-    BSONObjIterator i(updateArray.Obj());
-    while (i.more()) {
-        BSONObj entry = i.next().Obj();
-        status = bsonCheckOnlyHasFields("UpdateInfoArgs", entry, kLegalUpdateInfoFieldNames);
-        if (!status.isOK())
-            return status;
-
-        OpTime opTime;
-        if (entry[kOpTimeFieldName].isABSONObj()) {
-            // In protocol version 1, { ts: <timestamp>, t: term }
-            Status status = bsonExtractOpTimeField(entry, kOpTimeFieldName, &opTime);
-            if (!status.isOK())
-                return status;
-        } else {
-            Timestamp ts;
-            status = bsonExtractTimestampField(entry, kOpTimeFieldName, &ts);
-            if (!status.isOK())
-                return status;
-            opTime = OpTime(ts, OpTime::kUninitializedTerm);
-        }
-        if (!status.isOK())
-            return status;
-
-        // TODO(spencer): The following three fields are optional in 3.0, but should be made
-        // required or ignored in 3.0
-        long long cfgver;
-        status = bsonExtractIntegerFieldWithDefault(entry, kConfigVersionFieldName, -1, &cfgver);
-        if (!status.isOK())
-            return status;
-
-        OID rid;
-        status = bsonExtractOIDFieldWithDefault(entry, kMemberRIDFieldName, OID(), &rid);
-        if (!status.isOK())
-            return status;
-
-        long long memberID;
-        status = bsonExtractIntegerFieldWithDefault(entry, kMemberIdFieldName, -1, &memberID);
-        if (!status.isOK())
-            return status;
-
-        _updates.push_back(UpdateInfo(rid, opTime, cfgver, memberID));
-    }
-
-    return Status::OK();
-}
-
-BSONObj OldUpdatePositionArgs::toBSON() const {
-    BSONObjBuilder builder;
-    // add command name
-    builder.append(kCommandFieldName, 1);
-
-    // build array of updates
-    if (!_updates.empty()) {
-        BSONArrayBuilder updateArray(builder.subarrayStart(kUpdateArrayFieldName));
-        for (OldUpdatePositionArgs::UpdateIterator update = updatesBegin(); update != updatesEnd();
-             ++update) {
-            updateArray.append(BSON(kMemberRIDFieldName << update->rid << kOpTimeFieldName
-                                                        << update->ts.getTimestamp()
-                                                        << kConfigVersionFieldName
-                                                        << update->cfgver
-                                                        << kMemberIdFieldName
-                                                        << update->memberId));
-        }
-        updateArray.doneFast();
-    }
-    return builder.obj();
-}
-
-}  // namespace repl
-}  // namespace mongo
diff --git a/src/mongo/db/repl/old_update_position_args.h b/src/mongo/db/repl/old_update_position_args.h
deleted file mode 100644
index 01a7b52bdc4..00000000000
--- a/src/mongo/db/repl/old_update_position_args.h
+++ /dev/null
@@ -1,96 +0,0 @@
-/**
- *    Copyright (C) 2014 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#pragma once
-
-#include <vector>
-
-#include "mongo/db/jsobj.h"
-#include "mongo/db/repl/optime.h"
-
-namespace mongo {
-
-class Status;
-
-namespace repl {
-
-/**
- * Arguments to the handshake command.
- */
-class OldUpdatePositionArgs {
-public:
-    static const char kCommandFieldName[];
-    static const char kUpdateArrayFieldName[];
-    static const char kMemberRIDFieldName[];
-    static const char kMemberConfigFieldName[];
-    static const char kOpTimeFieldName[];
-    static const char kMemberIdFieldName[];
-    static const char kConfigVersionFieldName[];
-
-    struct UpdateInfo {
-        UpdateInfo(const OID& anRid, const OpTime& aTs, long long aCfgver, long long aMemberId);
-
-        OID rid;
-        OpTime ts;
-        long long cfgver;
-        long long memberId;
-    };
-
-    typedef std::vector<UpdateInfo>::const_iterator UpdateIterator;
-
-    /**
-     * Initializes this OldUpdatePositionArgs from the contents of "argsObj".
-     */
-    Status initialize(const BSONObj& argsObj);
-
-    /**
-     * Gets a begin iterator over the UpdateInfos stored in this OldUpdatePositionArgs.
-     */
-    UpdateIterator updatesBegin() const {
-        return _updates.begin();
-    }
-
-    /**
-     * Gets an end iterator over the UpdateInfos stored in this OldUpdatePositionArgs.
-     */
-    UpdateIterator updatesEnd() const {
-        return _updates.end();
-    }
-
-    /**
-     * Returns a BSONified version of the object.
-     * _updates is only included if it is not empty.
-     */
-    BSONObj toBSON() const;
-
-private:
-    std::vector<UpdateInfo> _updates;
-};
-
-}  // namespace repl
-}  // namespace mongo
diff --git a/src/mongo/db/repl/repl_set_commands.cpp b/src/mongo/db/repl/repl_set_commands.cpp
index 5bc28841697..ebee2285b3e 100644
--- a/src/mongo/db/repl/repl_set_commands.cpp
+++ b/src/mongo/db/repl/repl_set_commands.cpp
@@ -49,7 +49,6 @@
 #include "mongo/db/lasterror.h"
 #include "mongo/db/op_observer.h"
 #include "mongo/db/repl/drop_pending_collection_reaper.h"
-#include "mongo/db/repl/old_update_position_args.h"
 #include "mongo/db/repl/oplog.h"
 #include "mongo/db/repl/repl_set_heartbeat_args.h"
 #include "mongo/db/repl/repl_set_heartbeat_args_v1.h"
@@ -657,26 +656,12 @@ public:
 
         status = args.initialize(cmdObj);
         if (status.isOK()) {
-            // v3.2.4+ style replSetUpdatePosition command.
             status = replCoord->processReplSetUpdatePosition(args, &configVersion);
 
             if (status == ErrorCodes::InvalidReplicaSetConfig) {
                 result.append("configVersion", configVersion);
             }
             return appendCommandStatus(result, status);
-        } else if (status == ErrorCodes::NoSuchKey) {
-            // Pre-3.2.4 style replSetUpdatePosition command.
-            OldUpdatePositionArgs oldArgs;
-            status = oldArgs.initialize(cmdObj);
-            if (!status.isOK())
-                return appendCommandStatus(result, status);
-
-            status = replCoord->processReplSetUpdatePosition(oldArgs, &configVersion);
-
-            if (status == ErrorCodes::InvalidReplicaSetConfig) {
-                result.append("configVersion", configVersion);
-            }
-            return appendCommandStatus(result, status);
         } else {
             // Parsing error from UpdatePositionArgs.
             return appendCommandStatus(result, status);
diff --git a/src/mongo/db/repl/replication_coordinator.h b/src/mongo/db/repl/replication_coordinator.h
index bb2d725b6e8..3fa44e8a026 100644
--- a/src/mongo/db/repl/replication_coordinator.h
+++ b/src/mongo/db/repl/replication_coordinator.h
@@ -67,7 +67,6 @@ namespace repl {
 class BackgroundSync;
 class HandshakeArgs;
 class IsMasterResponse;
-class OldUpdatePositionArgs;
 class OplogReader;
 class OpTime;
 class ReadConcernArgs;
@@ -521,17 +520,11 @@ public:
      */
     virtual void signalUpstreamUpdater() = 0;
 
-    enum class ReplSetUpdatePositionCommandStyle {
-        kNewStyle,
-        kOldStyle  // Pre-3.2.4 servers.
-    };
-
     /**
      * Prepares a BSONObj describing an invocation of the replSetUpdatePosition command that can
      * be sent to this node's sync source to update it about our progress in replication.
      */
-    virtual StatusWith<BSONObj> prepareReplSetUpdatePositionCommand(
-        ReplSetUpdatePositionCommandStyle commandStyle) const = 0;
+    virtual StatusWith<BSONObj> prepareReplSetUpdatePositionCommand() const = 0;
 
     enum class ReplSetGetStatusResponseStyle { kBasic, kInitialSync };
 
@@ -700,12 +693,7 @@ public:
      * were applied.
      * "configVersion" will be populated with our config version if and only if we return
      * InvalidReplicaSetConfig.
-     *
-     * The OldUpdatePositionArgs version provides support for the pre-3.2.4 format of
-     * UpdatePositionArgs.
      */
-    virtual Status processReplSetUpdatePosition(const OldUpdatePositionArgs& updates,
-                                                long long* configVersion) = 0;
     virtual Status processReplSetUpdatePosition(const UpdatePositionArgs& updates,
                                                 long long* configVersion) = 0;
 
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index bc178dc9ecf..3dd9826e018 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -52,7 +52,6 @@
 #include "mongo/db/repl/is_master_response.h"
 #include "mongo/db/repl/last_vote.h"
 #include "mongo/db/repl/member_data.h"
-#include "mongo/db/repl/old_update_position_args.h"
 #include "mongo/db/repl/read_concern_args.h"
 #include "mongo/db/repl/repl_client_info.h"
 #include "mongo/db/repl/repl_set_config_checks.h"
@@ -1374,73 +1373,6 @@ Status ReplicationCoordinatorImpl::setLastAppliedOptime_forTest(long long cfgVer
     return status;
 }
 
-Status ReplicationCoordinatorImpl::_setLastOptime_inlock(
-    const OldUpdatePositionArgs::UpdateInfo& args, long long* configVersion) {
-    if (_selfIndex == -1) {
-        // Ignore updates when we're in state REMOVED
-        return Status(ErrorCodes::NotMasterOrSecondary,
-                      "Received replSetUpdatePosition command but we are in state REMOVED");
-    }
-    invariant(getReplicationMode() == modeReplSet);
-
-    if (args.memberId < 0) {
-        std::string errmsg = str::stream()
-            << "Received replSetUpdatePosition for node with memberId " << args.memberId
-            << " which is negative and therefore invalid";
-        LOG(1) << errmsg;
-        return Status(ErrorCodes::NodeNotFound, errmsg);
-    }
-
-    if (args.memberId == _rsConfig.getMemberAt(_selfIndex).getId()) {
-        // Do not let remote nodes tell us what our optime is.
-        return Status::OK();
-    }
-
-    LOG(2) << "received notification that node with memberID " << args.memberId
-           << " in config with version " << args.cfgver
-           << " has durably reached optime: " << args.ts;
-
-    if (args.cfgver != _rsConfig.getConfigVersion()) {
-        std::string errmsg = str::stream()
-            << "Received replSetUpdatePosition for node with memberId " << args.memberId
-            << " whose config version of " << args.cfgver << " doesn't match our config version of "
-            << _rsConfig.getConfigVersion();
-        LOG(1) << errmsg;
-        *configVersion = _rsConfig.getConfigVersion();
-        return Status(ErrorCodes::InvalidReplicaSetConfig, errmsg);
-    }
-
-    auto* memberData = _topCoord->findMemberDataByMemberId(args.memberId);
-    if (!memberData) {
-        invariant(!_rsConfig.findMemberByID(args.memberId));
-
-        std::string errmsg = str::stream()
-            << "Received replSetUpdatePosition for node with memberId " << args.memberId
-            << " which doesn't exist in our config";
-        LOG(1) << errmsg;
-        return Status(ErrorCodes::NodeNotFound, errmsg);
-    }
-
-    invariant(args.memberId == memberData->getMemberId());
-
-    LOG(3) << "Node with memberID " << args.memberId << " has durably applied operations through "
-           << memberData->getLastDurableOpTime() << " and has applied operations through "
-           << memberData->getLastAppliedOpTime()
-           << "; updating to new durable operation with timestamp " << args.ts;
-
-    auto now(_replExecutor->now());
-    bool advancedOpTime = memberData->advanceLastAppliedOpTime(args.ts, now);
-    advancedOpTime = memberData->advanceLastDurableOpTime(args.ts, now) || advancedOpTime;
-
-    // Only update committed optime if the remote optimes increased.
-    if (advancedOpTime) {
-        _updateLastCommittedOpTime_inlock();
-    }
-
-    _cancelAndRescheduleLivenessUpdate_inlock(args.memberId);
-    return Status::OK();
-}
-
 Status ReplicationCoordinatorImpl::_setLastOptime_inlock(const UpdatePositionArgs::UpdateInfo& args,
                                                          long long* configVersion) {
     if (_selfIndex == -1) {
@@ -2060,11 +1992,10 @@ Status ReplicationCoordinatorImpl::resyncData(OperationContext* opCtx, bool wait
     return Status::OK();
 }
 
-StatusWith<BSONObj> ReplicationCoordinatorImpl::prepareReplSetUpdatePositionCommand(
-    ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle) const {
+StatusWith<BSONObj> ReplicationCoordinatorImpl::prepareReplSetUpdatePositionCommand() const {
     stdx::lock_guard<stdx::mutex> lock(_mutex);
     return _topCoord->prepareReplSetUpdatePositionCommand(
-        commandStyle, _getCurrentCommittedSnapshotOpTime_inlock());
+        _getCurrentCommittedSnapshotOpTime_inlock());
 }
 
 Status ReplicationCoordinatorImpl::processReplSetGetStatus(
@@ -2981,29 +2912,6 @@ void ReplicationCoordinatorImpl::_wakeReadyWaiters_inlock() {
     });
 }
 
-Status ReplicationCoordinatorImpl::processReplSetUpdatePosition(
-    const OldUpdatePositionArgs& updates, long long* configVersion) {
-    stdx::unique_lock<stdx::mutex> lock(_mutex);
-    Status status = Status::OK();
-    bool somethingChanged = false;
-    for (OldUpdatePositionArgs::UpdateIterator update = updates.updatesBegin();
-         update != updates.updatesEnd();
-         ++update) {
-        status = _setLastOptime_inlock(*update, configVersion);
-        if (!status.isOK()) {
-            break;
-        }
-        somethingChanged = true;
-    }
-
-    if (somethingChanged && !_getMemberState_inlock().primary()) {
-        lock.unlock();
-        // Must do this outside _mutex
-        _externalState->forwardSlaveProgress();
-    }
-    return status;
-}
-
 Status ReplicationCoordinatorImpl::processReplSetUpdatePosition(const UpdatePositionArgs& updates,
                                                                 long long* configVersion) {
     stdx::unique_lock<stdx::mutex> lock(_mutex);
diff --git a/src/mongo/db/repl/replication_coordinator_impl.h b/src/mongo/db/repl/replication_coordinator_impl.h
index 1e97a82db0f..ab3873868e6 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.h
+++ b/src/mongo/db/repl/replication_coordinator_impl.h
@@ -37,7 +37,6 @@
 #include "mongo/db/concurrency/d_concurrency.h"
 #include "mongo/db/repl/initial_syncer.h"
 #include "mongo/db/repl/member_state.h"
-#include "mongo/db/repl/old_update_position_args.h"
 #include "mongo/db/repl/optime.h"
 #include "mongo/db/repl/repl_set_config.h"
 #include "mongo/db/repl/replication_coordinator.h"
@@ -192,8 +191,7 @@ public:
 
     virtual Status resyncData(OperationContext* opCtx, bool waitUntilCompleted) override;
 
-    virtual StatusWith<BSONObj> prepareReplSetUpdatePositionCommand(
-        ReplSetUpdatePositionCommandStyle commandStyle) const override;
+    virtual StatusWith<BSONObj> prepareReplSetUpdatePositionCommand() const override;
 
     virtual Status processReplSetGetStatus(BSONObjBuilder* result,
                                            ReplSetGetStatusResponseStyle responseStyle) override;
@@ -239,8 +237,6 @@ public:
     virtual Status processReplSetElect(const ReplSetElectArgs& args,
                                        BSONObjBuilder* response) override;
 
-    virtual Status processReplSetUpdatePosition(const OldUpdatePositionArgs& updates,
-                                                long long* configVersion) override;
     virtual Status processReplSetUpdatePosition(const UpdatePositionArgs& updates,
                                                 long long* configVersion) override;
 
@@ -658,12 +654,7 @@ private:
      * This is only valid to call on replica sets.
      * "configVersion" will be populated with our config version if it and the configVersion
      * of "args" differ.
-     *
-     * The OldUpdatePositionArgs version provides support for the pre-3.2.4 format of
-     * UpdatePositionArgs.
      */
-    Status _setLastOptime_inlock(const OldUpdatePositionArgs::UpdateInfo& args,
-                                 long long* configVersion);
     Status _setLastOptime_inlock(const UpdatePositionArgs::UpdateInfo& args,
                                  long long* configVersion);
 
diff --git a/src/mongo/db/repl/replication_coordinator_impl_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
index c8058823ab8..3cf40cda0d4 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
@@ -41,7 +41,6 @@
 #include "mongo/db/repl/bson_extract_optime.h"
 #include "mongo/db/repl/handshake_args.h"
 #include "mongo/db/repl/is_master_response.h"
-#include "mongo/db/repl/old_update_position_args.h"
 #include "mongo/db/repl/optime.h"
 #include "mongo/db/repl/read_concern_args.h"
 #include "mongo/db/repl/repl_client_info.h"
@@ -2270,8 +2269,7 @@ TEST_F(ReplCoordTest, NodeIncludesOtherMembersProgressInUpdatePositionCommand) {
     ASSERT_OK(getReplCoord()->setLastDurableOptime_forTest(1, 3, optime1));
 
     // Check that the proper BSON is generated for the replSetUpdatePositionCommand
-    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle));
+    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand());
 
     ASSERT_EQUALS(3, cmd.nFields());
     ASSERT_EQUALS(UpdatePositionArgs::kCommandFieldName, cmd.firstElement().fieldNameStringData());
@@ -2321,60 +2319,6 @@ TEST_F(ReplCoordTest, NodeIncludesOtherMembersProgressInUpdatePositionCommand) {
     ASSERT_EQUALS(4U, memberIds.size());  // Make sure we saw all 4 nodes
 }
 
-TEST_F(ReplCoordTest, NodeIncludesOtherMembersProgressInOldUpdatePositionCommand) {
-    init("mySet/test1:1234,test2:1234,test3:1234");
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 1
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 0 << "host"
-                                                     << "test1:1234")
-                                          << BSON("_id" << 1 << "host"
-                                                        << "test2:1234")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "test3:1234"))),
-                       HostAndPort("test1", 1234));
-    OpTimeWithTermOne optime1(100, 1);
-    OpTimeWithTermOne optime2(100, 2);
-    OpTimeWithTermOne optime3(2, 1);
-    getReplCoord()->setMyLastAppliedOpTime(optime1);
-    getReplCoord()->setMyLastDurableOpTime(optime1);
-    ASSERT_OK(getReplCoord()->setLastAppliedOptime_forTest(1, 1, optime2));
-    ASSERT_OK(getReplCoord()->setLastDurableOptime_forTest(1, 1, optime2));
-    ASSERT_OK(getReplCoord()->setLastAppliedOptime_forTest(1, 2, optime3));
-    ASSERT_OK(getReplCoord()->setLastDurableOptime_forTest(1, 2, optime3));
-
-    // Check that the proper BSON is generated for the replSetUpdatePositionCommand
-    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle));
-
-    ASSERT_EQUALS(2, cmd.nFields());
-    ASSERT_EQUALS(OldUpdatePositionArgs::kCommandFieldName,
-                  cmd.firstElement().fieldNameStringData());
-
-    std::set<long long> memberIds;
-    BSONForEach(entryElement, cmd[OldUpdatePositionArgs::kUpdateArrayFieldName].Obj()) {
-        BSONObj entry = entryElement.Obj();
-        long long memberId = entry[OldUpdatePositionArgs::kMemberIdFieldName].Number();
-        memberIds.insert(memberId);
-        if (memberId == 0) {
-            // TODO(siyuan) Update when we change replSetUpdatePosition format
-            ASSERT_EQUALS(optime1.timestamp,
-                          entry[OldUpdatePositionArgs::kOpTimeFieldName]["ts"].timestamp());
-        } else if (memberId == 1) {
-            ASSERT_EQUALS(optime2.timestamp,
-                          entry[OldUpdatePositionArgs::kOpTimeFieldName]["ts"].timestamp());
-        } else {
-            ASSERT_EQUALS(2, memberId);
-            ASSERT_EQUALS(optime3.timestamp,
-                          entry[OldUpdatePositionArgs::kOpTimeFieldName]["ts"].timestamp());
-        }
-        ASSERT_EQUALS(1, entry[OldUpdatePositionArgs::kOpTimeFieldName]["t"].Number());
-    }
-    ASSERT_EQUALS(3U, memberIds.size());  // Make sure we saw all 3 nodes
-}
-
 TEST_F(ReplCoordTest,
        NodeReturnsOperationFailedWhenSettingMaintenanceModeFalseWhenItHasNotBeenSetTrue) {
     init("mySet/test1:1234,test2:1234,test3:1234");
@@ -2947,63 +2891,6 @@ TEST_F(ReplCoordTest, DoNotProcessSelfWhenUpdatePositionContainsInfoAboutSelf) {
                   getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
 }
 
-TEST_F(ReplCoordTest, DoNotProcessSelfWhenOldUpdatePositionContainsInfoAboutSelf) {
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("host"
-                                               << "node1:12345"
-                                               << "_id"
-                                               << 0)
-                                          << BSON("host"
-                                                  << "node2:12345"
-                                                  << "_id"
-                                                  << 1)
-                                          << BSON("host"
-                                                  << "node3:12345"
-                                                  << "_id"
-                                                  << 2))),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastAppliedOpTime(OpTimeWithTermOne(100, 0));
-    getReplCoord()->setMyLastDurableOpTime(OpTimeWithTermOne(100, 0));
-    simulateSuccessfulV1Election();
-
-    OpTimeWithTermOne time1(100, 1);
-    OpTimeWithTermOne time2(100, 2);
-    OpTimeWithTermOne staleTime(10, 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    getReplCoord()->setMyLastDurableOpTime(time1);
-
-    WriteConcernOptions writeConcern;
-    writeConcern.wTimeout = WriteConcernOptions::kNoWaiting;
-    writeConcern.wNumNodes = 1;
-
-    auto opCtx = makeOperationContext();
-
-
-    ASSERT_EQUALS(ErrorCodes::WriteConcernFailed,
-                  getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
-
-    // receive updatePosition containing ourself, should not process the update for self
-    OldUpdatePositionArgs args;
-    ASSERT_OK(args.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
-                                   << 1
-                                   << OldUpdatePositionArgs::kUpdateArrayFieldName
-                                   << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                      << 2
-                                                      << OldUpdatePositionArgs::kMemberIdFieldName
-                                                      << 0
-                                                      << OldUpdatePositionArgs::kOpTimeFieldName
-                                                      << time2.timestamp)))));
-
-    ASSERT_OK(getReplCoord()->processReplSetUpdatePosition(args, 0));
-    ASSERT_EQUALS(ErrorCodes::WriteConcernFailed,
-                  getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
-}
-
 TEST_F(ReplCoordTest, DoNotProcessUpdatePositionWhenItsConfigVersionIsIncorrect) {
     assertStartSuccess(BSON("_id"
                             << "mySet"
@@ -3061,62 +2948,6 @@ TEST_F(ReplCoordTest, DoNotProcessUpdatePositionWhenItsConfigVersionIsIncorrect)
                   getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
 }
 
-TEST_F(ReplCoordTest, DoNotProcessOldUpdatePositionWhenItsConfigVersionIsIncorrect) {
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("host"
-                                               << "node1:12345"
-                                               << "_id"
-                                               << 0)
-                                          << BSON("host"
-                                                  << "node2:12345"
-                                                  << "_id"
-                                                  << 1)
-                                          << BSON("host"
-                                                  << "node3:12345"
-                                                  << "_id"
-                                                  << 2))),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastAppliedOpTime(OpTimeWithTermOne(100, 0));
-    getReplCoord()->setMyLastDurableOpTime(OpTimeWithTermOne(100, 0));
-    simulateSuccessfulV1Election();
-
-    OpTimeWithTermOne time1(100, 1);
-    OpTimeWithTermOne time2(100, 2);
-    OpTimeWithTermOne staleTime(10, 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    getReplCoord()->setMyLastDurableOpTime(time1);
-
-    WriteConcernOptions writeConcern;
-    writeConcern.wTimeout = WriteConcernOptions::kNoWaiting;
-    writeConcern.wNumNodes = 1;
-
-    // receive updatePosition with incorrect config version
-    OldUpdatePositionArgs args;
-    ASSERT_OK(args.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
-                                   << 1
-                                   << OldUpdatePositionArgs::kUpdateArrayFieldName
-                                   << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                      << 3
-                                                      << OldUpdatePositionArgs::kMemberIdFieldName
-                                                      << 1
-                                                      << OldUpdatePositionArgs::kOpTimeFieldName
-                                                      << time2.timestamp)))));
-
-    auto opCtx = makeOperationContext();
-
-
-    long long cfgver;
-    ASSERT_EQUALS(ErrorCodes::InvalidReplicaSetConfig,
-                  getReplCoord()->processReplSetUpdatePosition(args, &cfgver));
-    ASSERT_EQUALS(ErrorCodes::WriteConcernFailed,
-                  getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
-}
-
 TEST_F(ReplCoordTest, DoNotProcessUpdatePositionOfMembersWhoseIdsAreNotInTheConfig) {
     assertStartSuccess(BSON("_id"
                             << "mySet"
@@ -3172,60 +3003,6 @@ TEST_F(ReplCoordTest, DoNotProcessUpdatePositionOfMembersWhoseIdsAreNotInTheConf
                   getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
 }
 
-TEST_F(ReplCoordTest, DoNotProcessOldUpdatePositionOfMembersWhoseIdsAreNotInTheConfig) {
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("host"
-                                               << "node1:12345"
-                                               << "_id"
-                                               << 0)
-                                          << BSON("host"
-                                                  << "node2:12345"
-                                                  << "_id"
-                                                  << 1)
-                                          << BSON("host"
-                                                  << "node3:12345"
-                                                  << "_id"
-                                                  << 2))),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastAppliedOpTime(OpTimeWithTermOne(100, 0));
-    getReplCoord()->setMyLastDurableOpTime(OpTimeWithTermOne(100, 0));
-    simulateSuccessfulV1Election();
-
-    OpTimeWithTermOne time1(100, 1);
-    OpTimeWithTermOne time2(100, 2);
-    OpTimeWithTermOne staleTime(10, 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    getReplCoord()->setMyLastDurableOpTime(time1);
-
-    WriteConcernOptions writeConcern;
-    writeConcern.wTimeout = WriteConcernOptions::kNoWaiting;
-    writeConcern.wNumNodes = 1;
-
-    // receive updatePosition with nonexistent member id
-    OldUpdatePositionArgs args;
-    ASSERT_OK(args.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
-                                   << 1
-                                   << OldUpdatePositionArgs::kUpdateArrayFieldName
-                                   << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                      << 2
-                                                      << OldUpdatePositionArgs::kMemberIdFieldName
-                                                      << 9
-                                                      << OldUpdatePositionArgs::kOpTimeFieldName
-                                                      << time2.timestamp)))));
-
-    auto opCtx = makeOperationContext();
-
-
-    ASSERT_EQUALS(ErrorCodes::NodeNotFound, getReplCoord()->processReplSetUpdatePosition(args, 0));
-    ASSERT_EQUALS(ErrorCodes::WriteConcernFailed,
-                  getReplCoord()->awaitReplication(opCtx.get(), time2, writeConcern).status);
-}
-
 TEST_F(ReplCoordTest,
        ProcessUpdateWhenUpdatePositionContainsOnlyConfigVersionAndMemberIdsWithoutRIDs) {
     assertStartSuccess(BSON("_id"
@@ -3264,23 +3041,27 @@ TEST_F(ReplCoordTest,
     // receive a good update position
     getReplCoord()->setMyLastAppliedOpTime(time2);
     getReplCoord()->setMyLastDurableOpTime(time2);
-    OldUpdatePositionArgs args;
+    UpdatePositionArgs args;
     ASSERT_OK(
-        args.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
+        args.initialize(BSON(UpdatePositionArgs::kCommandFieldName
                              << 1
-                             << OldUpdatePositionArgs::kUpdateArrayFieldName
-                             << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                             << UpdatePositionArgs::kUpdateArrayFieldName
+                             << BSON_ARRAY(BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                 << 2
-                                                << OldUpdatePositionArgs::kMemberIdFieldName
+                                                << UpdatePositionArgs::kMemberIdFieldName
                                                 << 1
-                                                << OldUpdatePositionArgs::kOpTimeFieldName
-                                                << time2.timestamp)
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                                                << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                << time2.asOpTime().toBSON()
+                                                << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                << time2.asOpTime().toBSON())
+                                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                    << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
+                                                   << UpdatePositionArgs::kMemberIdFieldName
                                                    << 2
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << time2.timestamp)))));
+                                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                   << time2.asOpTime().toBSON()
+                                                   << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                   << time2.asOpTime().toBSON())))));
 
     auto opCtx = makeOperationContext();
 
@@ -5198,8 +4979,7 @@ TEST_F(ReplCoordTest, OnlyForwardSyncProgressForOtherNodesWhenTheNodesAreBelieve
     ASSERT_OK(getReplCoord()->setLastDurableOptime_forTest(1, 1, optime));
 
     // Check that we have two entries in our UpdatePosition (us and node 1).
-    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle));
+    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand());
     std::set<long long> memberIds;
     BSONForEach(entryElement, cmd[UpdatePositionArgs::kUpdateArrayFieldName].Obj()) {
         BSONObj entry = entryElement.Obj();
@@ -5216,21 +4996,6 @@ TEST_F(ReplCoordTest, OnlyForwardSyncProgressForOtherNodesWhenTheNodesAreBelieve
     }
     ASSERT_EQUALS(2U, memberIds.size());
 
-    // Check that this true for old style (pre-3.2.4) UpdatePosition as well.
-    BSONObj cmd2 = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle));
-    std::set<long long> memberIds2;
-    BSONForEach(entryElement, cmd2[OldUpdatePositionArgs::kUpdateArrayFieldName].Obj()) {
-        BSONObj entry = entryElement.Obj();
-        long long memberId = entry[OldUpdatePositionArgs::kMemberIdFieldName].Number();
-        memberIds2.insert(memberId);
-        OpTime entryOpTime;
-        bsonExtractOpTimeField(entry, OldUpdatePositionArgs::kOpTimeFieldName, &entryOpTime)
-            .transitional_ignore();
-        ASSERT_EQUALS(optime, entryOpTime);
-    }
-    ASSERT_EQUALS(2U, memberIds2.size());
-
     // Advance the clock far enough to cause the other node to be marked as DOWN.
     const Date_t startDate = getNet()->now();
     const Date_t endDate = startDate + Milliseconds(2000);
@@ -5245,13 +5010,12 @@ TEST_F(ReplCoordTest, OnlyForwardSyncProgressForOtherNodesWhenTheNodesAreBelieve
 
     // Check there is one entry in our UpdatePosition, since we shouldn't forward for a
     // DOWN node.
-    BSONObj cmd3 = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle));
-    std::set<long long> memberIds3;
-    BSONForEach(entryElement, cmd3[UpdatePositionArgs::kUpdateArrayFieldName].Obj()) {
+    BSONObj cmd2 = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand());
+    std::set<long long> memberIds2;
+    BSONForEach(entryElement, cmd2[UpdatePositionArgs::kUpdateArrayFieldName].Obj()) {
         BSONObj entry = entryElement.Obj();
         long long memberId = entry[UpdatePositionArgs::kMemberIdFieldName].Number();
-        memberIds3.insert(memberId);
+        memberIds2.insert(memberId);
         OpTime appliedOpTime;
         OpTime durableOpTime;
         bsonExtractOpTimeField(entry, UpdatePositionArgs::kAppliedOpTimeFieldName, &appliedOpTime)
@@ -5261,25 +5025,10 @@ TEST_F(ReplCoordTest, OnlyForwardSyncProgressForOtherNodesWhenTheNodesAreBelieve
             .transitional_ignore();
         ASSERT_EQUALS(optime, durableOpTime);
     }
-    ASSERT_EQUALS(1U, memberIds3.size());
-
-    // Check that this true for old style (pre-3.2.4) UpdatePosition as well.
-    BSONObj cmd4 = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle));
-    std::set<long long> memberIds4;
-    BSONForEach(entryElement, cmd4[OldUpdatePositionArgs::kUpdateArrayFieldName].Obj()) {
-        BSONObj entry = entryElement.Obj();
-        long long memberId = entry[OldUpdatePositionArgs::kMemberIdFieldName].Number();
-        memberIds4.insert(memberId);
-        OpTime entryOpTime;
-        bsonExtractOpTimeField(entry, OldUpdatePositionArgs::kOpTimeFieldName, &entryOpTime)
-            .transitional_ignore();
-        ASSERT_EQUALS(optime, entryOpTime);
-    }
-    ASSERT_EQUALS(1U, memberIds4.size());
+    ASSERT_EQUALS(1U, memberIds2.size());
 }
 
-TEST_F(ReplCoordTest, NewStyleUpdatePositionCmdHasMetadata) {
+TEST_F(ReplCoordTest, UpdatePositionCmdHasMetadata) {
     assertStartSuccess(
         BSON("_id"
              << "mySet"
@@ -5307,8 +5056,7 @@ TEST_F(ReplCoordTest, NewStyleUpdatePositionCmdHasMetadata) {
     getReplCoord()->processReplSetMetadata(syncSourceMetadata);
     getReplCoord()->advanceCommitPoint(optime);
 
-    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle));
+    BSONObj cmd = unittest::assertGet(getReplCoord()->prepareReplSetUpdatePositionCommand());
     auto metadata = unittest::assertGet(rpc::ReplSetMetadata::readFromMetadata(cmd));
     ASSERT_EQUALS(metadata.getTerm(), getReplCoord()->getTerm());
     ASSERT_EQUALS(metadata.getLastOpVisible(), optime);
@@ -5355,58 +5103,70 @@ TEST_F(ReplCoordTest, StepDownWhenHandleLivenessTimeoutMarksAMajorityOfVotingNod
     getReplCoord()->setMyLastDurableOpTime(startingOpTime);
 
     // Receive notification that every node is up.
-    OldUpdatePositionArgs args;
+    UpdatePositionArgs args;
     ASSERT_OK(
-        args.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
+        args.initialize(BSON(UpdatePositionArgs::kCommandFieldName
                              << 1
-                             << OldUpdatePositionArgs::kUpdateArrayFieldName
-                             << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                             << UpdatePositionArgs::kUpdateArrayFieldName
+                             << BSON_ARRAY(BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                 << 2
-                                                << OldUpdatePositionArgs::kMemberIdFieldName
+                                                << UpdatePositionArgs::kMemberIdFieldName
                                                 << 1
-                                                << OldUpdatePositionArgs::kOpTimeFieldName
-                                                << startingOpTime.getTimestamp())
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                                                << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                << startingOpTime.toBSON()
+                                                << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                << startingOpTime.toBSON())
+                                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                    << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
+                                                   << UpdatePositionArgs::kMemberIdFieldName
                                                    << 2
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << startingOpTime.getTimestamp())
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                   << startingOpTime.toBSON()
+                                                   << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                   << startingOpTime.toBSON())
+                                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                    << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
+                                                   << UpdatePositionArgs::kMemberIdFieldName
                                                    << 3
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << startingOpTime.getTimestamp())
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                   << startingOpTime.toBSON()
+                                                   << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                   << startingOpTime.toBSON())
+                                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                    << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
+                                                   << UpdatePositionArgs::kMemberIdFieldName
                                                    << 4
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << startingOpTime.getTimestamp())))));
+                                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                   << startingOpTime.toBSON()
+                                                   << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                   << startingOpTime.toBSON())))));
 
     ASSERT_OK(getReplCoord()->processReplSetUpdatePosition(args, 0));
     // Become PRIMARY.
     simulateSuccessfulV1Election();
 
     // Keep two nodes alive.
-    OldUpdatePositionArgs args1;
+    UpdatePositionArgs args1;
     ASSERT_OK(
-        args1.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
+        args1.initialize(BSON(UpdatePositionArgs::kCommandFieldName
                               << 1
-                              << OldUpdatePositionArgs::kUpdateArrayFieldName
-                              << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                              << UpdatePositionArgs::kUpdateArrayFieldName
+                              << BSON_ARRAY(BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                  << 2
-                                                 << OldUpdatePositionArgs::kMemberIdFieldName
+                                                 << UpdatePositionArgs::kMemberIdFieldName
                                                  << 1
-                                                 << OldUpdatePositionArgs::kOpTimeFieldName
-                                                 << startingOpTime.getTimestamp())
-                                            << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                                                 << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                 << startingOpTime.toBSON()
+                                                 << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                 << startingOpTime.toBSON())
+                                            << BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                     << 2
-                                                    << OldUpdatePositionArgs::kMemberIdFieldName
+                                                    << UpdatePositionArgs::kMemberIdFieldName
                                                     << 2
-                                                    << OldUpdatePositionArgs::kOpTimeFieldName
-                                                    << startingOpTime.getTimestamp())))));
+                                                    << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                    << startingOpTime.toBSON()
+                                                    << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                    << startingOpTime.toBSON())))));
     ASSERT_OK(getReplCoord()->processReplSetUpdatePosition(args1, 0));
 
     // Confirm that the node remains PRIMARY after the other two nodes are marked DOWN.
@@ -5417,17 +5177,19 @@ TEST_F(ReplCoordTest, StepDownWhenHandleLivenessTimeoutMarksAMajorityOfVotingNod
     ASSERT_EQUALS(MemberState::RS_PRIMARY, getReplCoord()->getMemberState().s);
 
     // Keep one node alive via two methods (UpdatePosition and requestHeartbeat).
-    OldUpdatePositionArgs args2;
+    UpdatePositionArgs args2;
     ASSERT_OK(
-        args2.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
+        args2.initialize(BSON(UpdatePositionArgs::kCommandFieldName
                               << 1
-                              << OldUpdatePositionArgs::kUpdateArrayFieldName
-                              << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
+                              << UpdatePositionArgs::kUpdateArrayFieldName
+                              << BSON_ARRAY(BSON(UpdatePositionArgs::kConfigVersionFieldName
                                                  << 2
-                                                 << OldUpdatePositionArgs::kMemberIdFieldName
+                                                 << UpdatePositionArgs::kMemberIdFieldName
                                                  << 1
-                                                 << OldUpdatePositionArgs::kOpTimeFieldName
-                                                 << startingOpTime.getTimestamp())))));
+                                                 << UpdatePositionArgs::kDurableOpTimeFieldName
+                                                 << startingOpTime.toBSON()
+                                                 << UpdatePositionArgs::kAppliedOpTimeFieldName
+                                                 << startingOpTime.toBSON())))));
     ASSERT_OK(getReplCoord()->processReplSetUpdatePosition(args2, 0));
 
     ReplSetHeartbeatArgsV1 hbArgs;
@@ -5530,150 +5292,6 @@ TEST_F(ReplCoordTest, WaitForDrainFinish) {
     ASSERT_OK(replCoord->waitForDrainFinish(Milliseconds(0)));
 }
 
-TEST_F(ReplCoordTest, UpdatePositionArgsReturnsNoSuchKeyWhenParsingOldUpdatePositionArgs) {
-    OldUpdatePositionArgs args;
-    UpdatePositionArgs args2;
-    OpTime opTime = OpTime(Timestamp(100, 1), 0);
-    ASSERT_EQUALS(
-        ErrorCodes::NoSuchKey,
-        args2.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
-                              << 1
-                              << OldUpdatePositionArgs::kUpdateArrayFieldName
-                              << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                 << 2
-                                                 << OldUpdatePositionArgs::kMemberIdFieldName
-                                                 << 1
-                                                 << OldUpdatePositionArgs::kOpTimeFieldName
-                                                 << opTime.getTimestamp())
-                                            << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                    << 2
-                                                    << OldUpdatePositionArgs::kMemberIdFieldName
-                                                    << 2
-                                                    << OldUpdatePositionArgs::kOpTimeFieldName
-                                                    << opTime.getTimestamp())
-                                            << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                    << 2
-                                                    << OldUpdatePositionArgs::kMemberIdFieldName
-                                                    << 3
-                                                    << OldUpdatePositionArgs::kOpTimeFieldName
-                                                    << opTime.getTimestamp())
-                                            << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                    << 2
-                                                    << OldUpdatePositionArgs::kMemberIdFieldName
-                                                    << 4
-                                                    << OldUpdatePositionArgs::kOpTimeFieldName
-                                                    << opTime.getTimestamp())))));
-
-    ASSERT_OK(
-        args.initialize(BSON(OldUpdatePositionArgs::kCommandFieldName
-                             << 1
-                             << OldUpdatePositionArgs::kUpdateArrayFieldName
-                             << BSON_ARRAY(BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                << 2
-                                                << OldUpdatePositionArgs::kMemberIdFieldName
-                                                << 1
-                                                << OldUpdatePositionArgs::kOpTimeFieldName
-                                                << opTime.getTimestamp())
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                   << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
-                                                   << 2
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << opTime.getTimestamp())
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                   << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
-                                                   << 3
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << opTime.getTimestamp())
-                                           << BSON(OldUpdatePositionArgs::kConfigVersionFieldName
-                                                   << 2
-                                                   << OldUpdatePositionArgs::kMemberIdFieldName
-                                                   << 4
-                                                   << OldUpdatePositionArgs::kOpTimeFieldName
-                                                   << opTime.getTimestamp())))));
-}
-
-
-TEST_F(ReplCoordTest, OldUpdatePositionArgsReturnsBadValueWhenParsingUpdatePositionArgs) {
-    OldUpdatePositionArgs args;
-    UpdatePositionArgs args2;
-    OpTime opTime = OpTime(Timestamp(100, 1), 0);
-    ASSERT_EQUALS(ErrorCodes::BadValue,
-                  args.initialize(BSON(
-                      UpdatePositionArgs::kCommandFieldName
-                      << 1
-                      << UpdatePositionArgs::kUpdateArrayFieldName
-                      << BSON_ARRAY(BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                         << 2
-                                         << UpdatePositionArgs::kMemberIdFieldName
-                                         << 1
-                                         << UpdatePositionArgs::kDurableOpTimeFieldName
-                                         << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                         << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                         << BSON("ts" << opTime.getTimestamp() << "t" << 3))
-                                    << BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                            << 2
-                                            << UpdatePositionArgs::kMemberIdFieldName
-                                            << 2
-                                            << UpdatePositionArgs::kDurableOpTimeFieldName
-                                            << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                            << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                            << BSON("ts" << opTime.getTimestamp() << "t" << 3))
-                                    << BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                            << 2
-                                            << UpdatePositionArgs::kMemberIdFieldName
-                                            << 3
-                                            << UpdatePositionArgs::kDurableOpTimeFieldName
-                                            << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                            << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                            << BSON("ts" << opTime.getTimestamp() << "t" << 3))
-                                    << BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                            << 2
-                                            << UpdatePositionArgs::kMemberIdFieldName
-                                            << 4
-                                            << UpdatePositionArgs::kDurableOpTimeFieldName
-                                            << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                            << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                            << BSON("ts" << opTime.getTimestamp() << "t" << 3))))));
-    ASSERT_OK(args2.initialize(
-        BSON(UpdatePositionArgs::kCommandFieldName
-             << 1
-             << UpdatePositionArgs::kUpdateArrayFieldName
-             << BSON_ARRAY(BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                << 2
-                                << UpdatePositionArgs::kMemberIdFieldName
-                                << 1
-                                << UpdatePositionArgs::kDurableOpTimeFieldName
-                                << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                << BSON("ts" << opTime.getTimestamp() << "t" << 3))
-                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                   << 2
-                                   << UpdatePositionArgs::kMemberIdFieldName
-                                   << 2
-                                   << UpdatePositionArgs::kDurableOpTimeFieldName
-                                   << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                   << BSON("ts" << opTime.getTimestamp() << "t" << 3))
-                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                   << 2
-                                   << UpdatePositionArgs::kMemberIdFieldName
-                                   << 3
-                                   << UpdatePositionArgs::kDurableOpTimeFieldName
-                                   << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                   << BSON("ts" << opTime.getTimestamp() << "t" << 3))
-                           << BSON(UpdatePositionArgs::kConfigVersionFieldName
-                                   << 2
-                                   << UpdatePositionArgs::kMemberIdFieldName
-                                   << 4
-                                   << UpdatePositionArgs::kDurableOpTimeFieldName
-                                   << BSON("ts" << opTime.getTimestamp() << "t" << 3)
-                                   << UpdatePositionArgs::kAppliedOpTimeFieldName
-                                   << BSON("ts" << opTime.getTimestamp() << "t" << 3))))));
-}
-
 TEST_F(
     ReplCoordTest,
     PopulateUnsetWriteConcernOptionsSyncModeReturnsInputWithSyncModeNoneIfUnsetAndWriteConcernMajorityJournalDefaultIsFalse) {
diff --git a/src/mongo/db/repl/replication_coordinator_mock.cpp b/src/mongo/db/repl/replication_coordinator_mock.cpp
index 41f44d944e7..3ea5c3d7717 100644
--- a/src/mongo/db/repl/replication_coordinator_mock.cpp
+++ b/src/mongo/db/repl/replication_coordinator_mock.cpp
@@ -271,8 +271,7 @@ Status ReplicationCoordinatorMock::resyncData(OperationContext* opCtx, bool wait
     return Status::OK();
 }
 
-StatusWith<BSONObj> ReplicationCoordinatorMock::prepareReplSetUpdatePositionCommand(
-    ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle) const {
+StatusWith<BSONObj> ReplicationCoordinatorMock::prepareReplSetUpdatePositionCommand() const {
     BSONObjBuilder cmdBuilder;
     cmdBuilder.append("replSetUpdatePosition", 1);
     return cmdBuilder.obj();
@@ -362,12 +361,6 @@ Status ReplicationCoordinatorMock::processReplSetElect(const ReplSetElectArgs& a
     return Status::OK();
 }
 
-Status ReplicationCoordinatorMock::processReplSetUpdatePosition(
-    const OldUpdatePositionArgs& updates, long long* configVersion) {
-    // TODO
-    return Status::OK();
-}
-
 Status ReplicationCoordinatorMock::processReplSetUpdatePosition(const UpdatePositionArgs& updates,
                                                                 long long* configVersion) {
     // TODO
diff --git a/src/mongo/db/repl/replication_coordinator_mock.h b/src/mongo/db/repl/replication_coordinator_mock.h
index 42e79009920..8f3e208d90f 100644
--- a/src/mongo/db/repl/replication_coordinator_mock.h
+++ b/src/mongo/db/repl/replication_coordinator_mock.h
@@ -153,8 +153,7 @@ public:
 
     virtual Status resyncData(OperationContext* opCtx, bool waitUntilCompleted) override;
 
-    virtual StatusWith<BSONObj> prepareReplSetUpdatePositionCommand(
-        ReplSetUpdatePositionCommandStyle commandStyle) const override;
+    virtual StatusWith<BSONObj> prepareReplSetUpdatePositionCommand() const override;
 
     virtual Status processReplSetGetStatus(BSONObjBuilder*, ReplSetGetStatusResponseStyle);
 
@@ -199,8 +198,6 @@ public:
 
     virtual Status processReplSetElect(const ReplSetElectArgs& args, BSONObjBuilder* resultObj);
 
-    virtual Status processReplSetUpdatePosition(const OldUpdatePositionArgs& updates,
-                                                long long* configVersion);
     virtual Status processReplSetUpdatePosition(const UpdatePositionArgs& updates,
                                                 long long* configVersion);
 
diff --git a/src/mongo/db/repl/reporter.cpp b/src/mongo/db/repl/reporter.cpp
index b22c180bb7c..b1fe3d50e36 100644
--- a/src/mongo/db/repl/reporter.cpp
+++ b/src/mongo/db/repl/reporter.cpp
@@ -33,7 +33,6 @@
 #include "mongo/db/repl/reporter.h"
 
 #include "mongo/bson/util/bson_extract.h"
-#include "mongo/db/repl/old_update_position_args.h"
 #include "mongo/db/repl/update_position_args.h"
 #include "mongo/rpc/get_status_from_command_result.h"
 #include "mongo/util/assert_util.h"
@@ -68,10 +67,7 @@ long long _parseCommandRequestConfigVersion(const BSONObj& commandRequest) {
  * locally generated update command request object.
  * Returns false if config version is missing in either document.
  */
-bool _isTargetConfigNewerThanRequest(
-    const BSONObj& commandResult,
-    const BSONObj& commandRequest,
-    ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle) {
+bool _isTargetConfigNewerThanRequest(const BSONObj& commandResult, const BSONObj& commandRequest) {
     long long targetConfigVersion;
     if (!bsonExtractIntegerField(commandResult, kConfigVersionFieldName, &targetConfigVersion)
              .isOK()) {
@@ -79,9 +75,7 @@ bool _isTargetConfigNewerThanRequest(
     }
 
     const long long localConfigVersion =
-        commandStyle == ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle
-        ? _parseCommandRequestConfigVersion<UpdatePositionArgs>(commandRequest)
-        : _parseCommandRequestConfigVersion<OldUpdatePositionArgs>(commandRequest);
+        _parseCommandRequestConfigVersion<UpdatePositionArgs>(commandRequest);
     if (localConfigVersion == -1) {
         return false;
     }
@@ -192,19 +186,7 @@ Status Reporter::trigger() {
 }
 
 StatusWith<BSONObj> Reporter::_prepareCommand() {
-    ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle =
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle;
-    {
-        stdx::lock_guard<stdx::mutex> lk(_mutex);
-        invariant(_isActive_inlock());
-        if (!_status.isOK()) {
-            return _status;
-        }
-
-        commandStyle = _commandStyle;
-    }
-
-    auto prepareResult = _prepareReplSetUpdatePositionCommandFn(commandStyle);
+    auto prepareResult = _prepareReplSetUpdatePositionCommandFn();
 
     stdx::lock_guard<stdx::mutex> lk(_mutex);
 
@@ -269,16 +251,8 @@ void Reporter::_processResponseCallback(
 
         // Some error types are OK and should not cause the reporter to stop sending updates to the
         // sync target.
-        if (_status == ErrorCodes::BadValue &&
-            _commandStyle == ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle) {
-            LOG(1) << "Reporter falling back to old style UpdatePosition command for sync source: "
-                   << _target;
-            _status = Status::OK();
-            _commandStyle = ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle;
-            _isWaitingToSendReporter = true;
-        } else if (_status == ErrorCodes::InvalidReplicaSetConfig &&
-                   _isTargetConfigNewerThanRequest(
-                       commandResult, rcbd.request.cmdObj, _commandStyle)) {
+        if (_status == ErrorCodes::InvalidReplicaSetConfig &&
+            _isTargetConfigNewerThanRequest(commandResult, rcbd.request.cmdObj)) {
             LOG(1) << "Reporter found newer configuration on sync source: " << _target
                    << ". Retrying.";
             _status = Status::OK();
diff --git a/src/mongo/db/repl/reporter.h b/src/mongo/db/repl/reporter.h
index cabf6536328..353f3391db6 100644
--- a/src/mongo/db/repl/reporter.h
+++ b/src/mongo/db/repl/reporter.h
@@ -71,8 +71,7 @@ public:
      *
      * The returned status indicates whether or not the command was created.
      */
-    using PrepareReplSetUpdatePositionCommandFn = stdx::function<StatusWith<BSONObj>(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle)>;
+    using PrepareReplSetUpdatePositionCommandFn = stdx::function<StatusWith<BSONObj>()>;
 
     Reporter(executor::TaskExecutor* executor,
              PrepareReplSetUpdatePositionCommandFn prepareReplSetUpdatePositionCommandFn,
@@ -188,10 +187,6 @@ private:
     // Stores the most recent Status returned from the executor.
     Status _status = Status::OK();
 
-    // Stores style of the most recent update command object.
-    ReplicationCoordinator::ReplSetUpdatePositionCommandStyle _commandStyle =
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle;
-
     // _isWaitingToSendReporter is true when Reporter is scheduled to be run by the executor and
     // subsequent updates have come in.
     bool _isWaitingToSendReporter = false;
diff --git a/src/mongo/db/repl/reporter_test.cpp b/src/mongo/db/repl/reporter_test.cpp
index 97485f030e5..aec94c02387 100644
--- a/src/mongo/db/repl/reporter_test.cpp
+++ b/src/mongo/db/repl/reporter_test.cpp
@@ -28,8 +28,6 @@
 
 #include "mongo/platform/basic.h"
 
-#include "mongo/db/repl/old_update_position_args.h"
-#include "mongo/db/repl/optime.h"
 #include "mongo/db/repl/reporter.h"
 #include "mongo/db/repl/update_position_args.h"
 #include "mongo/executor/network_interface_mock.h"
@@ -64,27 +62,17 @@ public:
         _configVersion = configVersion;
     }
 
-    StatusWith<BSONObj> prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle) {
+    StatusWith<BSONObj> prepareReplSetUpdatePositionCommand() {
         BSONObjBuilder cmdBuilder;
         cmdBuilder.append(UpdatePositionArgs::kCommandFieldName, 1);
         BSONArrayBuilder arrayBuilder(
             cmdBuilder.subarrayStart(UpdatePositionArgs::kUpdateArrayFieldName));
         for (auto&& itr : _progressMap) {
             BSONObjBuilder entry(arrayBuilder.subobjStart());
-            switch (commandStyle) {
-                case ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle:
-                    itr.second.lastDurableOpTime.append(
-                        &entry, UpdatePositionArgs::kDurableOpTimeFieldName);
-                    itr.second.lastAppliedOpTime.append(
-                        &entry, UpdatePositionArgs::kAppliedOpTimeFieldName);
-                    break;
-                case ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle:
-                    // Assume protocol version 1.
-                    itr.second.lastDurableOpTime.append(&entry,
-                                                        OldUpdatePositionArgs::kOpTimeFieldName);
-                    break;
-            }
+            itr.second.lastDurableOpTime.append(&entry,
+                                                UpdatePositionArgs::kDurableOpTimeFieldName);
+            itr.second.lastAppliedOpTime.append(&entry,
+                                                UpdatePositionArgs::kAppliedOpTimeFieldName);
             entry.append(UpdatePositionArgs::kMemberIdFieldName, itr.first);
             if (_configVersion != -1) {
                 entry.append(UpdatePositionArgs::kConfigVersionFieldName, _configVersion);
@@ -159,17 +147,13 @@ void ReporterTest::setUp() {
     posUpdater->updateMap(0, OpTime({3, 0}, 1), OpTime({3, 0}, 1));
 
     prepareReplSetUpdatePositionCommandFn =
-        stdx::bind(&MockProgressManager::prepareReplSetUpdatePositionCommand,
-                   posUpdater.get(),
-                   stdx::placeholders::_1);
-
-    reporter = stdx::make_unique<Reporter>(
-        _executorProxy.get(),
-        [this](ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle) {
-            return prepareReplSetUpdatePositionCommandFn(commandStyle);
-        },
-        HostAndPort("h1"),
-        Milliseconds(1000));
+        stdx::bind(&MockProgressManager::prepareReplSetUpdatePositionCommand, posUpdater.get());
+
+    reporter =
+        stdx::make_unique<Reporter>(_executorProxy.get(),
+                                    [this]() { return prepareReplSetUpdatePositionCommandFn(); },
+                                    HostAndPort("h1"),
+                                    Milliseconds(1000));
     launchExecutorThread();
 
     if (triggerAtSetUp()) {
@@ -369,9 +353,8 @@ TEST_F(ReporterTest, InvalidReplicaSetResponseWithSameConfigVersionOnSyncTargetS
     assertReporterDone();
 }
 
-TEST_F(
-    ReporterTest,
-    InvalidReplicaSetResponseWithNewerConfigVersionOnSyncTargetToAnNewCommandStyleRequestDoesNotStopTheReporter) {
+TEST_F(ReporterTest,
+       InvalidReplicaSetResponseWithNewerConfigVersionOnSyncTargetDoesNotStopTheReporter) {
     // Reporter should not retry update command on sync source immediately after seeing newer
     // configuration.
     ASSERT_OK(reporter->trigger());
@@ -386,32 +369,6 @@ TEST_F(
     ASSERT_TRUE(reporter->isActive());
 }
 
-TEST_F(
-    ReporterTest,
-    InvalidReplicaSetResponseWithNewerConfigVersionOnSyncTargetToAnOldCommandStyleRequestDoesNotStopTheReporter) {
-    auto expectedNewStyleCommandRequest = unittest::assertGet(prepareReplSetUpdatePositionCommandFn(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle));
-
-    auto commandRequest =
-        processNetworkResponse(BSON("ok" << 0 << "code" << int(ErrorCodes::BadValue) << "errmsg"
-                                         << "Unexpected field durableOpTime in UpdateInfoArgs"),
-                               true);
-    ASSERT_BSONOBJ_EQ(expectedNewStyleCommandRequest, commandRequest);
-
-    // Update command object should match old style (pre-3.2.4).
-    auto expectedOldStyleCommandRequest = unittest::assertGet(prepareReplSetUpdatePositionCommandFn(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle));
-
-    commandRequest = processNetworkResponse(
-        BSON("ok" << 0 << "code" << int(ErrorCodes::InvalidReplicaSetConfig) << "errmsg"
-                  << "newer config"
-                  << "configVersion"
-                  << posUpdater->getConfigVersion() + 1));
-    ASSERT_BSONOBJ_EQ(expectedOldStyleCommandRequest, commandRequest);
-
-    ASSERT_TRUE(reporter->isActive());
-}
-
 // Schedule while we are already scheduled, it should set "isWaitingToSendReport", then
 // automatically
 // schedule itself after finishing.
@@ -500,9 +457,9 @@ TEST_F(ReporterTest, ShuttingReporterDownWhileSecondCommandRequestIsInProgressSt
 
 TEST_F(ReporterTestNoTriggerAtSetUp, CommandPreparationFailureStopsTheReporter) {
     Status expectedStatus(ErrorCodes::UnknownError, "unknown error");
-    prepareReplSetUpdatePositionCommandFn =
-        [expectedStatus](ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle)
-        -> StatusWith<BSONObj> { return expectedStatus; };
+    prepareReplSetUpdatePositionCommandFn = [expectedStatus]() -> StatusWith<BSONObj> {
+        return expectedStatus;
+    };
     ASSERT_OK(reporter->trigger());
 
     ASSERT_EQUALS(expectedStatus, reporter->join());
@@ -518,9 +475,9 @@ TEST_F(ReporterTest, CommandPreparationFailureDuringRescheduleStopsTheReporter)
 
     // This will cause command preparation to fail for the subsequent request.
     Status expectedStatus(ErrorCodes::UnknownError, "unknown error");
-    prepareReplSetUpdatePositionCommandFn =
-        [expectedStatus](ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle)
-        -> StatusWith<BSONObj> { return expectedStatus; };
+    prepareReplSetUpdatePositionCommandFn = [expectedStatus]() -> StatusWith<BSONObj> {
+        return expectedStatus;
+    };
 
     processNetworkResponse(BSON("ok" << 1));
 
@@ -528,37 +485,6 @@ TEST_F(ReporterTest, CommandPreparationFailureDuringRescheduleStopsTheReporter)
     assertReporterDone();
 }
 
-// If a remote server (most likely running with version before 3.2.4) returns ErrorCodes::BadValue
-// on a new style replSetUpdateCommand command object, we should regenerate the command with
-// pre-3.2.4 style arguments and retry the remote command.
-TEST_F(ReporterTest,
-       BadValueErrorOnNewStyleCommandShouldCauseRescheduleImmediatelyWithOldStyleCommand) {
-    runReadyScheduledTasks();
-
-    auto expectedNewStyleCommandRequest = unittest::assertGet(prepareReplSetUpdatePositionCommandFn(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle));
-
-    auto commandRequest =
-        processNetworkResponse(BSON("ok" << 0 << "code" << int(ErrorCodes::BadValue) << "errmsg"
-                                         << "Unexpected field durableOpTime in UpdateInfoArgs"),
-                               true);
-    ASSERT_BSONOBJ_EQ(expectedNewStyleCommandRequest, commandRequest);
-
-    auto expectedOldStyleCommandRequest = unittest::assertGet(prepareReplSetUpdatePositionCommandFn(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle));
-
-    commandRequest = processNetworkResponse(BSON("ok" << 1));
-
-    // Update command object should match old style (pre-3.2.2).
-    ASSERT_BSONOBJ_NE(expectedNewStyleCommandRequest, expectedOldStyleCommandRequest);
-    ASSERT_BSONOBJ_EQ(expectedOldStyleCommandRequest, commandRequest);
-
-    reporter->shutdown();
-
-    ASSERT_EQUALS(ErrorCodes::CallbackCanceled, reporter->join());
-    assertReporterDone();
-}
-
 TEST_F(ReporterTest, FailedUpdateShouldNotRescheduleUpdate) {
     processNetworkResponse({ErrorCodes::OperationFailed, "update failed", Milliseconds(0)});
 
@@ -678,9 +604,9 @@ TEST_F(ReporterTest, KeepAliveTimeoutFailingToScheduleRemoteCommandShouldMakeRep
     ASSERT_TRUE(reporter->isActive());
 
     Status expectedStatus(ErrorCodes::UnknownError, "failed to prepare update command");
-    prepareReplSetUpdatePositionCommandFn =
-        [expectedStatus](ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle)
-        -> StatusWith<BSONObj> { return expectedStatus; };
+    prepareReplSetUpdatePositionCommandFn = [expectedStatus]() -> StatusWith<BSONObj> {
+        return expectedStatus;
+    };
 
     runUntil(until);
 
diff --git a/src/mongo/db/repl/sync_source_feedback.cpp b/src/mongo/db/repl/sync_source_feedback.cpp
index 8fd1e66d6a5..4bd190ff14e 100644
--- a/src/mongo/db/repl/sync_source_feedback.cpp
+++ b/src/mongo/db/repl/sync_source_feedback.cpp
@@ -61,8 +61,7 @@ Milliseconds calculateKeepAliveInterval(const ReplSetConfig& rsConfig) {
  */
 Reporter::PrepareReplSetUpdatePositionCommandFn makePrepareReplSetUpdatePositionCommandFn(
     ReplicationCoordinator* replCoord, const HostAndPort& syncTarget, BackgroundSync* bgsync) {
-    return [syncTarget, replCoord, bgsync](ReplicationCoordinator::ReplSetUpdatePositionCommandStyle
-                                               commandStyle) -> StatusWith<BSONObj> {
+    return [syncTarget, replCoord, bgsync]() -> StatusWith<BSONObj> {
         auto currentSyncTarget = bgsync->getSyncTarget();
         if (currentSyncTarget != syncTarget) {
             if (currentSyncTarget.empty()) {
@@ -84,7 +83,7 @@ Reporter::PrepareReplSetUpdatePositionCommandFn makePrepareReplSetUpdatePosition
                           "Currently primary - no one to send updates to");
         }
 
-        return replCoord->prepareReplSetUpdatePositionCommand(commandStyle);
+        return replCoord->prepareReplSetUpdatePositionCommand();
     };
 }
 
diff --git a/src/mongo/db/repl/topology_coordinator.cpp b/src/mongo/db/repl/topology_coordinator.cpp
index 3607128a2c2..29cce45feca 100644
--- a/src/mongo/db/repl/topology_coordinator.cpp
+++ b/src/mongo/db/repl/topology_coordinator.cpp
@@ -2049,7 +2049,6 @@ void TopologyCoordinator::prepareStatusResponse(const ReplSetStatusArgs& rsStatu
 }
 
 StatusWith<BSONObj> TopologyCoordinator::prepareReplSetUpdatePositionCommand(
-    ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle,
     OpTime currentCommittedSnapshotOpTime) const {
     BSONObjBuilder cmdBuilder;
     invariant(_rsConfig.isInitialized());
@@ -2072,33 +2071,19 @@ StatusWith<BSONObj> TopologyCoordinator::prepareReplSetUpdatePositionCommand(
         }
 
         BSONObjBuilder entry(arrayBuilder.subobjStart());
-        switch (commandStyle) {
-            case ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle:
-                memberData.getLastDurableOpTime().append(
-                    &entry, UpdatePositionArgs::kDurableOpTimeFieldName);
-                memberData.getLastAppliedOpTime().append(
-                    &entry, UpdatePositionArgs::kAppliedOpTimeFieldName);
-                break;
-            case ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kOldStyle:
-                entry.append("_id", memberData.getRid());
-                if (_rsConfig.getProtocolVersion() == 1) {
-                    memberData.getLastDurableOpTime().append(&entry, "optime");
-                } else {
-                    entry.append("optime", memberData.getLastDurableOpTime().getTimestamp());
-                }
-                break;
-        }
+        memberData.getLastDurableOpTime().append(&entry,
+                                                 UpdatePositionArgs::kDurableOpTimeFieldName);
+        memberData.getLastAppliedOpTime().append(&entry,
+                                                 UpdatePositionArgs::kAppliedOpTimeFieldName);
         entry.append(UpdatePositionArgs::kMemberIdFieldName, memberData.getMemberId());
         entry.append(UpdatePositionArgs::kConfigVersionFieldName, _rsConfig.getConfigVersion());
     }
     arrayBuilder.done();
 
-    // Add metadata to command. Old style parsing logic will reject the metadata.
-    if (commandStyle == ReplicationCoordinator::ReplSetUpdatePositionCommandStyle::kNewStyle) {
-        prepareReplSetMetadata(currentCommittedSnapshotOpTime)
-            .writeToMetadata(&cmdBuilder)
-            .transitional_ignore();
-    }
+    // Add metadata to command
+    prepareReplSetMetadata(currentCommittedSnapshotOpTime)
+        .writeToMetadata(&cmdBuilder)
+        .transitional_ignore();
     return cmdBuilder.obj();
 }
 
diff --git a/src/mongo/db/repl/topology_coordinator.h b/src/mongo/db/repl/topology_coordinator.h
index 34ca9906d05..44f5abcead0 100644
--- a/src/mongo/db/repl/topology_coordinator.h
+++ b/src/mongo/db/repl/topology_coordinator.h
@@ -360,7 +360,6 @@ public:
 
     // Produce a replSetUpdatePosition command to be sent to the node's sync source.
     StatusWith<BSONObj> prepareReplSetUpdatePositionCommand(
-        ReplicationCoordinator::ReplSetUpdatePositionCommandStyle commandStyle,
         OpTime currentCommittedSnapshotOpTime) const;
 
     // produce a reply to an ismaster request.  It is only valid to call this if we are a