SERVER-19905 consistently use t as the field name for the term portion of an OpTime

28 files changed, 143 insertions, 164 deletions

diff --git a/jstests/core/read_after_optime.js b/jstests/core/read_after_optime.js
index f67692d955e..4f8d601facf 100644
--- a/jstests/core/read_after_optime.js
+++ b/jstests/core/read_after_optime.js
@@ -11,7 +11,7 @@ var res = assert.commandFailed(db.runCommand({
     find: 'user',
     filter: { x: 1 },
     readConcern: {
-        afterOpTime: { ts: futureOpTime, term: 0 }
+        afterOpTime: { ts: futureOpTime, t: 0 }
     }
 }));
 
diff --git a/jstests/replsets/read_after_optime.js b/jstests/replsets/read_after_optime.js
index fc8407d8566..cb19940ee05 100644
--- a/jstests/replsets/read_after_optime.js
+++ b/jstests/replsets/read_after_optime.js
@@ -22,7 +22,7 @@ var runTest = function(testDB, primaryConn) {
         find: 'user',
         filter: { x: 1 },
         readConcern: {
-            afterOpTime: { ts: twoSecTS, term: 0 }
+            afterOpTime: { ts: twoSecTS, t: 0 }
         },
         maxTimeMS: 1000
     }));
@@ -40,7 +40,7 @@ var runTest = function(testDB, primaryConn) {
         find: 'user',
         filter: { x: 1 },
         readConcern: {
-            afterOpTime: { ts: twoSecTS, term: 0 },
+            afterOpTime: { ts: twoSecTS, t: 0 },
             maxTimeMS: 10 * 1000
         }
     }));
diff --git a/src/mongo/bson/util/bson_extract.cpp b/src/mongo/bson/util/bson_extract.cpp
index 4906d0897a5..54d1e1f47ae 100644
--- a/src/mongo/bson/util/bson_extract.cpp
+++ b/src/mongo/bson/util/bson_extract.cpp
@@ -32,13 +32,6 @@
 
 namespace mongo {
 
-namespace {
-
-const char kTermFieldName[] = "term";
-const char kTimestampFieldName[] = "ts";
-
-}  // namespace
-
 Status bsonExtractField(const BSONObj& object, StringData fieldName, BSONElement* outElement) {
     BSONElement element = object.getField(fieldName);
     if (element.eoo())
@@ -113,11 +106,11 @@ Status bsonExtractOpTimeField(const BSONObj& object, StringData fieldName, repl:
 
     BSONObj opTimeObj = element.Obj();
     Timestamp ts;
-    status = bsonExtractTimestampField(opTimeObj, kTimestampFieldName, &ts);
+    status = bsonExtractTimestampField(opTimeObj, repl::OpTime::kTimestampFieldName, &ts);
     if (!status.isOK())
         return status;
     long long term;
-    status = bsonExtractIntegerField(opTimeObj, kTermFieldName, &term);
+    status = bsonExtractIntegerField(opTimeObj, repl::OpTime::kTermFieldName, &term);
     if (!status.isOK())
         return status;
     *out = repl::OpTime(ts, term);
diff --git a/src/mongo/bson/util/bson_extract_test.cpp b/src/mongo/bson/util/bson_extract_test.cpp
index 1c7261d1301..95951efb87e 100644
--- a/src/mongo/bson/util/bson_extract_test.cpp
+++ b/src/mongo/bson/util/bson_extract_test.cpp
@@ -86,7 +86,7 @@ TEST(ExtractBSON, ExtractStringFieldWithDefault) {
 
 TEST(ExtractBSON, ExtractOpTimeField) {
     // Outer object cases.
-    BSONObj obj = BSON("a" << BSON("ts" << Timestamp(10, 0) << "term" << 2) << "b"
+    BSONObj obj = BSON("a" << BSON("ts" << Timestamp(10, 0) << "t" << 2) << "b"
                            << "notAnObj");
     repl::OpTime opTime;
     ASSERT_OK(bsonExtractOpTimeField(obj, "a", &opTime));
@@ -97,13 +97,13 @@ TEST(ExtractBSON, ExtractOpTimeField) {
     // Missing timestamp field.
     obj = BSON("a" << BSON("ts"
                            << "notATimestamp"
-                           << "term" << 2));
+                           << "t" << 2));
     ASSERT_EQUALS(ErrorCodes::TypeMismatch, bsonExtractOpTimeField(obj, "a", &opTime));
     // Wrong typed timestamp field.
-    obj = BSON("a" << BSON("term" << 2));
+    obj = BSON("a" << BSON("t" << 2));
     ASSERT_EQUALS(ErrorCodes::NoSuchKey, bsonExtractOpTimeField(obj, "a", &opTime));
     // Missing term field.
-    obj = BSON("a" << BSON("ts" << Timestamp(10, 0) << "term"
+    obj = BSON("a" << BSON("ts" << Timestamp(10, 0) << "t"
                                 << "notANumber"));
     ASSERT_EQUALS(ErrorCodes::TypeMismatch, bsonExtractOpTimeField(obj, "a", &opTime));
     // Wrong typed term field.
diff --git a/src/mongo/db/repl/bgsync.cpp b/src/mongo/db/repl/bgsync.cpp
index 7a8c76ffb4a..40afe9f7356 100644
--- a/src/mongo/db/repl/bgsync.cpp
+++ b/src/mongo/db/repl/bgsync.cpp
@@ -101,7 +101,7 @@ Status checkRemoteOplogStart(stdx::function<StatusWith<BSONObj>()> getNextOperat
                       "we are ahead of the sync source, will try to roll back");
     }
     BSONObj o = result.getValue();
-    OpTime opTime = fassertStatusOK(28778, OpTime::parseFromBSON(o));
+    OpTime opTime = fassertStatusOK(28778, OpTime::parseFromOplogEntry(o));
     long long hash = o["h"].numberLong();
     if (opTime != lastOpTimeFetched || hash != lastHashFetched) {
         return Status(ErrorCodes::OplogStartMissing,
@@ -509,7 +509,7 @@ void BackgroundSync::_fetcherCallback(const StatusWith<Fetcher::QueryResponse>&
         {
             stdx::unique_lock<stdx::mutex> lock(_mutex);
             _lastFetchedHash = o["h"].numberLong();
-            _lastOpTimeFetched = fassertStatusOK(28770, OpTime::parseFromBSON(o));
+            _lastOpTimeFetched = fassertStatusOK(28770, OpTime::parseFromOplogEntry(o));
             LOG(3) << "lastOpTimeFetched: " << _lastOpTimeFetched;
         }
     }
diff --git a/src/mongo/db/repl/minvalid.cpp b/src/mongo/db/repl/minvalid.cpp
index 5584ea54658..7860d4ac988 100644
--- a/src/mongo/db/repl/minvalid.cpp
+++ b/src/mongo/db/repl/minvalid.cpp
@@ -111,7 +111,7 @@ OpTime getMinValid(OperationContext* txn) {
         BSONObj mv;
         bool found = Helpers::getSingleton(txn, minvalidNS, mv);
         if (found) {
-            return fassertStatusOK(28771, OpTime::parseFromBSON(mv));
+            return fassertStatusOK(28771, OpTime::parseFromOplogEntry(mv));
         }
         return OpTime();
     }
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index b7c3ca23416..99e3dcf0d14 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -314,7 +314,10 @@ void _logOp(OperationContext* txn,
 
     BSONObjBuilder b(256);
 
-    slot.first.append(&b);
+    b.append("ts", slot.first.getTimestamp());
+    if (slot.first.getTerm() != -1) {
+        b.append("t", slot.first.getTerm());
+    }
     b.append("h", slot.second);
     b.append("v", OPLOG_VERSION);
     b.append("op", opstr);
@@ -385,7 +388,7 @@ OpTime writeOpsToOplog(OperationContext* txn, const std::deque<BSONObj>& ops) {
         checkOplogInsert(
             _localOplogCollection->insertDocuments(txn, opsVect.begin(), opsVect.end(), false));
         lastOptime =
-            fassertStatusOK(ErrorCodes::InvalidBSON, OpTime::parseFromBSON(opsVect.back()));
+            fassertStatusOK(ErrorCodes::InvalidBSON, OpTime::parseFromOplogEntry(opsVect.back()));
         wunit.commit();
     }
     MONGO_WRITE_CONFLICT_RETRY_LOOP_END(txn, "writeOps", _localOplogCollection->ns().ns());
@@ -896,7 +899,7 @@ void initTimestampFromOplog(OperationContext* txn, const std::string& oplogNS) {
 
     if (!lastOp.isEmpty()) {
         LOG(1) << "replSet setting last Timestamp";
-        const OpTime opTime = fassertStatusOK(28696, OpTime::parseFromBSON(lastOp));
+        const OpTime opTime = fassertStatusOK(28696, OpTime::parseFromOplogEntry(lastOp));
         setNewTimestamp(opTime.getTimestamp());
     }
 }
@@ -996,7 +999,7 @@ void SnapshotThread::run() {
                     continue;  // oplog is completely empty.
 
                 const auto op = record->data.releaseToBson();
-                opTimeOfSnapshot = fassertStatusOK(28780, OpTime::parseFromBSON(op));
+                opTimeOfSnapshot = fassertStatusOK(28780, OpTime::parseFromOplogEntry(op));
                 invariant(!opTimeOfSnapshot.isNull());
             }
 
diff --git a/src/mongo/db/repl/oplogreader.cpp b/src/mongo/db/repl/oplogreader.cpp
index 1332e6f7542..ecda101a91f 100644
--- a/src/mongo/db/repl/oplogreader.cpp
+++ b/src/mongo/db/repl/oplogreader.cpp
@@ -183,7 +183,8 @@ void OplogReader::connectToSyncSource(OperationContext* txn,
         // Read the first (oldest) op and confirm that it's not newer than our last
         // fetched op. Otherwise, we have fallen off the back of that source's oplog.
         BSONObj remoteOldestOp(findOne(rsOplogName.c_str(), Query()));
-        OpTime remoteOldOpTime = fassertStatusOK(28776, OpTime::parseFromBSON(remoteOldestOp));
+        OpTime remoteOldOpTime =
+            fassertStatusOK(28776, OpTime::parseFromOplogEntry(remoteOldestOp));
 
         // remoteOldOpTime may come from a very old config, so we cannot compare their terms.
         if (!lastOpTimeFetched.isNull() &&
diff --git a/src/mongo/db/repl/optime.cpp b/src/mongo/db/repl/optime.cpp
index 172302b42c1..92a3c5556ca 100644
--- a/src/mongo/db/repl/optime.cpp
+++ b/src/mongo/db/repl/optime.cpp
@@ -37,12 +37,9 @@
 
 namespace mongo {
 namespace repl {
-namespace {
 
-const char* kTimestampFieldName = "ts";
-const char* kTermFieldName = "t";
-
-}  // namespace
+const char OpTime::kTimestampFieldName[] = "ts";
+const char OpTime::kTermFieldName[] = "t";
 
 OpTime::OpTime(Timestamp ts, long long term) : _timestamp(std::move(ts)), _term(term) {}
 
@@ -62,16 +59,15 @@ bool OpTime::isNull() const {
     return _timestamp.isNull();
 }
 
-void OpTime::append(BSONObjBuilder* builder) const {
-    builder->append(kTimestampFieldName, _timestamp);
+void OpTime::append(BSONObjBuilder* builder, const std::string& subObjName) const {
+    BSONObjBuilder opTimeBuilder(builder->subobjStart(subObjName));
+    opTimeBuilder.append(kTimestampFieldName, _timestamp);
 
-    // Don't add term in protocol version 0.
-    if (_term != kUninitializedTerm) {
-        builder->append(kTermFieldName, _term);
-    }
+    opTimeBuilder.append(kTermFieldName, _term);
+    opTimeBuilder.doneFast();
 }
 
-StatusWith<OpTime> OpTime::parseFromBSON(const BSONObj& obj) {
+StatusWith<OpTime> OpTime::parseFromOplogEntry(const BSONObj& obj) {
     Timestamp ts;
     Status status = bsonExtractTimestampField(obj, kTimestampFieldName, &ts);
     if (!status.isOK())
diff --git a/src/mongo/db/repl/optime.h b/src/mongo/db/repl/optime.h
index c530ca51f97..0af26bc8250 100644
--- a/src/mongo/db/repl/optime.h
+++ b/src/mongo/db/repl/optime.h
@@ -49,6 +49,9 @@ namespace repl {
 
 class OpTime {
 public:
+    static const char kTimestampFieldName[];
+    static const char kTermFieldName[];
+
     // The term of an OpTime generated by old protocol version.
     static const long long kUninitializedTerm = -1;
 
@@ -70,11 +73,11 @@ public:
 
     /**
      * Serializes the contents of this optime to the specified builder in the form:
-     *      { ts: <timestamp>, t: term }
+     *      subObjName : { ts: <timestamp>, t: <term> }
      */
-    void append(BSONObjBuilder* builder) const;
+    void append(BSONObjBuilder* builder, const std::string& subObjName) const;
 
-    static StatusWith<OpTime> parseFromBSON(const BSONObj& obj);
+    static StatusWith<OpTime> parseFromOplogEntry(const BSONObj& obj);
 
     std::string toString() const;
 
diff --git a/src/mongo/db/repl/read_concern_args.cpp b/src/mongo/db/repl/read_concern_args.cpp
index 42c7dab7361..1389a7380a1 100644
--- a/src/mongo/db/repl/read_concern_args.cpp
+++ b/src/mongo/db/repl/read_concern_args.cpp
@@ -50,9 +50,7 @@ const char kLinearizableReadConcernStr[] = "linearizable";
 }  // unnamed namespace
 
 const string ReadConcernArgs::kReadConcernFieldName("readConcern");
-const string ReadConcernArgs::kOpTimeFieldName("afterOpTime");
-const string ReadConcernArgs::kOpTimestampFieldName("ts");
-const string ReadConcernArgs::kOpTermFieldName("term");
+const string ReadConcernArgs::kAfterOpTimeFieldName("afterOpTime");
 const string ReadConcernArgs::kLevelFieldName("level");
 
 ReadConcernArgs::ReadConcernArgs() = default;
@@ -83,9 +81,9 @@ Status ReadConcernArgs::initialize(const BSONObj& cmdObj) {
 
     BSONObj readConcernObj = readConcernElem.Obj();
 
-    if (readConcernObj.hasField(kOpTimeFieldName)) {
+    if (readConcernObj.hasField(kAfterOpTimeFieldName)) {
         OpTime opTime;
-        auto opTimeStatus = bsonExtractOpTimeField(readConcernObj, kOpTimeFieldName, &opTime);
+        auto opTimeStatus = bsonExtractOpTimeField(readConcernObj, kAfterOpTimeFieldName, &opTime);
         if (!opTimeStatus.isOK()) {
             return opTimeStatus;
         }
@@ -138,10 +136,7 @@ void ReadConcernArgs::appendInfo(BSONObjBuilder* builder) {
     }
 
     if (_opTime) {
-        BSONObjBuilder afterBuilder(rcBuilder.subobjStart(kOpTimeFieldName));
-        afterBuilder.append(kOpTimestampFieldName, _opTime->getTimestamp());
-        afterBuilder.append(kOpTermFieldName, _opTime->getTerm());
-        afterBuilder.done();
+        _opTime->append(&rcBuilder, kAfterOpTimeFieldName);
     }
 
     rcBuilder.done();
diff --git a/src/mongo/db/repl/read_concern_args.h b/src/mongo/db/repl/read_concern_args.h
index c6f3605a9fb..a010d9c8793 100644
--- a/src/mongo/db/repl/read_concern_args.h
+++ b/src/mongo/db/repl/read_concern_args.h
@@ -46,9 +46,7 @@ enum class ReadConcernLevel { kLocalReadConcern, kMajorityReadConcern, kLineariz
 class ReadConcernArgs {
 public:
     static const std::string kReadConcernFieldName;
-    static const std::string kOpTermFieldName;
-    static const std::string kOpTimeFieldName;
-    static const std::string kOpTimestampFieldName;
+    static const std::string kAfterOpTimeFieldName;
     static const std::string kLevelFieldName;
 
     ReadConcernArgs();
diff --git a/src/mongo/db/repl/read_concern_args_test.cpp b/src/mongo/db/repl/read_concern_args_test.cpp
index 96077da684c..34fa0d41037 100644
--- a/src/mongo/db/repl/read_concern_args_test.cpp
+++ b/src/mongo/db/repl/read_concern_args_test.cpp
@@ -36,12 +36,12 @@ namespace {
 
 TEST(ReadAfterParse, ReadAfterOnly) {
     ReadConcernArgs readAfterOpTime;
-    ASSERT_OK(readAfterOpTime.initialize(
-        BSON("find"
-             << "test" << ReadConcernArgs::kReadConcernFieldName
-             << BSON(ReadConcernArgs::kOpTimeFieldName
-                     << BSON(ReadConcernArgs::kOpTimestampFieldName
-                             << Timestamp(20, 30) << ReadConcernArgs::kOpTermFieldName << 2)))));
+    ASSERT_OK(readAfterOpTime.initialize(BSON("find"
+                                              << "test" << ReadConcernArgs::kReadConcernFieldName
+                                              << BSON(ReadConcernArgs::kAfterOpTimeFieldName
+                                                      << BSON(OpTime::kTimestampFieldName
+                                                              << Timestamp(20, 30)
+                                                              << OpTime::kTermFieldName << 2)))));
 
     ASSERT_EQ(Timestamp(20, 30), readAfterOpTime.getOpTime().getTimestamp());
     ASSERT_EQ(2, readAfterOpTime.getOpTime().getTerm());
@@ -64,9 +64,9 @@ TEST(ReadAfterParse, ReadCommittedFullSpecification) {
     ASSERT_OK(readAfterOpTime.initialize(
         BSON("find"
              << "test" << ReadConcernArgs::kReadConcernFieldName
-             << BSON(ReadConcernArgs::kOpTimeFieldName
-                     << BSON(ReadConcernArgs::kOpTimestampFieldName
-                             << Timestamp(20, 30) << ReadConcernArgs::kOpTermFieldName << 2)
+             << BSON(ReadConcernArgs::kAfterOpTimeFieldName
+                     << BSON(OpTime::kTimestampFieldName << Timestamp(20, 30)
+                                                         << OpTime::kTermFieldName << 2)
                      << ReadConcernArgs::kLevelFieldName << "majority"))));
 
     ASSERT_EQ(Timestamp(20, 30), readAfterOpTime.getOpTime().getTimestamp());
@@ -96,7 +96,7 @@ TEST(ReadAfterParse, BadOpTimeType) {
     ASSERT_NOT_OK(
         readAfterOpTime.initialize(BSON("find"
                                         << "test" << ReadConcernArgs::kReadConcernFieldName
-                                        << BSON(ReadConcernArgs::kOpTimeFieldName << 2))));
+                                        << BSON(ReadConcernArgs::kAfterOpTimeFieldName << 2))));
 }
 
 TEST(ReadAfterParse, OpTimeNotNeededForValidReadConcern) {
@@ -111,9 +111,8 @@ TEST(ReadAfterParse, NoOpTimeTS) {
     ASSERT_NOT_OK(
         readAfterOpTime.initialize(BSON("find"
                                         << "test" << ReadConcernArgs::kReadConcernFieldName
-                                        << BSON(ReadConcernArgs::kOpTimeFieldName
-                                                << BSON(ReadConcernArgs::kOpTimestampFieldName
-                                                        << 2)))));
+                                        << BSON(ReadConcernArgs::kAfterOpTimeFieldName
+                                                << BSON(OpTime::kTimestampFieldName << 2)))));
 }
 
 TEST(ReadAfterParse, NoOpTimeTerm) {
@@ -121,28 +120,30 @@ TEST(ReadAfterParse, NoOpTimeTerm) {
     ASSERT_NOT_OK(
         readAfterOpTime.initialize(BSON("find"
                                         << "test" << ReadConcernArgs::kReadConcernFieldName
-                                        << BSON(ReadConcernArgs::kOpTimeFieldName
-                                                << BSON(ReadConcernArgs::kOpTermFieldName << 2)))));
+                                        << BSON(ReadConcernArgs::kAfterOpTimeFieldName
+                                                << BSON(OpTime::kTermFieldName << 2)))));
 }
 
 TEST(ReadAfterParse, BadOpTimeTSType) {
     ReadConcernArgs readAfterOpTime;
-    ASSERT_NOT_OK(readAfterOpTime.initialize(
-        BSON("find"
-             << "test" << ReadConcernArgs::kReadConcernFieldName
-             << BSON(ReadConcernArgs::kOpTimeFieldName
-                     << BSON(ReadConcernArgs::kOpTimestampFieldName
-                             << BSON("x" << 1) << ReadConcernArgs::kOpTermFieldName << 2)))));
+    ASSERT_NOT_OK(
+        readAfterOpTime.initialize(BSON("find"
+                                        << "test" << ReadConcernArgs::kReadConcernFieldName
+                                        << BSON(ReadConcernArgs::kAfterOpTimeFieldName
+                                                << BSON(OpTime::kTimestampFieldName
+                                                        << BSON("x" << 1) << OpTime::kTermFieldName
+                                                        << 2)))));
 }
 
 TEST(ReadAfterParse, BadOpTimeTermType) {
     ReadConcernArgs readAfterOpTime;
-    ASSERT_NOT_OK(readAfterOpTime.initialize(
-        BSON("find"
-             << "test" << ReadConcernArgs::kReadConcernFieldName
-             << BSON(ReadConcernArgs::kOpTimeFieldName
-                     << BSON(ReadConcernArgs::kOpTimestampFieldName
-                             << Timestamp(1, 0) << ReadConcernArgs::kOpTermFieldName << "y")))));
+    ASSERT_NOT_OK(
+        readAfterOpTime.initialize(BSON("find"
+                                        << "test" << ReadConcernArgs::kReadConcernFieldName
+                                        << BSON(ReadConcernArgs::kAfterOpTimeFieldName
+                                                << BSON(OpTime::kTimestampFieldName
+                                                        << Timestamp(1, 0) << OpTime::kTermFieldName
+                                                        << "y")))));
 }
 
 TEST(ReadAfterParse, BadLevelType) {
@@ -177,11 +178,10 @@ TEST(ReadAfterSerialize, ReadAfterOnly) {
     ReadConcernArgs readAfterOpTime(OpTime(Timestamp(20, 30), 2), boost::none);
     readAfterOpTime.appendInfo(&builder);
 
-    BSONObj expectedObj(
-        BSON(ReadConcernArgs::kReadConcernFieldName
-             << BSON(ReadConcernArgs::kOpTimeFieldName
-                     << BSON(ReadConcernArgs::kOpTimestampFieldName
-                             << Timestamp(20, 30) << ReadConcernArgs::kOpTermFieldName << 2))));
+    BSONObj expectedObj(BSON(ReadConcernArgs::kReadConcernFieldName
+                             << BSON(ReadConcernArgs::kAfterOpTimeFieldName << BSON(
+                                         OpTime::kTimestampFieldName
+                                         << Timestamp(20, 30) << OpTime::kTermFieldName << 2))));
 
     ASSERT_EQ(expectedObj, builder.done());
 }
@@ -203,12 +203,11 @@ TEST(ReadAfterSerialize, FullSpecification) {
                                     ReadConcernLevel::kMajorityReadConcern);
     readAfterOpTime.appendInfo(&builder);
 
-    BSONObj expectedObj(
-        BSON(ReadConcernArgs::kReadConcernFieldName
-             << BSON(ReadConcernArgs::kLevelFieldName
-                     << "majority" << ReadConcernArgs::kOpTimeFieldName
-                     << BSON(ReadConcernArgs::kOpTimestampFieldName
-                             << Timestamp(20, 30) << ReadConcernArgs::kOpTermFieldName << 2))));
+    BSONObj expectedObj(BSON(ReadConcernArgs::kReadConcernFieldName << BSON(
+                                 ReadConcernArgs::kLevelFieldName
+                                 << "majority" << ReadConcernArgs::kAfterOpTimeFieldName
+                                 << BSON(OpTime::kTimestampFieldName
+                                         << Timestamp(20, 30) << OpTime::kTermFieldName << 2))));
 
     ASSERT_EQ(expectedObj, builder.done());
 }
diff --git a/src/mongo/db/repl/repl_set_heartbeat_response.cpp b/src/mongo/db/repl/repl_set_heartbeat_response.cpp
index 1acccd49d03..bb3d4918c02 100644
--- a/src/mongo/db/repl/repl_set_heartbeat_response.cpp
+++ b/src/mongo/db/repl/repl_set_heartbeat_response.cpp
@@ -119,10 +119,7 @@ void ReplSetHeartbeatResponse::addToBSON(BSONObjBuilder* builder, bool isProtoco
     }
     if (_opTimeSet) {
         if (isProtocolVersionV1) {
-            BSONObjBuilder opTime(builder->subobjStart(kOpTimeFieldName));
-            opTime.append(kTimestampFieldName, _opTime.getTimestamp());
-            opTime.append(kTermFieldName, _opTime.getTerm());
-            opTime.done();
+            _opTime.append(builder, kOpTimeFieldName);
         } else {
             builder->appendDate(kOpTimeFieldName,
                                 Date_t::fromMillisSinceEpoch(_opTime.getTimestamp().asLL()));
diff --git a/src/mongo/db/repl/repl_set_request_votes_args.cpp b/src/mongo/db/repl/repl_set_request_votes_args.cpp
index 51a049131a2..9001272d94b 100644
--- a/src/mongo/db/repl/repl_set_request_votes_args.cpp
+++ b/src/mongo/db/repl/repl_set_request_votes_args.cpp
@@ -42,7 +42,6 @@ const std::string kConfigVersionFieldName = "configVersion";
 const std::string kDryRunFieldName = "dryRun";
 const std::string kLastCommittedOpFieldName = "lastCommittedOp";
 const std::string kOkFieldName = "ok";
-const std::string kOpTimeFieldName = "ts";
 const std::string kReasonFieldName = "reason";
 const std::string kSetNameFieldName = "setName";
 const std::string kTermFieldName = "term";
@@ -54,7 +53,6 @@ const std::string kLegalArgsFieldNames[] = {
     kConfigVersionFieldName,
     kDryRunFieldName,
     kLastCommittedOpFieldName,
-    kOpTimeFieldName,
     kSetNameFieldName,
     kTermFieldName,
 };
@@ -129,10 +127,7 @@ void ReplSetRequestVotesArgs::addToBSON(BSONObjBuilder* builder) const {
     builder->append(kTermFieldName, _term);
     builder->appendIntOrLL(kCandidateIdFieldName, _candidateId);
     builder->appendIntOrLL(kConfigVersionFieldName, _cfgver);
-    BSONObjBuilder lastCommittedOp(builder->subobjStart(kLastCommittedOpFieldName));
-    lastCommittedOp.append(kOpTimeFieldName, _lastCommittedOp.getTimestamp());
-    lastCommittedOp.append(kTermFieldName, _lastCommittedOp.getTerm());
-    lastCommittedOp.done();
+    _lastCommittedOp.append(builder, kLastCommittedOpFieldName);
 }
 
 Status ReplSetRequestVotesResponse::initialize(const BSONObj& argsObj) {
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index c78b129ba39..215e6d96e0a 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -307,7 +307,7 @@ StatusWith<OpTime> ReplicationCoordinatorExternalStateImpl::loadLastOpTime(Opera
                                                     << " entry to have type Timestamp, but found "
                                                     << typeName(tsElement.type()));
         }
-        return OpTime::parseFromBSON(oplogEntry);
+        return OpTime::parseFromOplogEntry(oplogEntry);
     } catch (const DBException& ex) {
         return StatusWith<OpTime>(ex.toStatus());
     }
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index a101e2b9aa1..291b591ab3f 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -1507,8 +1507,7 @@ bool ReplicationCoordinatorImpl::prepareReplSetUpdatePositionCommand(BSONObjBuil
         BSONObjBuilder entry(arrayBuilder.subobjStart());
         entry.append("_id", itr->rid);
         if (isV1ElectionProtocol()) {
-            BSONObjBuilder opTimeBuilder(entry.subobjStart("optime"));
-            itr->opTime.append(&opTimeBuilder);
+            itr->opTime.append(&entry, "optime");
         } else {
             entry.append("optime", itr->opTime.getTimestamp());
         }
diff --git a/src/mongo/db/repl/replication_coordinator_impl_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
index 7f71262204f..ff49082a3e6 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
@@ -35,6 +35,7 @@
 #include <set>
 #include <vector>
 
+#include "mongo/bson/util/bson_extract.h"
 #include "mongo/db/operation_context_noop.h"
 #include "mongo/db/repl/handshake_args.h"
 #include "mongo/db/repl/is_master_response.h"
@@ -2501,19 +2502,19 @@ TEST_F(ReplCoordTest, MetadataWrongConfigVersion) {
 
     // lower configVersion
     StatusWith<rpc::ReplSetMetadata> metadata = rpc::ReplSetMetadata::readFromMetadata(BSON(
-        rpc::kReplSetMetadataFieldName << BSON(
-            "lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "term" << 2) << "lastOpVisible"
-                              << BSON("ts" << Timestamp(10, 0) << "term" << 2) << "configVersion"
-                              << 1 << "primaryIndex" << 2 << "term" << 2)));
+        rpc::kReplSetMetadataFieldName
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "t" << 2) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(10, 0) << "t" << 2) << "configVersion"
+                                  << 1 << "primaryIndex" << 2 << "term" << 2)));
     getReplCoord()->processReplSetMetadata(metadata.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(0, 0), 0), getReplCoord()->getLastCommittedOpTime());
 
     // higher configVersion
     StatusWith<rpc::ReplSetMetadata> metadata2 = rpc::ReplSetMetadata::readFromMetadata(BSON(
-        rpc::kReplSetMetadataFieldName << BSON(
-            "lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "term" << 2) << "lastOpVisible"
-                              << BSON("ts" << Timestamp(10, 0) << "term" << 2) << "configVersion"
-                              << 100 << "primaryIndex" << 2 << "term" << 2)));
+        rpc::kReplSetMetadataFieldName
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "t" << 2) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(10, 0) << "t" << 2) << "configVersion"
+                                  << 100 << "primaryIndex" << 2 << "term" << 2)));
     getReplCoord()->processReplSetMetadata(metadata2.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(0, 0), 0), getReplCoord()->getLastCommittedOpTime());
 }
@@ -2544,10 +2545,10 @@ TEST_F(ReplCoordTest, MetadataUpdatesLastCommittedOpTime) {
 
     // higher OpTime, should change
     StatusWith<rpc::ReplSetMetadata> metadata = rpc::ReplSetMetadata::readFromMetadata(BSON(
-        rpc::kReplSetMetadataFieldName << BSON(
-            "lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "term" << 1) << "lastOpVisible"
-                              << BSON("ts" << Timestamp(10, 0) << "term" << 1) << "configVersion"
-                              << 2 << "primaryIndex" << 2 << "term" << 1)));
+        rpc::kReplSetMetadataFieldName
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "t" << 1) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(10, 0) << "t" << 1) << "configVersion"
+                                  << 2 << "primaryIndex" << 2 << "term" << 1)));
     getReplCoord()->processReplSetMetadata(metadata.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(10, 0), 1), getReplCoord()->getLastCommittedOpTime());
     ASSERT_EQUALS(OpTime(Timestamp(10, 0), 1), getReplCoord()->getCurrentCommittedSnapshotOpTime());
@@ -2555,8 +2556,8 @@ TEST_F(ReplCoordTest, MetadataUpdatesLastCommittedOpTime) {
     // lower OpTime, should not change
     StatusWith<rpc::ReplSetMetadata> metadata2 = rpc::ReplSetMetadata::readFromMetadata(BSON(
         rpc::kReplSetMetadataFieldName
-        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(9, 0) << "term" << 1) << "lastOpVisible"
-                                  << BSON("ts" << Timestamp(9, 0) << "term" << 1) << "configVersion"
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(9, 0) << "t" << 1) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(9, 0) << "t" << 1) << "configVersion"
                                   << 2 << "primaryIndex" << 2 << "term" << 1)));
     getReplCoord()->processReplSetMetadata(metadata2.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(10, 0), 1), getReplCoord()->getLastCommittedOpTime());
@@ -2584,10 +2585,10 @@ TEST_F(ReplCoordTest, MetadataUpdatesTermAndPrimaryId) {
 
     // higher term, should change
     StatusWith<rpc::ReplSetMetadata> metadata = rpc::ReplSetMetadata::readFromMetadata(BSON(
-        rpc::kReplSetMetadataFieldName << BSON(
-            "lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "term" << 3) << "lastOpVisible"
-                              << BSON("ts" << Timestamp(10, 0) << "term" << 3) << "configVersion"
-                              << 2 << "primaryIndex" << 2 << "term" << 3)));
+        rpc::kReplSetMetadataFieldName
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(10, 0) << "t" << 3) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(10, 0) << "t" << 3) << "configVersion"
+                                  << 2 << "primaryIndex" << 2 << "term" << 3)));
     getReplCoord()->processReplSetMetadata(metadata.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(10, 0), 3), getReplCoord()->getLastCommittedOpTime());
     ASSERT_EQUALS(3, getReplCoord()->getTerm());
@@ -2595,10 +2596,10 @@ TEST_F(ReplCoordTest, MetadataUpdatesTermAndPrimaryId) {
 
     // lower term, should not change
     StatusWith<rpc::ReplSetMetadata> metadata2 = rpc::ReplSetMetadata::readFromMetadata(BSON(
-        rpc::kReplSetMetadataFieldName << BSON(
-            "lastOpCommitted" << BSON("ts" << Timestamp(11, 0) << "term" << 3) << "lastOpVisible"
-                              << BSON("ts" << Timestamp(11, 0) << "term" << 3) << "configVersion"
-                              << 2 << "primaryIndex" << 1 << "term" << 2)));
+        rpc::kReplSetMetadataFieldName
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(11, 0) << "t" << 3) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(11, 0) << "t" << 3) << "configVersion"
+                                  << 2 << "primaryIndex" << 1 << "term" << 2)));
     getReplCoord()->processReplSetMetadata(metadata2.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(11, 0), 3), getReplCoord()->getLastCommittedOpTime());
     ASSERT_EQUALS(3, getReplCoord()->getTerm());
@@ -2606,10 +2607,10 @@ TEST_F(ReplCoordTest, MetadataUpdatesTermAndPrimaryId) {
 
     // same term, should not change
     StatusWith<rpc::ReplSetMetadata> metadata3 = rpc::ReplSetMetadata::readFromMetadata(BSON(
-        rpc::kReplSetMetadataFieldName << BSON(
-            "lastOpCommitted" << BSON("ts" << Timestamp(11, 0) << "term" << 3) << "lastOpVisible"
-                              << BSON("ts" << Timestamp(11, 0) << "term" << 3) << "configVersion"
-                              << 2 << "primaryIndex" << 1 << "term" << 3)));
+        rpc::kReplSetMetadataFieldName
+        << BSON("lastOpCommitted" << BSON("ts" << Timestamp(11, 0) << "t" << 3) << "lastOpVisible"
+                                  << BSON("ts" << Timestamp(11, 0) << "t" << 3) << "configVersion"
+                                  << 2 << "primaryIndex" << 1 << "term" << 3)));
     getReplCoord()->processReplSetMetadata(metadata3.getValue());
     ASSERT_EQUALS(OpTime(Timestamp(11, 0), 3), getReplCoord()->getLastCommittedOpTime());
     ASSERT_EQUALS(3, getReplCoord()->getTerm());
@@ -2954,7 +2955,8 @@ TEST_F(ReplCoordTest, LivenessForwardingForChainedMember) {
         BSONObj entry = entryElement.Obj();
         long long memberId = entry["memberId"].Number();
         memberIds.insert(memberId);
-        OpTime entryOpTime = OpTime::parseFromBSON(entry["optime"].Obj()).getValue();
+        OpTime entryOpTime;
+        bsonExtractOpTimeField(entry, "optime", &entryOpTime);
         ASSERT_EQUALS(optime, entryOpTime);
     }
     ASSERT_EQUALS(2U, memberIds.size());
@@ -2980,7 +2982,8 @@ TEST_F(ReplCoordTest, LivenessForwardingForChainedMember) {
         BSONObj entry = entryElement.Obj();
         long long memberId = entry["memberId"].Number();
         memberIds2.insert(memberId);
-        OpTime entryOpTime = OpTime::parseFromBSON(entry["optime"].Obj()).getValue();
+        OpTime entryOpTime;
+        bsonExtractOpTimeField(entry, "optime", &entryOpTime);
         ASSERT_EQUALS(optime, entryOpTime);
     }
     ASSERT_EQUALS(1U, memberIds2.size());
diff --git a/src/mongo/db/repl/rs_initialsync.cpp b/src/mongo/db/repl/rs_initialsync.cpp
index d62b86f20e9..9ee2d8a65a3 100644
--- a/src/mongo/db/repl/rs_initialsync.cpp
+++ b/src/mongo/db/repl/rs_initialsync.cpp
@@ -253,7 +253,7 @@ bool _initialSyncApplyOplog(OperationContext* ctx, repl::SyncTail& syncer, Oplog
         return false;
     }
 
-    OpTime stopOpTime = fassertStatusOK(28777, OpTime::parseFromBSON(lastOp));
+    OpTime stopOpTime = fassertStatusOK(28777, OpTime::parseFromOplogEntry(lastOp));
 
     // If we already have what we need then return.
     if (stopOpTime == startOpTime)
diff --git a/src/mongo/db/repl/rs_rollback.cpp b/src/mongo/db/repl/rs_rollback.cpp
index a78c36c57e5..a88528a57d0 100644
--- a/src/mongo/db/repl/rs_rollback.cpp
+++ b/src/mongo/db/repl/rs_rollback.cpp
@@ -323,7 +323,7 @@ void syncFixUp(OperationContext* txn,
 
     // we have items we are writing that aren't from a point-in-time.  thus best not to come
     // online until we get to that point in freshness.
-    OpTime minValid = fassertStatusOK(28774, OpTime::parseFromBSON(newMinValid));
+    OpTime minValid = fassertStatusOK(28774, OpTime::parseFromOplogEntry(newMinValid));
     log() << "minvalid=" << minValid;
     setMinValid(txn, minValid);
 
@@ -426,7 +426,7 @@ void syncFixUp(OperationContext* txn,
             if (newMinValid.isEmpty()) {
                 err = "can't get minvalid from sync source";
             } else {
-                OpTime minValid = fassertStatusOK(28775, OpTime::parseFromBSON(newMinValid));
+                OpTime minValid = fassertStatusOK(28775, OpTime::parseFromOplogEntry(newMinValid));
                 log() << "minvalid=" << minValid;
                 setMinValid(txn, minValid);
             }
diff --git a/src/mongo/db/repl/sync_tail.cpp b/src/mongo/db/repl/sync_tail.cpp
index 76c8633bf31..5d8029c5124 100644
--- a/src/mongo/db/repl/sync_tail.cpp
+++ b/src/mongo/db/repl/sync_tail.cpp
@@ -431,7 +431,8 @@ void SyncTail::_applyOplogUntil(OperationContext* txn, const OpTime& endOpTime)
 
             // Check if we reached the end
             const BSONObj currentOp = ops.back();
-            const OpTime currentOpTime = fassertStatusOK(28772, OpTime::parseFromBSON(currentOp));
+            const OpTime currentOpTime =
+                fassertStatusOK(28772, OpTime::parseFromOplogEntry(currentOp));
 
             // When we reach the end return this batch
             if (currentOpTime == endOpTime) {
@@ -591,7 +592,7 @@ void SyncTail::oplogApplication() {
         // Set minValid to the last op to be applied in this next batch.
         // This will cause this node to go into RECOVERING state
         // if we should crash and restart before updating the oplog
-        setMinValid(&txn, fassertStatusOK(28773, OpTime::parseFromBSON(lastOp)));
+        setMinValid(&txn, fassertStatusOK(28773, OpTime::parseFromOplogEntry(lastOp)));
         multiApply(&txn,
                    ops,
                    &_prefetcherPool,
diff --git a/src/mongo/db/repl/update_position_args.cpp b/src/mongo/db/repl/update_position_args.cpp
index 5151fbfe1f6..6ccddfa96aa 100644
--- a/src/mongo/db/repl/update_position_args.cpp
+++ b/src/mongo/db/repl/update_position_args.cpp
@@ -94,10 +94,9 @@ Status UpdatePositionArgs::initialize(const BSONObj& argsObj) {
         OpTime opTime;
         if (entry[kOpTimeFieldName].isABSONObj()) {
             // In protocol version 1, { ts: <timestamp>, t: term }
-            StatusWith<OpTime> opTimeStatus = OpTime::parseFromBSON(entry[kOpTimeFieldName].Obj());
-            if (!opTimeStatus.isOK())
-                return opTimeStatus.getStatus();
-            opTime = opTimeStatus.getValue();
+            Status status = bsonExtractOpTimeField(entry, kOpTimeFieldName, &opTime);
+            if (!status.isOK())
+                return status;
         } else {
             Timestamp ts;
             status = bsonExtractTimestampField(entry, kOpTimeFieldName, &ts);
diff --git a/src/mongo/db/repl/vote_requester.cpp b/src/mongo/db/repl/vote_requester.cpp
index 7bef97a148f..a8d24c3b496 100644
--- a/src/mongo/db/repl/vote_requester.cpp
+++ b/src/mongo/db/repl/vote_requester.cpp
@@ -75,7 +75,7 @@ std::vector<RemoteCommandRequest> VoteRequester::Algorithm::getRequests() const
 
     BSONObjBuilder lastCommittedOp(requestVotesCmdBuilder.subobjStart("lastCommittedOp"));
     lastCommittedOp.append("ts", _lastOplogEntry.getTimestamp());
-    lastCommittedOp.append("term", _lastOplogEntry.getTerm());
+    lastCommittedOp.append("t", _lastOplogEntry.getTerm());
     lastCommittedOp.done();
 
     const BSONObj requestVotesCmd = requestVotesCmdBuilder.obj();
diff --git a/src/mongo/rpc/metadata/repl_set_metadata.cpp b/src/mongo/rpc/metadata/repl_set_metadata.cpp
index 8ea6f2fa867..aadd520a683 100644
--- a/src/mongo/rpc/metadata/repl_set_metadata.cpp
+++ b/src/mongo/rpc/metadata/repl_set_metadata.cpp
@@ -46,7 +46,6 @@ const char kLastOpCommittedFieldName[] = "lastOpCommitted";
 const char kLastOpVisibleFieldName[] = "lastOpVisible";
 const char kConfigVersionFieldName[] = "configVersion";
 const char kPrimaryIndexFieldName[] = "primaryIndex";
-const char kTimestampFieldName[] = "ts";
 const char kTermFieldName[] = "term";
 
 }  // unnamed namespace
@@ -106,18 +105,8 @@ StatusWith<ReplSetMetadata> ReplSetMetadata::readFromMetadata(const BSONObj& met
 Status ReplSetMetadata::writeToMetadata(BSONObjBuilder* builder) const {
     BSONObjBuilder replMetadataBuilder(builder->subobjStart(kReplSetMetadataFieldName));
     replMetadataBuilder.append(kTermFieldName, _currentTerm);
-
-    BSONObjBuilder lastOpCommittedBuilder(
-        replMetadataBuilder.subobjStart(kLastOpCommittedFieldName));
-    lastOpCommittedBuilder.append(kTimestampFieldName, _lastOpCommitted.getTimestamp());
-    lastOpCommittedBuilder.append(kTermFieldName, _lastOpCommitted.getTerm());
-    lastOpCommittedBuilder.doneFast();
-
-    BSONObjBuilder lastOpVisibleBuilder(replMetadataBuilder.subobjStart(kLastOpVisibleFieldName));
-    lastOpVisibleBuilder.append(kTimestampFieldName, _lastOpVisible.getTimestamp());
-    lastOpVisibleBuilder.append(kTermFieldName, _lastOpVisible.getTerm());
-    lastOpVisibleBuilder.doneFast();
-
+    _lastOpCommitted.append(&replMetadataBuilder, kLastOpCommittedFieldName);
+    _lastOpVisible.append(&replMetadataBuilder, kLastOpVisibleFieldName);
     replMetadataBuilder.append(kConfigVersionFieldName, _configVersion);
     replMetadataBuilder.append(kPrimaryIndexFieldName, _currentPrimaryIndex);
     replMetadataBuilder.doneFast();
diff --git a/src/mongo/rpc/metadata/repl_set_metadata_test.cpp b/src/mongo/rpc/metadata/repl_set_metadata_test.cpp
index 82bff1f0209..499bbeb0b23 100644
--- a/src/mongo/rpc/metadata/repl_set_metadata_test.cpp
+++ b/src/mongo/rpc/metadata/repl_set_metadata_test.cpp
@@ -50,9 +50,9 @@ TEST(ReplResponseMetadataTest, Roundtrip) {
     BSONObj expectedObj(
         BSON(kReplSetMetadataFieldName
              << BSON("term" << 3 << "lastOpCommitted"
-                            << BSON("ts" << opTime.getTimestamp() << "term" << opTime.getTerm())
+                            << BSON("ts" << opTime.getTimestamp() << "t" << opTime.getTerm())
                             << "lastOpVisible"
-                            << BSON("ts" << opTime2.getTimestamp() << "term" << opTime2.getTerm())
+                            << BSON("ts" << opTime2.getTimestamp() << "t" << opTime2.getTerm())
                             << "configVersion" << 6 << "primaryIndex" << 12)));
 
     BSONObj serializedObj = builder.obj();
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp
index f7bb0b02520..b316d57e55c 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp
@@ -429,15 +429,15 @@ void CatalogManagerReplSetTestFixture::checkReadConcern(const BSONObj& cmdObj,
     auto readConcernObj = readConcernElem.Obj();
     ASSERT_EQ("majority", readConcernObj[repl::ReadConcernArgs::kLevelFieldName].str());
 
-    auto afterElem = readConcernObj[repl::ReadConcernArgs::kOpTimeFieldName];
+    auto afterElem = readConcernObj[repl::ReadConcernArgs::kAfterOpTimeFieldName];
     ASSERT_EQ(Object, afterElem.type());
 
     auto afterObj = afterElem.Obj();
 
-    ASSERT_TRUE(afterObj.hasField(repl::ReadConcernArgs::kOpTimestampFieldName));
-    ASSERT_EQ(expectedTS, afterObj[repl::ReadConcernArgs::kOpTimestampFieldName].timestamp());
-    ASSERT_TRUE(afterObj.hasField(repl::ReadConcernArgs::kOpTermFieldName));
-    ASSERT_EQ(expectedTerm, afterObj[repl::ReadConcernArgs::kOpTermFieldName].numberLong());
+    ASSERT_TRUE(afterObj.hasField(repl::OpTime::kTimestampFieldName));
+    ASSERT_EQ(expectedTS, afterObj[repl::OpTime::kTimestampFieldName].timestamp());
+    ASSERT_TRUE(afterObj.hasField(repl::OpTime::kTermFieldName));
+    ASSERT_EQ(expectedTerm, afterObj[repl::OpTime::kTermFieldName].numberLong());
 }
 
 }  // namespace mongo
diff --git a/src/mongo/s/chunk_version.cpp b/src/mongo/s/chunk_version.cpp
index 305875d4a6e..ff926d4db3e 100644
--- a/src/mongo/s/chunk_version.cpp
+++ b/src/mongo/s/chunk_version.cpp
@@ -111,7 +111,7 @@ StatusWith<ChunkVersionAndOpTime> ChunkVersionAndOpTime::parseFromBSONForCommand
 
     const ChunkVersion& chunkVersion = chunkVersionStatus.getValue();
 
-    const auto opTimeStatus = repl::OpTime::parseFromBSON(obj);
+    const auto opTimeStatus = repl::OpTime::parseFromOplogEntry(obj);
     if (opTimeStatus.isOK()) {
         return ChunkVersionAndOpTime(chunkVersion, opTimeStatus.getValue());
     } else if (opTimeStatus == ErrorCodes::NoSuchKey) {
@@ -129,7 +129,7 @@ StatusWith<ChunkVersionAndOpTime> ChunkVersionAndOpTime::parseFromBSONForSetShar
 
     const ChunkVersion& chunkVersion = chunkVersionStatus.getValue();
 
-    const auto opTimeStatus = repl::OpTime::parseFromBSON(obj);
+    const auto opTimeStatus = repl::OpTime::parseFromOplogEntry(obj);
     if (opTimeStatus.isOK()) {
         return ChunkVersionAndOpTime(chunkVersion, opTimeStatus.getValue());
     } else if (opTimeStatus == ErrorCodes::NoSuchKey) {
@@ -141,12 +141,14 @@ StatusWith<ChunkVersionAndOpTime> ChunkVersionAndOpTime::parseFromBSONForSetShar
 
 void ChunkVersionAndOpTime::appendForSetShardVersion(BSONObjBuilder* builder) const {
     _verAndOpT.value.addToBSON(*builder, kVersion);
-    _verAndOpT.opTime.append(builder);
+    builder->append("ts", _verAndOpT.opTime.getTimestamp());
+    builder->append("t", _verAndOpT.opTime.getTerm());
 }
 
 void ChunkVersionAndOpTime::appendForCommands(BSONObjBuilder* builder) const {
     builder->appendArray(kShardVersion, _verAndOpT.value.toBSON());
-    _verAndOpT.opTime.append(builder);
+    builder->append("ts", _verAndOpT.opTime.getTimestamp());
+    builder->append("t", _verAndOpT.opTime.getTerm());
 }
 
 }  // namespace mongo
diff --git a/src/mongo/util/assert_util.h b/src/mongo/util/assert_util.h
index b14b50b3036..e21bed06561 100644
--- a/src/mongo/util/assert_util.h
+++ b/src/mongo/util/assert_util.h
@@ -270,6 +270,12 @@ inline T fassertStatusOK(int msgid, StatusWith<T> sw) {
     return std::move(sw.getValue());
 }
 
+inline void fassertStatusOK(int msgid, const Status& s) {
+    if (MONGO_unlikely(!s.isOK())) {
+        fassertFailedWithStatus(msgid, s);
+    }
+}
+
 /* warning only - keeps going */
 #define MONGO_wassert(_Expression)                                \
     do {                                                          \