Revert "SERVER-31678 Thread through the operation wall-clock time for oplog entries"

This reverts commit 080514c9ee36564d8342cd832f3c5f3a199a9845.

8 files changed, 32 insertions, 230 deletions

diff --git a/src/mongo/db/commands/dbcheck.cpp b/src/mongo/db/commands/dbcheck.cpp
index fe7bcd178c6..3650b93af48 100644
--- a/src/mongo/db/commands/dbcheck.cpp
+++ b/src/mongo/db/commands/dbcheck.cpp
@@ -461,21 +461,9 @@ private:
                         const BSONObj& obj) {
         return writeConflictRetry(
             opCtx, "dbCheck oplog entry", NamespaceString::kRsOplogNamespace.ns(), [&] {
-                auto const clockSource = opCtx->getServiceContext()->getFastClockSource();
-                const auto wallClockTime = clockSource->now();
-
                 WriteUnitOfWork uow(opCtx);
-                repl::OpTime result = repl::logOp(opCtx,
-                                                  "c",
-                                                  nss,
-                                                  uuid,
-                                                  obj,
-                                                  nullptr,
-                                                  false,
-                                                  wallClockTime,
-                                                  {},
-                                                  kUninitializedStmtId,
-                                                  {});
+                repl::OpTime result = repl::logOp(
+                    opCtx, "c", nss, uuid, obj, nullptr, false, {}, kUninitializedStmtId, {});
                 uow.commit();
                 return result;
             });
diff --git a/src/mongo/db/op_observer_impl.cpp b/src/mongo/db/op_observer_impl.cpp
index 5621f9da8a2..0f3c08b0e07 100644
--- a/src/mongo/db/op_observer_impl.cpp
+++ b/src/mongo/db/op_observer_impl.cpp
@@ -117,15 +117,9 @@ BSONObj makeCollModCmdObj(const BSONObj& collModCmd,
     return cmdObjBuilder.obj();
 }
 
-Date_t getWallClockTimeForOpLog(OperationContext* opCtx) {
-    auto const clockSource = opCtx->getServiceContext()->getFastClockSource();
-    return clockSource->now();
-}
-
 struct OpTimeBundle {
     repl::OpTime writeOpTime;
     repl::OpTime prePostImageOpTime;
-    Date_t wallClockTime;
 };
 
 /**
@@ -152,7 +146,6 @@ OpTimeBundle replLogUpdate(OperationContext* opCtx,
     }
 
     OpTimeBundle opTimes;
-    opTimes.wallClockTime = getWallClockTimeForOpLog(opCtx);
 
     if (!storeObj.isEmpty() && opCtx->getTxnNumber()) {
         auto noteUpdateOpTime = repl::logOp(opCtx,
@@ -162,7 +155,6 @@ OpTimeBundle replLogUpdate(OperationContext* opCtx,
                                             storeObj,
                                             nullptr,
                                             false,
-                                            opTimes.wallClockTime,
                                             sessionInfo,
                                             args.stmtId,
                                             {});
@@ -183,7 +175,6 @@ OpTimeBundle replLogUpdate(OperationContext* opCtx,
                                       args.update,
                                       &args.criteria,
                                       args.fromMigrate,
-                                      opTimes.wallClockTime,
                                       sessionInfo,
                                       args.stmtId,
                                       oplogLink);
@@ -212,20 +203,10 @@ OpTimeBundle replLogDelete(OperationContext* opCtx,
     }
 
     OpTimeBundle opTimes;
-    opTimes.wallClockTime = getWallClockTimeForOpLog(opCtx);
 
     if (deletedDoc && opCtx->getTxnNumber()) {
-        auto noteOplog = repl::logOp(opCtx,
-                                     "n",
-                                     nss,
-                                     uuid,
-                                     deletedDoc.get(),
-                                     nullptr,
-                                     false,
-                                     opTimes.wallClockTime,
-                                     sessionInfo,
-                                     stmtId,
-                                     {});
+        auto noteOplog = repl::logOp(
+            opCtx, "n", nss, uuid, deletedDoc.get(), nullptr, false, sessionInfo, stmtId, {});
         opTimes.prePostImageOpTime = noteOplog;
         oplogLink.preImageOpTime = noteOplog;
     }
@@ -237,7 +218,6 @@ OpTimeBundle replLogDelete(OperationContext* opCtx,
                                       deleteState.documentKey,
                                       nullptr,
                                       fromMigrate,
-                                      opTimes.wallClockTime,
                                       sessionInfo,
                                       stmtId,
                                       oplogLink);
@@ -269,7 +249,6 @@ void OpObserverImpl::onCreateIndex(OperationContext* opCtx,
                     builder.done(),
                     nullptr,
                     fromMigrate,
-                    getWallClockTimeForOpLog(opCtx),
                     {},
                     kUninitializedStmtId,
                     {});
@@ -281,7 +260,6 @@ void OpObserverImpl::onCreateIndex(OperationContext* opCtx,
                     indexDoc,
                     nullptr,
                     fromMigrate,
-                    getWallClockTimeForOpLog(opCtx),
                     {},
                     kUninitializedStmtId,
                     {});
@@ -304,8 +282,7 @@ void OpObserverImpl::onInserts(OperationContext* opCtx,
                                bool fromMigrate) {
     Session* const session = opCtx->getTxnNumber() ? OperationContextSession::get(opCtx) : nullptr;
 
-    const auto opTimeList = repl::logInsertOps(
-        opCtx, nss, uuid, session, begin, end, fromMigrate, getWallClockTimeForOpLog(opCtx));
+    const auto opTimeList = repl::logInsertOps(opCtx, nss, uuid, session, begin, end, fromMigrate);
 
     auto css = CollectionShardingState::get(opCtx, nss.ns());
 
@@ -443,17 +420,7 @@ void OpObserverImpl::onInternalOpMessage(OperationContext* opCtx,
                                          const BSONObj& msgObj,
                                          const boost::optional<BSONObj> o2MsgObj) {
     const BSONObj* o2MsgPtr = o2MsgObj ? o2MsgObj.get_ptr() : nullptr;
-    repl::logOp(opCtx,
-                "n",
-                nss,
-                uuid,
-                msgObj,
-                o2MsgPtr,
-                false,
-                getWallClockTimeForOpLog(opCtx),
-                {},
-                kUninitializedStmtId,
-                {});
+    repl::logOp(opCtx, "n", nss, uuid, msgObj, o2MsgPtr, false, {}, kUninitializedStmtId, {});
 }
 
 void OpObserverImpl::onCreateCollection(OperationContext* opCtx,
@@ -486,17 +453,8 @@ void OpObserverImpl::onCreateCollection(OperationContext* opCtx,
 
     if (!collectionName.isSystemDotProfile()) {
         // do not replicate system.profile modifications
-        repl::logOp(opCtx,
-                    "c",
-                    cmdNss,
-                    options.uuid,
-                    cmdObj,
-                    nullptr,
-                    false,
-                    getWallClockTimeForOpLog(opCtx),
-                    {},
-                    kUninitializedStmtId,
-                    {});
+        repl::logOp(
+            opCtx, "c", cmdNss, options.uuid, cmdObj, nullptr, false, {}, kUninitializedStmtId, {});
     }
 
     AuthorizationManager::get(opCtx->getServiceContext())
@@ -534,17 +492,7 @@ void OpObserverImpl::onCollMod(OperationContext* opCtx,
 
     if (!nss.isSystemDotProfile()) {
         // do not replicate system.profile modifications
-        repl::logOp(opCtx,
-                    "c",
-                    cmdNss,
-                    uuid,
-                    cmdObj,
-                    &o2Obj,
-                    false,
-                    getWallClockTimeForOpLog(opCtx),
-                    {},
-                    kUninitializedStmtId,
-                    {});
+        repl::logOp(opCtx, "c", cmdNss, uuid, cmdObj, &o2Obj, false, {}, kUninitializedStmtId, {});
     }
 
     AuthorizationManager::get(opCtx->getServiceContext())
@@ -574,17 +522,7 @@ void OpObserverImpl::onDropDatabase(OperationContext* opCtx, const std::string&
     const NamespaceString cmdNss{dbName, "$cmd"};
     const auto cmdObj = BSON("dropDatabase" << 1);
 
-    repl::logOp(opCtx,
-                "c",
-                cmdNss,
-                {},
-                cmdObj,
-                nullptr,
-                false,
-                getWallClockTimeForOpLog(opCtx),
-                {},
-                kUninitializedStmtId,
-                {});
+    repl::logOp(opCtx, "c", cmdNss, {}, cmdObj, nullptr, false, {}, kUninitializedStmtId, {});
 
     if (dbName == FeatureCompatibilityVersion::kDatabase) {
         FeatureCompatibilityVersion::onDropCollection(opCtx);
@@ -607,17 +545,8 @@ repl::OpTime OpObserverImpl::onDropCollection(OperationContext* opCtx,
     repl::OpTime dropOpTime;
     if (!collectionName.isSystemDotProfile()) {
         // Do not replicate system.profile modifications
-        dropOpTime = repl::logOp(opCtx,
-                                 "c",
-                                 cmdNss,
-                                 uuid,
-                                 cmdObj,
-                                 nullptr,
-                                 false,
-                                 getWallClockTimeForOpLog(opCtx),
-                                 {},
-                                 kUninitializedStmtId,
-                                 {});
+        dropOpTime = repl::logOp(
+            opCtx, "c", cmdNss, uuid, cmdObj, nullptr, false, {}, kUninitializedStmtId, {});
     }
 
     if (collectionName.coll() == DurableViewCatalog::viewsCollectionName()) {
@@ -654,17 +583,7 @@ void OpObserverImpl::onDropIndex(OperationContext* opCtx,
     const auto cmdNss = nss.getCommandNS();
     const auto cmdObj = BSON("dropIndexes" << nss.coll() << "index" << indexName);
 
-    repl::logOp(opCtx,
-                "c",
-                cmdNss,
-                uuid,
-                cmdObj,
-                &indexInfo,
-                false,
-                getWallClockTimeForOpLog(opCtx),
-                {},
-                kUninitializedStmtId,
-                {});
+    repl::logOp(opCtx, "c", cmdNss, uuid, cmdObj, &indexInfo, false, {}, kUninitializedStmtId, {});
 
     AuthorizationManager::get(opCtx->getServiceContext())
         ->logOp(opCtx, "c", cmdNss, cmdObj, &indexInfo);
@@ -691,17 +610,8 @@ repl::OpTime OpObserverImpl::onRenameCollection(OperationContext* opCtx,
 
     const auto cmdObj = builder.done();
 
-    const auto renameOpTime = repl::logOp(opCtx,
-                                          "c",
-                                          cmdNss,
-                                          uuid,
-                                          cmdObj,
-                                          nullptr,
-                                          false,
-                                          getWallClockTimeForOpLog(opCtx),
-                                          {},
-                                          kUninitializedStmtId,
-                                          {});
+    const auto renameOpTime =
+        repl::logOp(opCtx, "c", cmdNss, uuid, cmdObj, nullptr, false, {}, kUninitializedStmtId, {});
 
     if (fromCollection.isSystemDotViews())
         DurableViewCatalog::onExternalChange(opCtx, fromCollection);
@@ -737,17 +647,7 @@ void OpObserverImpl::onApplyOps(OperationContext* opCtx,
                                 const std::string& dbName,
                                 const BSONObj& applyOpCmd) {
     const NamespaceString cmdNss{dbName, "$cmd"};
-    repl::logOp(opCtx,
-                "c",
-                cmdNss,
-                {},
-                applyOpCmd,
-                nullptr,
-                false,
-                getWallClockTimeForOpLog(opCtx),
-                {},
-                kUninitializedStmtId,
-                {});
+    repl::logOp(opCtx, "c", cmdNss, {}, applyOpCmd, nullptr, false, {}, kUninitializedStmtId, {});
 
     AuthorizationManager::get(opCtx->getServiceContext())
         ->logOp(opCtx, "c", cmdNss, applyOpCmd, nullptr);
@@ -761,17 +661,7 @@ void OpObserverImpl::onEmptyCapped(OperationContext* opCtx,
 
     if (!collectionName.isSystemDotProfile()) {
         // Do not replicate system.profile modifications
-        repl::logOp(opCtx,
-                    "c",
-                    cmdNss,
-                    uuid,
-                    cmdObj,
-                    nullptr,
-                    false,
-                    getWallClockTimeForOpLog(opCtx),
-                    {},
-                    kUninitializedStmtId,
-                    {});
+        repl::logOp(opCtx, "c", cmdNss, uuid, cmdObj, nullptr, false, {}, kUninitializedStmtId, {});
     }
 
     AuthorizationManager::get(opCtx->getServiceContext())
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index 8fd70dff826..b7503de1082 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -408,7 +408,6 @@ OpTime logOp(OperationContext* opCtx,
              const BSONObj& obj,
              const BSONObj* o2,
              bool fromMigrate,
-             Date_t wallClockTime,
              const OperationSessionInfo& sessionInfo,
              StmtId statementId,
              const OplogLink& oplogLink) {
@@ -435,7 +434,7 @@ OpTime logOp(OperationContext* opCtx,
                                fromMigrate,
                                slot.opTime,
                                slot.hash,
-                               wallClockTime,
+                               Date_t::now(),
                                sessionInfo,
                                statementId,
                                oplogLink);
@@ -452,8 +451,7 @@ std::vector<OpTime> logInsertOps(OperationContext* opCtx,
                                  Session* session,
                                  std::vector<InsertStatement>::const_iterator begin,
                                  std::vector<InsertStatement>::const_iterator end,
-                                 bool fromMigrate,
-                                 Date_t wallClockTime) {
+                                 bool fromMigrate) {
     invariant(begin != end);
 
     auto replCoord = ReplicationCoordinator::get(opCtx);
@@ -470,6 +468,7 @@ std::vector<OpTime> logInsertOps(OperationContext* opCtx,
     Lock::CollectionLock lock(opCtx->lockState(), _oplogCollectionName, MODE_IX);
 
     WriteUnitOfWork wuow(opCtx);
+    auto wallTime = Date_t::now();
 
     OperationSessionInfo sessionInfo;
     OplogLink oplogLink;
@@ -498,7 +497,7 @@ std::vector<OpTime> logInsertOps(OperationContext* opCtx,
                                           fromMigrate,
                                           insertStatementOplogSlot.opTime,
                                           insertStatementOplogSlot.hash,
-                                          wallClockTime,
+                                          wallTime,
                                           sessionInfo,
                                           begin[i].stmtId,
                                           oplogLink));
diff --git a/src/mongo/db/repl/oplog.h b/src/mongo/db/repl/oplog.h
index df2178a66aa..78f1c4f8103 100644
--- a/src/mongo/db/repl/oplog.h
+++ b/src/mongo/db/repl/oplog.h
@@ -110,8 +110,7 @@ std::vector<OpTime> logInsertOps(OperationContext* opCtx,
                                  Session* session,
                                  std::vector<InsertStatement>::const_iterator begin,
                                  std::vector<InsertStatement>::const_iterator end,
-                                 bool fromMigrate,
-                                 Date_t wallClockTime);
+                                 bool fromMigrate);
 
 /**
  * @param opstr
@@ -125,9 +124,6 @@ std::vector<OpTime> logInsertOps(OperationContext* opCtx,
  * For 'u' records, 'obj' captures the mutation made to the object but not
  * the object itself. 'o2' captures the the criteria for the object that will be modified.
  *
- * wallClockTime this specifies the wall-clock timestamp of then this oplog entry was generated. It
- *   is purely informational, may not be monotonically increasing and is not interpreted in any way
- *   by the replication subsystem.
  * oplogLink this contains the timestamp that points to the previous write that will be
  *   linked via prevTs, and the timestamps of the oplog entry that contains the document
  *   before/after update was applied. The timestamps are ignored if isNull() is true.
@@ -142,7 +138,6 @@ OpTime logOp(OperationContext* opCtx,
              const BSONObj& obj,
              const BSONObj* o2,
              bool fromMigrate,
-             Date_t wallClockTime,
              const OperationSessionInfo& sessionInfo,
              StmtId stmtId,
              const OplogLink& oplogLink);
diff --git a/src/mongo/db/repl/oplog_test.cpp b/src/mongo/db/repl/oplog_test.cpp
index 7666e026955..cad60def20f 100644
--- a/src/mongo/db/repl/oplog_test.cpp
+++ b/src/mongo/db/repl/oplog_test.cpp
@@ -100,17 +100,8 @@ TEST_F(OplogTest, LogOpReturnsOpTimeOnSuccessfulInsertIntoOplogCollection) {
     {
         AutoGetDb autoDb(opCtx.get(), nss.db(), MODE_X);
         WriteUnitOfWork wunit(opCtx.get());
-        opTime = logOp(opCtx.get(),
-                       "n",
-                       nss,
-                       {},
-                       msgObj,
-                       nullptr,
-                       false,
-                       Date_t::now(),
-                       {},
-                       kUninitializedStmtId,
-                       {});
+        opTime =
+            logOp(opCtx.get(), "n", nss, {}, msgObj, nullptr, false, {}, kUninitializedStmtId, {});
         ASSERT_FALSE(opTime.isNull());
         wunit.commit();
     }
@@ -222,8 +213,7 @@ OpTime _logOpNoopWithMsg(OperationContext* opCtx,
     // logOp() must be called while holding lock because ephemeralForTest storage engine does not
     // support concurrent updates to its internal state.
     const auto msgObj = BSON("msg" << nss.ns());
-    auto opTime = logOp(
-        opCtx, "n", nss, {}, msgObj, nullptr, false, Date_t::now(), {}, kUninitializedStmtId, {});
+    auto opTime = logOp(opCtx, "n", nss, {}, msgObj, nullptr, false, {}, kUninitializedStmtId, {});
     ASSERT_FALSE(opTime.isNull());
 
     ASSERT(opTimeNssMap->find(opTime) == opTimeNssMap->end())
diff --git a/src/mongo/db/s/session_catalog_migration_destination.cpp b/src/mongo/db/s/session_catalog_migration_destination.cpp
index 461d53e40b2..cdf0f0a778d 100644
--- a/src/mongo/db/s/session_catalog_migration_destination.cpp
+++ b/src/mongo/db/s/session_catalog_migration_destination.cpp
@@ -242,10 +242,6 @@ ProcessOplogResult processSessionOplog(OperationContext* opCtx,
     result.txnNum = sessionInfo.getTxnNumber().value();
     const auto stmtId = *oplogEntry.getStatementId();
 
-    // Session oplog entries must always contain wall clock time, because we will not be
-    // transferring anything from a previous version of the server
-    invariant(oplogEntry.getWallClockTime());
-
     auto scopedSession = SessionCatalog::get(opCtx)->getOrCreateSession(opCtx, result.sessionId);
     scopedSession->beginTxn(opCtx, result.txnNum);
 
@@ -289,7 +285,6 @@ ProcessOplogResult processSessionOplog(OperationContext* opCtx,
                                                           object,
                                                           &object2,
                                                           true,
-                                                          *oplogEntry.getWallClockTime(),
                                                           sessionInfo,
                                                           stmtId,
                                                           oplogLink);
diff --git a/src/mongo/db/s/session_catalog_migration_destination_test.cpp b/src/mongo/db/s/session_catalog_migration_destination_test.cpp
index 99ee8eae5d8..45ef7d0350c 100644
--- a/src/mongo/db/s/session_catalog_migration_destination_test.cpp
+++ b/src/mongo/db/s/session_catalog_migration_destination_test.cpp
@@ -298,17 +298,14 @@ TEST_F(SessionCatalogMigrationDestinationTest, OplogEntriesWithSameTxn) {
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     OplogEntry oplog3(OpTime(Timestamp(60, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 60));
     oplog3.setOperationSessionInfo(sessionInfo);
     oplog3.setStatementId(5);
-    oplog3.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2, oplog3});
 
@@ -350,19 +347,16 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldOnlyStoreHistoryOfLatestTxn
     sessionInfo.setTxnNumber(txnNum++);
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     sessionInfo.setTxnNumber(txnNum++);
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     OplogEntry oplog3(OpTime(Timestamp(60, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 60));
     sessionInfo.setTxnNumber(txnNum);
     oplog3.setOperationSessionInfo(sessionInfo);
     oplog3.setStatementId(5);
-    oplog3.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2, oplog3});
 
@@ -394,19 +388,17 @@ TEST_F(SessionCatalogMigrationDestinationTest, OplogEntriesWithSameTxnInSeparate
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     OplogEntry oplog3(OpTime(Timestamp(60, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 60));
     oplog3.setOperationSessionInfo(sessionInfo);
     oplog3.setStatementId(5);
-    oplog3.setWallClockTime(Date_t::now());
 
     // Return in 2 batches
+
     returnOplog({oplog1, oplog2});
     returnOplog({oplog3});
 
@@ -452,17 +444,14 @@ TEST_F(SessionCatalogMigrationDestinationTest, OplogEntriesWithDifferentSession)
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo1);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(sessionInfo2);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     OplogEntry oplog3(OpTime(Timestamp(60, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 60));
     oplog3.setOperationSessionInfo(sessionInfo2);
     oplog3.setStatementId(5);
-    oplog3.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2, oplog3});
 
@@ -529,7 +518,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldNotNestAlreadyNestedOplog)
                       origInnerOplog1.toBSON());
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(1080, 2), 1),
                       0,
@@ -540,7 +528,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldNotNestAlreadyNestedOplog)
                       origInnerOplog2.toBSON());
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2});
 
@@ -578,7 +565,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldBeAbleToHandlePreImageFindA
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     preImageOplog.setOperationSessionInfo(sessionInfo);
     preImageOplog.setStatementId(45);
-    preImageOplog.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -589,7 +575,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldBeAbleToHandlePreImageFindA
                            BSON("$set" << BSON("x" << 101)));
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPreImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({preImageOplog, updateOplog});
@@ -667,7 +652,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldBeAbleToHandlePostImageFind
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     postImageOplog.setOperationSessionInfo(sessionInfo);
     postImageOplog.setStatementId(45);
-    postImageOplog.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -678,7 +662,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldBeAbleToHandlePostImageFind
                            BSON("$set" << BSON("x" << 101)));
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPostImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({postImageOplog, updateOplog});
@@ -756,7 +739,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldBeAbleToHandleFindAndModify
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     preImageOplog.setOperationSessionInfo(sessionInfo);
     preImageOplog.setStatementId(45);
-    preImageOplog.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -767,7 +749,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldBeAbleToHandleFindAndModify
                            BSON("$set" << BSON("x" << 101)));
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPreImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({preImageOplog});
@@ -860,12 +841,10 @@ TEST_F(SessionCatalogMigrationDestinationTest, OlderTxnShouldBeIgnored) {
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(oldSessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(oldSessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2});
 
@@ -904,7 +883,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, NewerTxnWriteShouldNotBeOverwritt
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(oldSessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1});
 
@@ -924,7 +902,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, NewerTxnWriteShouldNotBeOverwritt
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(oldSessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     returnOplog({oplog2});
 
@@ -1005,7 +982,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldJoinProperlyForResponseWith
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog.setOperationSessionInfo(sessionInfo);
     oplog.setStatementId(23);
-    oplog.setWallClockTime(Date_t::now());
 
     returnOplog({oplog});
 
@@ -1028,7 +1004,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldJoinProperlyForResponseWith
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog.setOperationSessionInfo(sessionInfo);
     oplog.setStatementId(23);
-    oplog.setWallClockTime(Date_t::now());
 
     returnOplog({oplog});
 
@@ -1052,7 +1027,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldJoinProperlyForResponseWith
     OplogEntry oplog(
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog.setOperationSessionInfo(sessionInfo);
-    oplog.setWallClockTime(Date_t::now());
 
     returnOplog({oplog});
 
@@ -1079,7 +1053,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1});
 
@@ -1095,7 +1068,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
     OplogEntry oplog2(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(45);
-    oplog2.setWallClockTime(Date_t::now());
 
     returnOplog({oplog2});
 
@@ -1136,19 +1108,17 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldErrorForConsecutivePreImage
     sessionInfo.setSessionId(sessionId);
     sessionInfo.setTxnNumber(2);
 
-    OplogEntry preImageOplog1(
+    OplogEntry preImageOplog(
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
-    preImageOplog1.setOperationSessionInfo(sessionInfo);
-    preImageOplog1.setStatementId(45);
-    preImageOplog1.setWallClockTime(Date_t::now());
+    preImageOplog.setOperationSessionInfo(sessionInfo);
+    preImageOplog.setStatementId(45);
 
     OplogEntry preImageOplog2(
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     preImageOplog2.setOperationSessionInfo(sessionInfo);
     preImageOplog2.setStatementId(45);
-    preImageOplog2.setWallClockTime(Date_t::now());
 
-    returnOplog({preImageOplog1, preImageOplog2});
+    returnOplog({preImageOplog, preImageOplog2});
 
     sessionMigration.join();
 
@@ -1175,7 +1145,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     preImageOplog.setOperationSessionInfo(sessionInfo);
     preImageOplog.setStatementId(45);
-    preImageOplog.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -1187,7 +1156,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
     sessionInfo.setSessionId(makeLogicalSessionIdForTest());
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPreImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({preImageOplog, updateOplog});
@@ -1217,7 +1185,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldErrorForPreImageOplogWithNo
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     preImageOplog.setOperationSessionInfo(sessionInfo);
     preImageOplog.setStatementId(45);
-    preImageOplog.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -1229,7 +1196,6 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldErrorForPreImageOplogWithNo
     sessionInfo.setTxnNumber(56);
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPreImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({preImageOplog, updateOplog});
@@ -1260,7 +1226,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, BSON("x" << 100));
     preImageOplog.setOperationSessionInfo(sessionInfo);
     preImageOplog.setStatementId(45);
-    preImageOplog.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -1271,7 +1236,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
                            BSON("$set" << BSON("x" << 101)));
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
 
     returnOplog({preImageOplog, updateOplog});
 
@@ -1301,7 +1265,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -1312,7 +1275,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
                            BSON("$set" << BSON("x" << 101)));
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPreImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({oplog1, updateOplog});
@@ -1343,7 +1305,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry updateOplog(OpTime(Timestamp(80, 2), 1),
                            0,
@@ -1354,7 +1315,6 @@ TEST_F(SessionCatalogMigrationDestinationTest,
                            BSON("$set" << BSON("x" << 101)));
     updateOplog.setOperationSessionInfo(sessionInfo);
     updateOplog.setStatementId(45);
-    updateOplog.setWallClockTime(Date_t::now());
     updateOplog.setPostImageOpTime(repl::OpTime(Timestamp(100, 2), 1));
 
     returnOplog({oplog1, updateOplog});
@@ -1384,17 +1344,14 @@ TEST_F(SessionCatalogMigrationDestinationTest, ShouldIgnoreAlreadyExecutedStatem
         OpTime(Timestamp(60, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(OpTime(Timestamp(70, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(30);
-    oplog2.setWallClockTime(Date_t::now());
 
     OplogEntry oplog3(OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 80));
     oplog3.setOperationSessionInfo(sessionInfo);
     oplog3.setStatementId(45);
-    oplog3.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2, oplog3});
 
@@ -1438,18 +1395,15 @@ TEST_F(SessionCatalogMigrationDestinationTest, OplogEntriesWithIncompleteHistory
         OpTime(Timestamp(100, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 100));
     oplog1.setOperationSessionInfo(sessionInfo);
     oplog1.setStatementId(23);
-    oplog1.setWallClockTime(Date_t::now());
 
     OplogEntry oplog2(
         OpTime(Timestamp(80, 2), 1), 0, OpTypeEnum::kNoop, kNs, 0, {}, Session::kDeadEndSentinel);
     oplog2.setOperationSessionInfo(sessionInfo);
     oplog2.setStatementId(kIncompleteHistoryStmtId);
-    oplog2.setWallClockTime(Date_t::now());
 
     OplogEntry oplog3(OpTime(Timestamp(60, 2), 1), 0, OpTypeEnum::kInsert, kNs, 0, BSON("x" << 60));
     oplog3.setOperationSessionInfo(sessionInfo);
     oplog3.setStatementId(5);
-    oplog3.setWallClockTime(Date_t::now());
 
     returnOplog({oplog1, oplog2, oplog3});
     // migration always fetches at least twice to transition from committing to done.
diff --git a/src/mongo/db/session_test.cpp b/src/mongo/db/session_test.cpp
index a7b1690b369..15cbcd8ba27 100644
--- a/src/mongo/db/session_test.cpp
+++ b/src/mongo/db/session_test.cpp
@@ -84,17 +84,8 @@ protected:
         repl::OplogLink link;
         link.prevOpTime = prevOpTime;
 
-        return repl::logOp(opCtx,
-                           "n",
-                           nss,
-                           kUUID,
-                           BSON("TestValue" << 0),
-                           nullptr,
-                           false,
-                           Date_t::now(),
-                           osi,
-                           stmtId,
-                           link);
+        return repl::logOp(
+            opCtx, "n", nss, kUUID, BSON("TestValue" << 0), nullptr, false, osi, stmtId, link);
     }
 };