SERVER-39989 Use a config.transactions find command for the begin fetching optime in initial sync

4 files changed, 395 insertions, 277 deletions

diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index 15a21c4fe4a..9faed308ad6 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -1529,6 +1529,7 @@ env.Library(
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/client/fetcher',
+        '$BUILD_DIR/mongo/db/transaction',
         '$BUILD_DIR/mongo/db/commands/server_status_core',
         'collection_cloner',
         'database_cloner',
diff --git a/src/mongo/db/repl/initial_syncer.cpp b/src/mongo/db/repl/initial_syncer.cpp
index b074341d4a3..b41a20510c6 100644
--- a/src/mongo/db/repl/initial_syncer.cpp
+++ b/src/mongo/db/repl/initial_syncer.cpp
@@ -58,6 +58,7 @@
 #include "mongo/db/repl/replication_process.h"
 #include "mongo/db/repl/storage_interface.h"
 #include "mongo/db/repl/sync_source_selector.h"
+#include "mongo/db/session_txn_record_gen.h"
 #include "mongo/executor/task_executor.h"
 #include "mongo/executor/thread_pool_task_executor.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
@@ -306,6 +307,7 @@ void InitialSyncer::_cancelRemainingWork_inlock() {
     _shutdownComponent_inlock(_applier);
     _shutdownComponent_inlock(_fCVFetcher);
     _shutdownComponent_inlock(_lastOplogEntryFetcher);
+    _shutdownComponent_inlock(_beginFetchingOpTimeFetcher);
 }
 
 void InitialSyncer::join() {
@@ -644,21 +646,44 @@ Status InitialSyncer::_truncateOplogAndDropReplicatedDatabases() {
 
 Status InitialSyncer::_scheduleGetBeginFetchingOpTime_inlock(
     std::shared_ptr<OnCompletionGuard> onCompletionGuard) {
-    // We will ultimately be getting oldestActiveOplogEntryOpTime from the transactions field in
-    // serverStatus to use as the beginFetchingTimestamp. Also, we project out the metrics and
-    // wiredTiger fields because we don't need them and they're very large.
-    executor::RemoteCommandRequest request(
-        _syncSource,
-        "admin",
-        BSON("serverStatus" << 1 << "transactions" << 1 << "metrics" << 0 << "wiredTiger" << 0),
-        nullptr);
-
-    auto scheduleResultSW = _exec->scheduleRemoteCommand(
-        request, [=](const executor::TaskExecutor::RemoteCommandCallbackArgs& callbackData) {
-            _getBeginFetchingOpTimeCallback(callbackData.response, onCompletionGuard);
-        });
 
-    return scheduleResultSW.getStatus();
+    const auto preparedState = DurableTxnState_serializer(DurableTxnStateEnum::kPrepared);
+    const auto inProgressState = DurableTxnState_serializer(DurableTxnStateEnum::kInProgress);
+
+    // Obtain the oldest active transaction timestamp from the remote by querying their
+    // transactions table.
+    BSONObjBuilder cmd;
+    cmd.append("find", NamespaceString::kSessionTransactionsTableNamespace.coll().toString());
+    cmd.append("filter",
+               BSON("state" << BSON("$in" << BSON_ARRAY(preparedState << inProgressState))));
+    cmd.append("sort", BSON(SessionTxnRecord::kStartOpTimeFieldName << 1));
+    cmd.append("readConcern",
+               BSON("level"
+                    << "local"));
+    cmd.append("limit", 1);
+
+    _beginFetchingOpTimeFetcher = stdx::make_unique<Fetcher>(
+        _exec,
+        _syncSource,
+        NamespaceString::kSessionTransactionsTableNamespace.db().toString(),
+        cmd.obj(),
+        [=](const StatusWith<mongo::Fetcher::QueryResponse>& response,
+            mongo::Fetcher::NextAction*,
+            mongo::BSONObjBuilder*) mutable {
+            _getBeginFetchingOpTimeCallback(response, onCompletionGuard);
+        },
+        ReadPreferenceSetting::secondaryPreferredMetadata(),
+        RemoteCommandRequest::kNoTimeout /* find network timeout */,
+        RemoteCommandRequest::kNoTimeout /* getMore network timeout */,
+        RemoteCommandRetryScheduler::makeRetryPolicy(
+            numInitialSyncOplogFindAttempts.load(),
+            executor::RemoteCommandRequest::kNoTimeout,
+            RemoteCommandRetryScheduler::kAllRetriableErrors));
+    Status scheduleStatus = _beginFetchingOpTimeFetcher->schedule();
+    if (!scheduleStatus.isOK()) {
+        _beginFetchingOpTimeFetcher.reset();
+    }
+    return scheduleStatus;
 }
 
 void InitialSyncer::_rollbackCheckerResetCallback(
@@ -679,24 +704,42 @@ void InitialSyncer::_rollbackCheckerResetCallback(
 }
 
 void InitialSyncer::_getBeginFetchingOpTimeCallback(
-    const executor::TaskExecutor::ResponseStatus& response,
+    const StatusWith<Fetcher::QueryResponse>& result,
     std::shared_ptr<OnCompletionGuard> onCompletionGuard) {
     stdx::unique_lock<stdx::mutex> lock(_mutex);
     auto status = _checkForShutdownAndConvertStatus_inlock(
-        response.status,
+        result.getStatus(),
         "error while getting oldest active transaction timestamp for begin fetching timestamp");
     if (!status.isOK()) {
         onCompletionGuard->setResultAndCancelRemainingWork_inlock(lock, status);
         return;
     }
 
-    invariant(response.data.hasField("transactions"));
+    const auto docs = result.getValue().documents;
+    if (docs.size() > 1) {
+        onCompletionGuard->setResultAndCancelRemainingWork_inlock(
+            lock,
+            Status(ErrorCodes::TooManyMatchingDocuments,
+                   str::stream() << "Expected to receive one document for the oldest active "
+                                    "transaction entry, but received: "
+                                 << docs.size()
+                                 << ". First: "
+                                 << redact(docs.front())
+                                 << ". Last: "
+                                 << redact(docs.back())));
+        return;
+    }
 
-    // Only set beginFetchingOpTime if the oldestActiveOplogEntryTimestamp actually exists.
+    // Only set beginFetchingOpTime if the oldestActiveOplogEntryOpTime actually exists.
     OpTime beginFetchingOpTime = OpTime();
-    if (response.data["transactions"].embeddedObject().hasField("oldestActiveOplogEntryOpTime")) {
-        beginFetchingOpTime = repl::OpTime::parse(
-            response.data["transactions"]["oldestActiveOplogEntryOpTime"].Obj());
+    if (docs.size() != 0) {
+        auto entry = SessionTxnRecord::parse(
+            IDLParserErrorContext("oldest active transaction optime for initial sync"),
+            docs.front());
+        auto optime = entry.getStartOpTime();
+        if (optime) {
+            beginFetchingOpTime = optime.get();
+        }
     }
 
     status = _scheduleLastOplogEntryFetcher_inlock(
@@ -788,7 +831,8 @@ void InitialSyncer::_fcvFetcherCallback(const StatusWith<Fetcher::QueryResponse>
         onCompletionGuard->setResultAndCancelRemainingWork_inlock(
             lock,
             Status(ErrorCodes::TooManyMatchingDocuments,
-                   str::stream() << "Expected to receive one document, but received: "
+                   str::stream() << "Expected to receive one feature compatibility version "
+                                    "document, but received: "
                                  << docs.size()
                                  << ". First: "
                                  << redact(docs.front())
diff --git a/src/mongo/db/repl/initial_syncer.h b/src/mongo/db/repl/initial_syncer.h
index 31c4790feb7..75c417789dd 100644
--- a/src/mongo/db/repl/initial_syncer.h
+++ b/src/mongo/db/repl/initial_syncer.h
@@ -302,7 +302,7 @@ private:
      *         |
      *         |
      *         V
-     *   _getBeginFetchingTimestampCallback()
+     *   _getBeginFetchingOpTimeCallback()
      *         |
      *         |
      *         V
@@ -420,7 +420,7 @@ private:
      * serverStatus response, which refers to the optime of the oldest active transaction with an
      * oplog entry. It will be used as the beginFetchingTimestamp.
      */
-    void _getBeginFetchingOpTimeCallback(const executor::TaskExecutor::ResponseStatus& response,
+    void _getBeginFetchingOpTimeCallback(const StatusWith<Fetcher::QueryResponse>& result,
                                          std::shared_ptr<OnCompletionGuard> onCompletionGuard);
 
     /**
@@ -643,17 +643,18 @@ private:
     // Handle to currently scheduled _getNextApplierBatchCallback() task.
     executor::TaskExecutor::CallbackHandle _getNextApplierBatchHandle;  // (M)
 
-    std::unique_ptr<InitialSyncState> _initialSyncState;  // (M)
-    std::unique_ptr<OplogFetcher> _oplogFetcher;          // (S)
-    std::unique_ptr<Fetcher> _lastOplogEntryFetcher;      // (S)
-    std::unique_ptr<Fetcher> _fCVFetcher;                 // (S)
-    std::unique_ptr<MultiApplier> _applier;               // (M)
-    HostAndPort _syncSource;                              // (M)
-    OpTime _lastFetched;                                  // (MX)
-    OpTimeAndWallTime _lastApplied;                       // (MX)
-    std::unique_ptr<OplogBuffer> _oplogBuffer;            // (M)
-    std::unique_ptr<OplogApplier::Observer> _observer;    // (S)
-    std::unique_ptr<OplogApplier> _oplogApplier;          // (M)
+    std::unique_ptr<InitialSyncState> _initialSyncState;   // (M)
+    std::unique_ptr<OplogFetcher> _oplogFetcher;           // (S)
+    std::unique_ptr<Fetcher> _beginFetchingOpTimeFetcher;  // (S)
+    std::unique_ptr<Fetcher> _lastOplogEntryFetcher;       // (S)
+    std::unique_ptr<Fetcher> _fCVFetcher;                  // (S)
+    std::unique_ptr<MultiApplier> _applier;                // (M)
+    HostAndPort _syncSource;                               // (M)
+    OpTime _lastFetched;                                   // (MX)
+    OpTimeAndWallTime _lastApplied;                        // (MX)
+    std::unique_ptr<OplogBuffer> _oplogBuffer;             // (M)
+    std::unique_ptr<OplogApplier::Observer> _observer;     // (S)
+    std::unique_ptr<OplogApplier> _oplogApplier;           // (M)
 
     // Used to signal changes in _state.
     mutable stdx::condition_variable _stateCondition;
diff --git a/src/mongo/db/repl/initial_syncer_test.cpp b/src/mongo/db/repl/initial_syncer_test.cpp
index 48b134eda45..ca111c8c9a1 100644
--- a/src/mongo/db/repl/initial_syncer_test.cpp
+++ b/src/mongo/db/repl/initial_syncer_test.cpp
@@ -510,14 +510,6 @@ BSONObj makeRollbackCheckerResponse(int rollbackId) {
 }
 
 /**
- * Generates a serverStatus response with an 'oldestActiveOplogEntryOpTime' field.
- */
-BSONObj makeServerStatusResponse(OpTime oldestActiveTxnOpTime) {
-    return BSON("ok" << 1 << "transactions"
-                     << BSON("oldestActiveOplogEntryOpTime" << oldestActiveTxnOpTime));
-}
-
-/**
  * Generates a cursor response for a Fetcher to consume.
  */
 RemoteCommandResponse makeCursorResponse(CursorId cursorId,
@@ -1170,19 +1162,21 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughRollbackCheckerCallbackError
     ASSERT_EQUALS(ErrorCodes::OperationFailed, _lastApplied);
 }
 
-TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingTimestampScheduleError) {
+TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingOpTimeScheduleError) {
     auto initialSyncer = &getInitialSyncer();
     auto opCtx = makeOpCtx();
 
-    // Getting the begin fetching timestamp is the only time a serverStatus command is sent, so we
-    // reject the serverStatus command and save the request for inspection at the end of this test
-    // case.
+    // We reject the 'find' command for the begin fetching optime and save the request for
+    // inspection at the end of this test case.
     executor::RemoteCommandRequest request;
-    _executorProxy->shouldFailScheduleRemoteCommandRequest =
-        [&request](const executor::RemoteCommandRequest& requestToSend) {
-            request = requestToSend;
-            return "serverStatus" == requestToSend.cmdObj.firstElement().fieldNameStringData();
-        };
+    _executorProxy->shouldFailScheduleRemoteCommandRequest = [&request](
+        const executor::RemoteCommandRequest& requestToSend) {
+        request = requestToSend;
+        auto elem = requestToSend.cmdObj.firstElement();
+        return (
+            ("find" == elem.fieldNameStringData()) &&
+            (NamespaceString::kSessionTransactionsTableNamespace.coll() == elem.valueStringData()));
+    };
 
     HostAndPort syncSource("localhost", 12345);
     _syncSourceSelector->setChooseNewSyncSourceResult_forTest(syncSource);
@@ -1201,11 +1195,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingTimestampSch
     ASSERT_EQUALS(ErrorCodes::OperationFailed, _lastApplied);
 
     ASSERT_EQUALS(syncSource, request.target);
-    ASSERT_EQUALS(NamespaceString::kAdminDb, request.dbname);
-    assertRemoteCommandNameEquals("serverStatus", request);
+    ASSERT_EQUALS(NamespaceString::kConfigDb, request.dbname);
+    assertRemoteCommandNameEquals("find", request);
 }
 
-TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingTimestampCallbackError) {
+TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingOpTimeCallbackError) {
     auto initialSyncer = &getInitialSyncer();
     auto opCtx = makeOpCtx();
 
@@ -1221,9 +1215,9 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingTimestampCal
         net->runReadyNetworkOperations();
 
         assertRemoteCommandNameEquals(
-            "serverStatus",
+            "find",
             net->scheduleErrorResponse(
-                Status(ErrorCodes::OperationFailed, "serverStatus command failed at sync source")));
+                Status(ErrorCodes::OperationFailed, "find command failed at sync source")));
         net->runReadyNetworkOperations();
     }
 
@@ -1231,18 +1225,46 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetBeginFetchingTimestampCal
     ASSERT_EQUALS(ErrorCodes::OperationFailed, _lastApplied);
 }
 
+TEST_F(InitialSyncerTest, InitialSyncerCancelsBeginFetchingOpTimeFetcherOnShutdown) {
+    auto initialSyncer = &getInitialSyncer();
+    auto opCtx = makeOpCtx();
+
+    _syncSourceSelector->setChooseNewSyncSourceResult_forTest(HostAndPort("localhost", 12345));
+    ASSERT_OK(initialSyncer->startup(opCtx.get(), maxAttempts));
+
+    auto net = getNet();
+    {
+        executor::NetworkInterfaceMock::InNetworkGuard guard(net);
+
+        // Base rollback ID.
+        net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
+
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+    }
+
+    ASSERT_OK(initialSyncer->shutdown());
+    executor::NetworkInterfaceMock::InNetworkGuard(net)->runReadyNetworkOperations();
+
+    initialSyncer->join();
+    ASSERT_EQUALS(ErrorCodes::CallbackCanceled, _lastApplied.getStatus());
+}
+
 TEST_F(InitialSyncerTest, InitialSyncerPassesThroughLastOplogEntryFetcherScheduleError) {
     auto initialSyncer = &getInitialSyncer();
     auto opCtx = makeOpCtx();
 
-    // The last oplog entry fetcher is the first component that sends a find command so we reject
-    // any find commands and save the request for inspection at the end of this test case.
+    // We reject the 'find' command on the oplog and save the request for inspection at the end of
+    // this test case.
     executor::RemoteCommandRequest request;
-    _executorProxy->shouldFailScheduleRemoteCommandRequest =
-        [&request](const executor::RemoteCommandRequest& requestToSend) {
-            request = requestToSend;
-            return "find" == requestToSend.cmdObj.firstElement().fieldNameStringData();
-        };
+    _executorProxy->shouldFailScheduleRemoteCommandRequest = [&request](
+        const executor::RemoteCommandRequest& requestToSend) {
+        request = requestToSend;
+        auto elem = requestToSend.cmdObj.firstElement();
+        return (("find" == elem.fieldNameStringData()) && ("oplog.rs" == elem.valueStringData()));
+    };
 
     HostAndPort syncSource("localhost", 12345);
     _syncSourceSelector->setChooseNewSyncSourceResult_forTest(syncSource);
@@ -1255,10 +1277,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughLastOplogEntryFetcherSchedul
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
     }
 
@@ -1286,10 +1309,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughLastOplogEntryFetcherCallbac
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         assertRemoteCommandNameEquals(
@@ -1317,10 +1341,11 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsLastOplogEntryFetcherOnShutdown) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         ASSERT_TRUE(net->hasReadyRequests());
@@ -1348,10 +1373,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1376,10 +1402,11 @@ TEST_F(InitialSyncerTest,
     // Base rollback ID.
     net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-    // Send an empty optime as the response to the serverStatus request, which will cause the
-    // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-    auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-    assertRemoteCommandNameEquals("serverStatus", request);
+    // Send an empty optime as the response to the beginFetchingOptime find request, which will
+    // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+    auto request = net->scheduleSuccessfulResponse(
+        makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+    assertRemoteCommandNameEquals("find", request);
     net->runReadyNetworkOperations();
 
     // Last oplog entry first attempt - retriable error.
@@ -1409,10 +1436,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1440,10 +1468,10 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1482,10 +1510,10 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughFCVFetcherScheduleError) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1513,10 +1541,10 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughFCVFetcherCallbackError) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1548,10 +1576,10 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsFCVFetcherOnShutdown) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1580,10 +1608,11 @@ TEST_F(InitialSyncerTest, InitialSyncerResendsFindCommandIfFCVFetcherReturnsRetr
     // Base rollback ID.
     net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-    // Send an empty optime as the response to the serverStatus request, which will cause the
-    // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-    auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-    assertRemoteCommandNameEquals("serverStatus", request);
+    // Send an empty optime as the response to the beginFetchingOptime find request, which will
+    // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+    auto request = net->scheduleSuccessfulResponse(
+        makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+    assertRemoteCommandNameEquals("find", request);
     net->runReadyNetworkOperations();
 
     // Last oplog entry.
@@ -1616,10 +1645,11 @@ void InitialSyncerTest::runInitialSyncWithBadFCVResponse(std::vector<BSONObj> do
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1684,10 +1714,11 @@ TEST_F(InitialSyncerTest, InitialSyncerSucceedsWhenFCVFetcherReturnsOldVersion)
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1735,10 +1766,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughOplogFetcherScheduleError) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1777,10 +1809,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughOplogFetcherCallbackError) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1827,10 +1860,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1889,10 +1923,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -1949,10 +1984,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2014,10 +2050,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2059,10 +2096,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2101,10 +2139,11 @@ TEST_F(InitialSyncerTest, InitialSyncerIgnoresLocalDatabasesWhenCloningDatabases
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2169,10 +2208,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2243,10 +2283,11 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsBothOplogFetcherAndDatabasesCloner
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2274,9 +2315,10 @@ TEST_F(InitialSyncerTest,
     bool first = true;
     _executorProxy->shouldFailScheduleRemoteCommandRequest =
         [&first, &request](const executor::RemoteCommandRequest& requestToSend) {
-            if ("find" == requestToSend.cmdObj.firstElement().fieldNameStringData() &&
-                requestToSend.cmdObj.hasField("sort") &&
-                1 == requestToSend.cmdObj.getIntField("limit")) {
+            auto elem = requestToSend.cmdObj.firstElement();
+            if (("find" == elem.fieldNameStringData()) && (requestToSend.cmdObj.hasField("sort")) &&
+                (1 == requestToSend.cmdObj.getIntField("limit")) &&
+                (NamespaceString::kRsOplogNamespace.coll().toString() == elem.valueStringData())) {
                 if (first) {
                     first = false;
                     return false;
@@ -2297,10 +2339,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2341,10 +2384,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2401,10 +2445,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2456,10 +2501,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2522,10 +2568,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2580,10 +2627,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2651,10 +2699,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2725,10 +2774,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2799,10 +2849,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2855,10 +2906,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2916,10 +2968,11 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsLastRollbackCheckerOnShutdown) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -2978,10 +3031,11 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsLastRollbackCheckerOnOplogFetcherC
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(1));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3045,10 +3099,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3103,10 +3158,11 @@ TEST_F(InitialSyncerTest, LastOpTimeShouldBeSetEvenIfNoOperationsAreAppliedAfter
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3196,10 +3252,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetNextApplierBatchScheduleE
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3258,10 +3315,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughSecondGetNextApplierBatchSch
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3320,10 +3378,11 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsGetNextApplierBatchOnShutdown) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3384,10 +3443,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughGetNextApplierBatchInLockErr
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3456,10 +3516,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3519,10 +3580,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughMultiApplierScheduleError) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3598,10 +3660,11 @@ TEST_F(InitialSyncerTest, InitialSyncerPassesThroughMultiApplierCallbackError) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3652,10 +3715,11 @@ TEST_F(InitialSyncerTest, InitialSyncerCancelsGetNextApplierBatchCallbackOnOplog
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3712,10 +3776,11 @@ OplogEntry InitialSyncerTest::doInitialSyncWithOneBatch(bool shouldSetFCV) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3811,10 +3876,11 @@ TEST_F(InitialSyncerTest,
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -3931,10 +3997,11 @@ TEST_F(
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -4029,10 +4096,11 @@ TEST_F(InitialSyncerTest, OplogOutOfOrderOnOplogFetchFinish) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -4092,10 +4160,11 @@ TEST_F(InitialSyncerTest, GetInitialSyncProgressReturnsCorrectProgress) {
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -4143,13 +4212,15 @@ TEST_F(InitialSyncerTest, GetInitialSyncProgressReturnsCorrectProgress) {
         ASSERT_EQUALS(when, net->runUntil(when));
 
         // Base rollback ID.
-        auto request = net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
-        assertRemoteCommandNameEquals("replSetGetRBID", request);
+        auto rbidRequest =
+            net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
+        assertRemoteCommandNameEquals("replSetGetRBID", rbidRequest);
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto findRequest = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", findRequest);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.
@@ -4364,10 +4435,11 @@ TEST_F(InitialSyncerTest, GetInitialSyncProgressOmitsClonerStatsIfClonerStatsExc
         // Base rollback ID.
         net->scheduleSuccessfulResponse(makeRollbackCheckerResponse(baseRollbackId));
 
-        // Send an empty optime as the response to the serverStatus request, which will cause the
-        // beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
-        auto request = net->scheduleSuccessfulResponse(makeServerStatusResponse(OpTime()));
-        assertRemoteCommandNameEquals("serverStatus", request);
+        // Send an empty optime as the response to the beginFetchingOptime find request, which will
+        // cause the beginFetchingTimestamp to be the same as the beginApplyingTimestamp.
+        auto request = net->scheduleSuccessfulResponse(
+            makeCursorResponse(0LL, NamespaceString::kSessionTransactionsTableNamespace, {}, true));
+        assertRemoteCommandNameEquals("find", request);
         net->runReadyNetworkOperations();
 
         // Last oplog entry.