Revert "SERVER-26520 CollectionCloner fetches document count for progress tracking from sync source before copying documents"

This reverts commit 44957419b2dd4e6b3f7be8b817a7fcd8c71d643d.

9 files changed, 76 insertions, 380 deletions

diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index d92b0575b0a..8eec05c66a1 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -760,7 +760,10 @@ env.Library(
     ],
     LIBDEPS=[
         'replmocks',
+        '$BUILD_DIR/mongo/db/auth/authorization_manager_mock_init',
+        '$BUILD_DIR/mongo/db/commands_test_crutch',
         '$BUILD_DIR/mongo/executor/thread_pool_task_executor_test_fixture',
+        '$BUILD_DIR/mongo/db/service_context_noop_init',
     ],
 )
 
@@ -773,11 +776,9 @@ env.Library(
         'task_runner',
         '$BUILD_DIR/mongo/base',
         '$BUILD_DIR/mongo/client/fetcher',
-        '$BUILD_DIR/mongo/client/remote_command_retry_scheduler',
         '$BUILD_DIR/mongo/db/catalog/collection_options',
         '$BUILD_DIR/mongo/db/catalog/document_validation',
         '$BUILD_DIR/mongo/executor/task_executor_interface',
-        '$BUILD_DIR/mongo/rpc/command_status',
         '$BUILD_DIR/mongo/util/progress_meter',
     ],
 )
@@ -788,10 +789,6 @@ env.CppUnitTest(
     LIBDEPS=[
         'collection_cloner',
         'base_cloner_test_fixture',
-        '$BUILD_DIR/mongo/db/auth/authorization_manager_mock_init',
-        '$BUILD_DIR/mongo/db/commands_test_crutch',
-        '$BUILD_DIR/mongo/db/service_context_noop_init',
-        '$BUILD_DIR/mongo/unittest/task_executor_proxy',
     ],
 )
 
@@ -813,9 +810,6 @@ env.CppUnitTest(
     LIBDEPS=[
         'database_cloner',
         'base_cloner_test_fixture',
-        '$BUILD_DIR/mongo/db/auth/authorization_manager_mock_init',
-        '$BUILD_DIR/mongo/db/commands_test_crutch',
-        '$BUILD_DIR/mongo/db/service_context_noop_init',
     ],
 )
 
@@ -1010,7 +1004,6 @@ env.CppUnitTest(
         'data_replicator_test.cpp',
     ],
     LIBDEPS=[
-        'base_cloner_test_fixture',
         'data_replicator',
         'data_replicator_external_state_mock',
         'replication_executor_test_fixture',
diff --git a/src/mongo/db/repl/base_cloner_test_fixture.cpp b/src/mongo/db/repl/base_cloner_test_fixture.cpp
index 59c8ff3c0f0..399be148782 100644
--- a/src/mongo/db/repl/base_cloner_test_fixture.cpp
+++ b/src/mongo/db/repl/base_cloner_test_fixture.cpp
@@ -50,11 +50,6 @@ const BSONObj BaseClonerTest::idIndexSpec = BSON("v" << 1 << "key" << BSON("_id"
                                                      << nss.ns());
 
 // static
-BSONObj BaseClonerTest::createCountResponse(int documentCount) {
-    return BSON("n" << documentCount << "ok" << 1);
-}
-
-// static
 BSONObj BaseClonerTest::createCursorResponse(CursorId cursorId,
                                              const std::string& ns,
                                              const BSONArray& docs,
diff --git a/src/mongo/db/repl/base_cloner_test_fixture.h b/src/mongo/db/repl/base_cloner_test_fixture.h
index fb8ecf22861..66943f15214 100644
--- a/src/mongo/db/repl/base_cloner_test_fixture.h
+++ b/src/mongo/db/repl/base_cloner_test_fixture.h
@@ -58,11 +58,6 @@ public:
     typedef executor::NetworkInterfaceMock::NetworkOperationIterator NetworkOperationIterator;
 
     /**
-     * Creates a count response with given document count.
-     */
-    static BSONObj createCountResponse(int documentCount);
-
-    /**
      * Creates a cursor response with given array of documents.
      */
     static BSONObj createCursorResponse(CursorId cursorId,
diff --git a/src/mongo/db/repl/collection_cloner.cpp b/src/mongo/db/repl/collection_cloner.cpp
index aeb2f61da63..1db815a789f 100644
--- a/src/mongo/db/repl/collection_cloner.cpp
+++ b/src/mongo/db/repl/collection_cloner.cpp
@@ -32,15 +32,12 @@
 
 #include "mongo/db/repl/collection_cloner.h"
 
-#include "mongo/base/string_data.h"
-#include "mongo/bson/util/bson_extract.h"
 #include "mongo/client/remote_command_retry_scheduler.h"
 #include "mongo/db/catalog/collection_options.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/repl/storage_interface.h"
 #include "mongo/db/repl/storage_interface_mock.h"
 #include "mongo/db/server_parameters.h"
-#include "mongo/rpc/get_status_from_command_result.h"
 #include "mongo/util/assert_util.h"
 #include "mongo/util/destructor_guard.h"
 #include "mongo/util/log.h"
@@ -53,16 +50,12 @@ namespace {
 using LockGuard = stdx::lock_guard<stdx::mutex>;
 using UniqueLock = stdx::unique_lock<stdx::mutex>;
 
-constexpr auto kCountResponseDocumentCountFieldName = "n"_sd;
-
 const int kProgressMeterSecondsBetween = 60;
 const int kProgressMeterCheckInterval = 128;
 
 // The batchSize to use for the query to get all documents from the collection.
 // 16MB max batch size / 12 byte min doc size * 10 (for good measure) = batchSize to use.
 const auto batchSize = (16 * 1024 * 1024) / 12 * 10;
-// The number of attempts for the count command, which gets the document count.
-MONGO_EXPORT_SERVER_PARAMETER(numInitialSyncCollectionCountAttempts, int, 3);
 // The number of attempts for the listIndexes commands.
 MONGO_EXPORT_SERVER_PARAMETER(numInitialSyncListIndexesAttempts, int, 3);
 // The number of attempts for the find command, which gets the data.
@@ -85,18 +78,6 @@ CollectionCloner::CollectionCloner(executor::TaskExecutor* executor,
       _onCompletion(onCompletion),
       _storageInterface(storageInterface),
       _active(false),
-      _countScheduler(_executor,
-                      RemoteCommandRequest(_source,
-                                           _sourceNss.db().toString(),
-                                           BSON("count" << _sourceNss.coll()),
-                                           rpc::ServerSelectionMetadata(true, boost::none).toBSON(),
-                                           nullptr,
-                                           RemoteCommandRequest::kNoTimeout),
-                      stdx::bind(&CollectionCloner::_countCallback, this, stdx::placeholders::_1),
-                      RemoteCommandRetryScheduler::makeRetryPolicy(
-                          numInitialSyncCollectionCountAttempts,
-                          executor::RemoteCommandRequest::kNoTimeout,
-                          RemoteCommandRetryScheduler::kAllRetriableErrors)),
       _listIndexesFetcher(_executor,
                           _source,
                           _sourceNss.db().toString(),
@@ -143,7 +124,7 @@ CollectionCloner::CollectionCloner(executor::TaskExecutor* executor,
           _dbWorkTaskRunner.schedule(task);
           return executor::TaskExecutor::CallbackHandle();
       }),
-      _progressMeter(1U,  // total will be replaced with count command result.
+      _progressMeter(1U,
                      kProgressMeterSecondsBetween,
                      kProgressMeterCheckInterval,
                      "documents copied",
@@ -157,6 +138,10 @@ CollectionCloner::CollectionCloner(executor::TaskExecutor* executor,
     uassert(ErrorCodes::BadValue, "callback function cannot be null", onCompletion);
     uassert(ErrorCodes::BadValue, "storage interface cannot be null", storageInterface);
     _stats.ns = _sourceNss.ns();
+    // Hide collection size in progress output because this information is not available.
+    // Additionally, even if the collection size is known, it may change while we are copying the
+    // documents from the sync source.
+    _progressMeter.showTotal(false);
 }
 
 CollectionCloner::~CollectionCloner() {
@@ -196,7 +181,7 @@ Status CollectionCloner::startup() {
     }
 
     _stats.start = _executor->now();
-    Status scheduleResult = _countScheduler.startup();
+    Status scheduleResult = _listIndexesFetcher.schedule();
     if (!scheduleResult.isOK()) {
         return scheduleResult;
     }
@@ -211,7 +196,6 @@ void CollectionCloner::shutdown() {
         return;
     }
 
-    _countScheduler.shutdown();
     _listIndexesFetcher.shutdown();
     _findFetcher.shutdown();
     _dbWorkTaskRunner.cancel();
@@ -239,75 +223,6 @@ void CollectionCloner::setScheduleDbWorkFn_forTest(const ScheduleDbWorkFn& sched
     _scheduleDbWorkFn = scheduleDbWorkFn;
 }
 
-void CollectionCloner::_countCallback(
-    const executor::TaskExecutor::RemoteCommandCallbackArgs& args) {
-
-    // No need to reword status reason in the case of cancellation.
-    if (ErrorCodes::CallbackCanceled == args.response.status) {
-        _finishCallback(args.response.status);
-        return;
-    }
-
-    if (!args.response.status.isOK()) {
-        _finishCallback({args.response.status.code(),
-                         str::stream() << "During count call on collection '" << _sourceNss.ns()
-                                       << "' from "
-                                       << _source.toString()
-                                       << ", there was an error '"
-                                       << args.response.status.reason()
-                                       << "'"});
-        return;
-    }
-
-    Status commandStatus = getStatusFromCommandResult(args.response.data);
-    if (!commandStatus.isOK()) {
-        _finishCallback({commandStatus.code(),
-                         str::stream() << "During count call on collection '" << _sourceNss.ns()
-                                       << "' from "
-                                       << _source.toString()
-                                       << ", there was a command error '"
-                                       << commandStatus.reason()
-                                       << "'"});
-        return;
-    }
-
-    long long count = 0;
-    auto countStatus =
-        bsonExtractIntegerField(args.response.data, kCountResponseDocumentCountFieldName, &count);
-    if (!countStatus.isOK()) {
-        _finishCallback({countStatus.code(),
-                         str::stream() << "There was an error parsing document count from count "
-                                          "command result on collection "
-                                       << _sourceNss.ns()
-                                       << " from "
-                                       << _source.toString()
-                                       << ": "
-                                       << countStatus.reason()});
-        return;
-    }
-
-    if (count < 0) {
-        _finishCallback({ErrorCodes::BadValue,
-                         str::stream() << "Count call on collection " << _sourceNss.ns() << " from "
-                                       << _source.toString()
-                                       << " returned negative document count: "
-                                       << count});
-        return;
-    }
-
-    {
-        LockGuard lk(_mutex);
-        _stats.documentToCopy = count;
-        _progressMeter.setTotalWhileRunning(static_cast<unsigned long long>(count));
-    }
-
-    auto scheduleStatus = _listIndexesFetcher.schedule();
-    if (!scheduleStatus.isOK()) {
-        _finishCallback(scheduleStatus);
-        return;
-    }
-}
-
 void CollectionCloner::_listIndexesCallback(const Fetcher::QueryResponseStatus& fetchResult,
                                             Fetcher::NextAction* nextAction,
                                             BSONObjBuilder* getMoreBob) {
@@ -479,7 +394,7 @@ void CollectionCloner::_insertDocumentsCallback(const executor::TaskExecutor::Ca
     }
 
     _documents.swap(docs);
-    _stats.documentsCopied += docs.size();
+    _stats.documents += docs.size();
     ++_stats.fetchBatches;
     _progressMeter.hit(int(docs.size()));
     invariant(_collLoader);
@@ -529,8 +444,6 @@ void CollectionCloner::_finishCallback(const Status& status) {
     LOG(1) << "    collection: " << _destNss << ", stats: " << _stats.toString();
 }
 
-constexpr StringData CollectionCloner::Stats::kDocumentsToCopyFieldName;
-constexpr StringData CollectionCloner::Stats::kDocumentsCopiedFieldName;
 
 std::string CollectionCloner::Stats::toString() const {
     return toBSON().toString();
@@ -544,8 +457,7 @@ BSONObj CollectionCloner::Stats::toBSON() const {
 }
 
 void CollectionCloner::Stats::append(BSONObjBuilder* builder) const {
-    builder->appendNumber(kDocumentsToCopyFieldName, documentToCopy);
-    builder->appendNumber(kDocumentsCopiedFieldName, documentsCopied);
+    builder->appendNumber("documents", documents);
     builder->appendNumber("indexes", indexes);
     builder->appendNumber("fetchedBatches", fetchBatches);
     if (start != Date_t()) {
diff --git a/src/mongo/db/repl/collection_cloner.h b/src/mongo/db/repl/collection_cloner.h
index 005156a55a9..fd6e4527b0f 100644
--- a/src/mongo/db/repl/collection_cloner.h
+++ b/src/mongo/db/repl/collection_cloner.h
@@ -34,10 +34,8 @@
 
 #include "mongo/base/disallow_copying.h"
 #include "mongo/base/status.h"
-#include "mongo/base/string_data.h"
 #include "mongo/bson/bsonobj.h"
 #include "mongo/client/fetcher.h"
-#include "mongo/client/remote_command_retry_scheduler.h"
 #include "mongo/db/catalog/collection_options.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/repl/base_cloner.h"
@@ -64,14 +62,10 @@ class CollectionCloner : public BaseCloner {
 
 public:
     struct Stats {
-        static constexpr StringData kDocumentsToCopyFieldName = "documentsToCopy"_sd;
-        static constexpr StringData kDocumentsCopiedFieldName = "documentsCopied"_sd;
-
         std::string ns;
         Date_t start;
         Date_t end;
-        size_t documentToCopy{0};
-        size_t documentsCopied{0};
+        size_t documents{0};
         size_t indexes{0};
         size_t fetchBatches{0};
 
@@ -141,11 +135,6 @@ public:
 
 private:
     /**
-     * Read number of documents in collection from count result.
-     */
-    void _countCallback(const executor::TaskExecutor::RemoteCommandCallbackArgs& args);
-
-    /**
      * Read index specs from listIndexes result.
      */
     void _listIndexesCallback(const StatusWith<Fetcher::QueryResponse>& fetchResult,
@@ -208,13 +197,12 @@ private:
     CallbackFn _onCompletion;             // (R) Invoked once when cloning completes or fails.
     StorageInterface* _storageInterface;  // (R) Not owned by us.
     bool _active;                         // (M) true when Collection Cloner is started.
-    RemoteCommandRetryScheduler _countScheduler;  // (S)
-    Fetcher _listIndexesFetcher;                  // (S)
-    Fetcher _findFetcher;                         // (S)
-    std::vector<BSONObj> _indexSpecs;             // (M)
-    BSONObj _idIndexSpec;                         // (M)
-    std::vector<BSONObj> _documents;              // (M) Documents read from fetcher to insert.
-    TaskRunner _dbWorkTaskRunner;                 // (R)
+    Fetcher _listIndexesFetcher;          // (S)
+    Fetcher _findFetcher;                 // (S)
+    std::vector<BSONObj> _indexSpecs;     // (M)
+    BSONObj _idIndexSpec;                 // (M)
+    std::vector<BSONObj> _documents;      // (M) Documents read from fetcher to insert.
+    TaskRunner _dbWorkTaskRunner;         // (R)
     ScheduleDbWorkFn
         _scheduleDbWorkFn;         // (RT) Function for scheduling database work using the executor.
     Stats _stats;                  // (M) stats for this instance.
diff --git a/src/mongo/db/repl/collection_cloner_test.cpp b/src/mongo/db/repl/collection_cloner_test.cpp
index 3e87c8be2b2..6c31428d2bd 100644
--- a/src/mongo/db/repl/collection_cloner_test.cpp
+++ b/src/mongo/db/repl/collection_cloner_test.cpp
@@ -37,7 +37,6 @@
 #include "mongo/db/repl/storage_interface.h"
 #include "mongo/db/repl/storage_interface_mock.h"
 #include "mongo/stdx/memory.h"
-#include "mongo/unittest/task_executor_proxy.h"
 #include "mongo/unittest/unittest.h"
 #include "mongo/util/mongoutils/str.h"
 
@@ -179,146 +178,12 @@ TEST_F(CollectionClonerTest, FirstRemoteCommand) {
     NetworkOperationIterator noi = net->getNextReadyRequest();
     auto&& noiRequest = noi->getRequest();
     ASSERT_EQUALS(nss.db().toString(), noiRequest.dbname);
-    ASSERT_EQUALS("count", std::string(noiRequest.cmdObj.firstElementFieldName()));
+    ASSERT_EQUALS("listIndexes", std::string(noiRequest.cmdObj.firstElementFieldName()));
     ASSERT_EQUALS(nss.coll().toString(), noiRequest.cmdObj.firstElement().valuestrsafe());
     ASSERT_FALSE(net->hasReadyRequests());
     ASSERT_TRUE(collectionCloner->isActive());
 }
 
-TEST_F(CollectionClonerTest, CollectionClonerSetsDocumentCountInStatsFromCountCommandResult) {
-    ASSERT_OK(collectionCloner->startup());
-
-    ASSERT_EQUALS(0U, collectionCloner->getStats().documentToCopy);
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(100));
-    }
-    getExecutor().shutdown();
-    collectionCloner->join();
-    ASSERT_EQUALS(100U, collectionCloner->getStats().documentToCopy);
-}
-
-TEST_F(CollectionClonerTest, CollectionClonerPassesThroughNonRetriableErrorFromCountCommand) {
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(ErrorCodes::OperationFailed, "");
-    }
-    collectionCloner->join();
-    ASSERT_EQUALS(ErrorCodes::OperationFailed, getStatus());
-}
-
-TEST_F(CollectionClonerTest, CollectionClonerPassesThroughCommandStatusErrorFromCountCommand) {
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(BSON("ok" << 0 << "errmsg"
-                                         << "count error"
-                                         << "code"
-                                         << int(ErrorCodes::OperationFailed)));
-    }
-    collectionCloner->join();
-    ASSERT_EQUALS(ErrorCodes::OperationFailed, getStatus());
-    ASSERT_STRING_CONTAINS(getStatus().reason(), "count error");
-}
-
-TEST_F(CollectionClonerTest, CollectionClonerResendsCountCommandOnRetriableError) {
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(ErrorCodes::HostNotFound, "");
-        processNetworkResponse(ErrorCodes::NetworkTimeout, "");
-        processNetworkResponse(createCountResponse(100));
-    }
-    getExecutor().shutdown();
-    collectionCloner->join();
-    ASSERT_EQUALS(100U, collectionCloner->getStats().documentToCopy);
-}
-
-TEST_F(CollectionClonerTest, CollectionClonerReturnsLastRetriableErrorOnExceedingCountAttempts) {
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(ErrorCodes::HostNotFound, "");
-        processNetworkResponse(ErrorCodes::NetworkTimeout, "");
-        processNetworkResponse(ErrorCodes::NotMaster, "");
-    }
-    collectionCloner->join();
-    ASSERT_EQUALS(ErrorCodes::NotMaster, getStatus());
-}
-
-TEST_F(CollectionClonerTest, CollectionClonerReturnsNoSuchKeyOnMissingDocumentCountFieldName) {
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(BSON("ok" << 1));
-    }
-    collectionCloner->join();
-    ASSERT_EQUALS(ErrorCodes::NoSuchKey, getStatus());
-}
-
-TEST_F(CollectionClonerTest, CollectionClonerReturnsBadValueOnNegativeDocumentCount) {
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(-1));
-    }
-    collectionCloner->join();
-    ASSERT_EQUALS(ErrorCodes::BadValue, getStatus());
-}
-
-class TaskExecutorWithFailureInScheduleRemoteCommand : public unittest::TaskExecutorProxy {
-public:
-    using ShouldFailRequestFn = stdx::function<bool(const executor::RemoteCommandRequest&)>;
-
-    TaskExecutorWithFailureInScheduleRemoteCommand(executor::TaskExecutor* executor,
-                                                   ShouldFailRequestFn shouldFailRequest)
-        : unittest::TaskExecutorProxy(executor), _shouldFailRequest(shouldFailRequest) {}
-
-    StatusWith<CallbackHandle> scheduleRemoteCommand(const executor::RemoteCommandRequest& request,
-                                                     const RemoteCommandCallbackFn& cb) override {
-        if (_shouldFailRequest(request)) {
-            return Status(ErrorCodes::OperationFailed, "failed to schedule remote command");
-        }
-        return getExecutor()->scheduleRemoteCommand(request, cb);
-    }
-
-private:
-    ShouldFailRequestFn _shouldFailRequest;
-};
-
-TEST_F(CollectionClonerTest,
-       CollectionClonerReturnsScheduleErrorOnFailingToScheduleListIndexesCommand) {
-    TaskExecutorWithFailureInScheduleRemoteCommand _executorProxy(
-        &getExecutor(), [](const executor::RemoteCommandRequest& request) {
-            return str::equals("listIndexes", request.cmdObj.firstElementFieldName());
-        });
-
-    collectionCloner = stdx::make_unique<CollectionCloner>(
-        &_executorProxy,
-        dbWorkThreadPool.get(),
-        target,
-        nss,
-        options,
-        stdx::bind(&CollectionClonerTest::setStatus, this, stdx::placeholders::_1),
-        storageInterface.get());
-
-    ASSERT_OK(collectionCloner->startup());
-
-    {
-        executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(100));
-    }
-    collectionCloner->join();
-    ASSERT_EQUALS(ErrorCodes::OperationFailed, getStatus());
-}
-
 TEST_F(CollectionClonerTest, DoNotCreateIDIndexIfAutoIndexIdUsed) {
     options.reset();
     options.autoIndexId = CollectionOptions::NO;
@@ -351,7 +216,6 @@ TEST_F(CollectionClonerTest, DoNotCreateIDIndexIfAutoIndexIdUsed) {
     ASSERT_OK(collectionCloner->startup());
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSONArray()));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -385,7 +249,6 @@ TEST_F(CollectionClonerTest, ListIndexesReturnedNoIndexes) {
     // the cloner stops the fetcher from retrieving more results.
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(1, BSONArray()));
     }
 
@@ -415,7 +278,6 @@ TEST_F(CollectionClonerTest, ListIndexesReturnedNamespaceNotFound) {
     // the cloner stops the fetcher from retrieving more results.
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(ErrorCodes::NamespaceNotFound, "The collection doesn't exist.");
     }
 
@@ -454,7 +316,6 @@ TEST_F(CollectionClonerTest,
     // the cloner stops the fetcher from retrieving more results.
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(ErrorCodes::NamespaceNotFound, "The collection doesn't exist.");
     }
 
@@ -476,7 +337,6 @@ TEST_F(CollectionClonerTest, BeginCollectionScheduleDbWorkFailed) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -502,7 +362,6 @@ TEST_F(CollectionClonerTest, BeginCollectionCallbackCanceled) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -523,7 +382,6 @@ TEST_F(CollectionClonerTest, BeginCollectionFailed) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -566,7 +424,6 @@ TEST_F(CollectionClonerTest, BeginCollection) {
     // First batch contains the _id_ index spec.
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(1, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -617,7 +474,6 @@ TEST_F(CollectionClonerTest, FindFetcherScheduleFailed) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -645,7 +501,6 @@ TEST_F(CollectionClonerTest, FindCommandAfterBeginCollection) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -670,7 +525,6 @@ TEST_F(CollectionClonerTest, FindCommandFailed) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -695,7 +549,6 @@ TEST_F(CollectionClonerTest, FindCommandCanceled) {
     ASSERT_TRUE(collectionCloner->isActive());
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         scheduleNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -733,7 +586,6 @@ TEST_F(CollectionClonerTest, InsertDocumentsScheduleDbWorkFailed) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -761,7 +613,6 @@ TEST_F(CollectionClonerTest, InsertDocumentsCallbackCanceled) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
 
@@ -795,7 +646,6 @@ TEST_F(CollectionClonerTest, InsertDocumentsFailed) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -829,7 +679,6 @@ TEST_F(CollectionClonerTest, InsertDocumentsSingleBatch) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -860,7 +709,6 @@ TEST_F(CollectionClonerTest, InsertDocumentsMultipleBatches) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -905,7 +753,6 @@ TEST_F(CollectionClonerTest, LastBatchContainsNoDocuments) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -958,7 +805,6 @@ TEST_F(CollectionClonerTest, MiddleBatchContainsNoDocuments) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -1020,7 +866,6 @@ TEST_F(CollectionClonerTest, CollectionClonerCanBeRestartedAfterPreviousFailure)
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
@@ -1063,7 +908,6 @@ TEST_F(CollectionClonerTest, CollectionClonerCanBeRestartedAfterPreviousFailure)
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(collectionCloner->isActive());
diff --git a/src/mongo/db/repl/data_replicator_test.cpp b/src/mongo/db/repl/data_replicator_test.cpp
index 4fe4426b60a..69994599db2 100644
--- a/src/mongo/db/repl/data_replicator_test.cpp
+++ b/src/mongo/db/repl/data_replicator_test.cpp
@@ -689,59 +689,54 @@ TEST_F(InitialSyncTest, Complete) {
      *
      */
 
-    auto lastOpAfterClone = BSON(
-        "ts" << Timestamp(Seconds(8), 1U) << "h" << 1LL << "v" << OplogEntry::kOplogVersion << "ns"
-             << ""
-             << "op"
-             << "i"
-             << "o"
-             << BSON("_id" << 5 << "a" << 2));
-
-    const Responses responses = {
-        {"replSetGetRBID", fromjson(str::stream() << "{ok: 1, rbid:1}")},
-        // get latest oplog ts
-        {"find",
-         fromjson(
-             str::stream() << "{ok:1, cursor:{id:NumberLong(0), ns:'local.oplog.rs', firstBatch:["
-                              "{ts:Timestamp(1,1), h:NumberLong(1), ns:'a.a', v:"
-                           << OplogEntry::kOplogVersion
-                           << ", op:'i', o:{_id:1, a:1}}]}}")},
-        // oplog fetcher find
-        {"find",
-         fromjson(
-             str::stream() << "{ok:1, cursor:{id:NumberLong(1), ns:'local.oplog.rs', firstBatch:["
-                              "{ts:Timestamp(1,1), h:NumberLong(1), ns:'a.a', v:"
-                           << OplogEntry::kOplogVersion
-                           << ", op:'i', o:{_id:1, a:1}}]}}")},
-        // Clone Start
-        // listDatabases
-        {"listDatabases", fromjson("{ok:1, databases:[{name:'a'}]}")},
-        // listCollections for "a"
-        {"listCollections",
-         fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
-                  "{name:'a', options:{}} "
-                  "]}}")},
-        // count:a
-        {"count", BSON("n" << 1 << "ok" << 1)},
-        // listIndexes:a
+    const Responses responses =
         {
-            "listIndexes",
-            fromjson(str::stream()
-                     << "{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listIndexes.a', firstBatch:["
-                        "{v:"
-                     << OplogEntry::kOplogVersion
-                     << ", key:{_id:1}, name:'_id_', ns:'a.a'}]}}")},
-        // find:a
-        {"find",
-         fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.a', firstBatch:["
-                  "{_id:1, a:1} "
-                  "]}}")},
-        // Clone Done
-        // get latest oplog ts
-        {"find", BaseClonerTest::createCursorResponse(0, BSON_ARRAY(lastOpAfterClone))},
-        {"replSetGetRBID", fromjson(str::stream() << "{ok: 1, rbid:1}")},
-        // Applier starts ...
-    };
+            {"replSetGetRBID", fromjson(str::stream() << "{ok: 1, rbid:1}")},
+            // get latest oplog ts
+            {"find",
+             fromjson(str::stream()
+                      << "{ok:1, cursor:{id:NumberLong(0), ns:'local.oplog.rs', firstBatch:["
+                         "{ts:Timestamp(1,1), h:NumberLong(1), ns:'a.a', v:"
+                      << OplogEntry::kOplogVersion
+                      << ", op:'i', o:{_id:1, a:1}}]}}")},
+            // oplog fetcher find
+            {"find",
+             fromjson(str::stream()
+                      << "{ok:1, cursor:{id:NumberLong(1), ns:'local.oplog.rs', firstBatch:["
+                         "{ts:Timestamp(1,1), h:NumberLong(1), ns:'a.a', v:"
+                      << OplogEntry::kOplogVersion
+                      << ", op:'i', o:{_id:1, a:1}}]}}")},
+            // Clone Start
+            // listDatabases
+            {"listDatabases", fromjson("{ok:1, databases:[{name:'a'}]}")},
+            // listCollections for "a"
+            {"listCollections",
+             fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
+                      "{name:'a', options:{}} "
+                      "]}}")},
+            // listIndexes:a
+            {"listIndexes",
+             fromjson(str::stream()
+                      << "{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listIndexes.a', firstBatch:["
+                         "{v:"
+                      << OplogEntry::kOplogVersion
+                      << ", key:{_id:1}, name:'_id_', ns:'a.a'}]}}")},
+            // find:a
+            {"find",
+             fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.a', firstBatch:["
+                      "{_id:1, a:1} "
+                      "]}}")},
+            // Clone Done
+            // get latest oplog ts
+            {"find",
+             fromjson(str::stream()
+                      << "{ok:1, cursor:{id:NumberLong(0), ns:'local.oplog.rs', firstBatch:["
+                         "{ts:Timestamp(7,1), h:NumberLong(1), ns:'a.a', v:"
+                      << OplogEntry::kOplogVersion
+                      << ", op:'i', o:{_id:5, a:2}}]}}")},
+            {"replSetGetRBID", fromjson(str::stream() << "{ok: 1, rbid:1}")},
+            // Applier starts ...
+        };
 
     // Initial sync flag should not be set before starting.
     auto txn = makeOpCtx();
@@ -751,7 +746,7 @@ TEST_F(InitialSyncTest, Complete) {
 
     // Play first response to ensure data replicator has entered initial sync state.
     setResponses({responses.begin(), responses.begin() + 1});
-    numGetMoreOplogEntriesMax = responses.size();
+    numGetMoreOplogEntriesMax = 6;
     playResponses();
 
     // Initial sync flag should be set.
@@ -778,7 +773,9 @@ TEST_F(InitialSyncTest, Complete) {
     ASSERT_FALSE(getStorage().getInitialSyncFlag(txn.get()));
 
     // getMore responses are generated by playResponses().
-    ASSERT_EQUALS(OplogEntry(lastOpAfterClone).getOpTime(), _myLastOpTime);
+    ASSERT_EQUALS(OpTime(Timestamp(7, 1), OpTime::kUninitializedTerm),
+                  OplogEntry(lastGetMoreOplogEntry).getOpTime());
+    ASSERT_EQUALS(OplogEntry(lastGetMoreOplogEntry).getOpTime(), _myLastOpTime);
 }
 
 TEST_F(InitialSyncTest, LastOpTimeShouldBeSetEvenIfNoOperationsAreAppliedAfterCloning) {
@@ -807,8 +804,6 @@ TEST_F(InitialSyncTest, LastOpTimeShouldBeSetEvenIfNoOperationsAreAppliedAfterCl
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 1 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -944,8 +939,6 @@ TEST_F(InitialSyncTest, FailOnRollback) {
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 1 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -972,7 +965,7 @@ TEST_F(InitialSyncTest, FailOnRollback) {
         };
 
     startSync(1);
-    numGetMoreOplogEntriesMax = responses.size();
+    numGetMoreOplogEntriesMax = 5;
     setResponses(responses);
     playResponses();
     verifySync(getNet(), ErrorCodes::UnrecoverableRollbackError);
@@ -1005,8 +998,6 @@ TEST_F(InitialSyncTest, DataReplicatorPassesThroughRollbackCheckerScheduleError)
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 1 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -1032,7 +1023,7 @@ TEST_F(InitialSyncTest, DataReplicatorPassesThroughRollbackCheckerScheduleError)
         };
 
     startSync(1);
-    numGetMoreOplogEntriesMax = responses.size();
+    numGetMoreOplogEntriesMax = 5;
     setResponses(responses);
     playResponses();
     getExecutor().shutdown();
@@ -1110,8 +1101,6 @@ TEST_F(InitialSyncTest, OplogOutOfOrderOnOplogFetchFinish) {
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 1 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -1153,7 +1142,7 @@ TEST_F(InitialSyncTest, OplogOutOfOrderOnOplogFetchFinish) {
 
     startSync(1);
 
-    numGetMoreOplogEntriesMax = responses.size();
+    numGetMoreOplogEntriesMax = 10;
     setResponses({responses.begin(), responses.end() - 4});
     playResponses();
     log() << "done playing first responses";
@@ -1193,8 +1182,6 @@ TEST_F(InitialSyncTest, InitialSyncStateIsResetAfterFailure) {
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 1 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -1221,7 +1208,7 @@ TEST_F(InitialSyncTest, InitialSyncStateIsResetAfterFailure) {
 
     startSync(2);
 
-    numGetMoreOplogEntriesMax = responses.size();
+    numGetMoreOplogEntriesMax = 6;
     setResponses(responses);
     playResponses();
     log() << "done playing first responses";
@@ -1290,8 +1277,6 @@ TEST_F(InitialSyncTest, GetInitialSyncProgressReturnsCorrectProgress) {
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 5 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -1342,7 +1327,7 @@ TEST_F(InitialSyncTest, GetInitialSyncProgressReturnsCorrectProgress) {
 
     // Play first 2 responses to ensure data replicator has started the oplog fetcher.
     setResponses({failedResponses.begin(), failedResponses.begin() + 2});
-    numGetMoreOplogEntriesMax = failedResponses.size() + successfulResponses.size();
+    numGetMoreOplogEntriesMax = 10;
     playResponses();
     log() << "Done playing first failed response";
 
@@ -1412,12 +1397,7 @@ TEST_F(InitialSyncTest, GetInitialSyncProgressReturnsCorrectProgress) {
     ASSERT_EQUALS(1, dbProgress.getIntField("collections")) << dbProgress;
     ASSERT_EQUALS(1, dbProgress.getIntField("clonedCollections")) << dbProgress;
     auto collectionProgress = dbProgress.getObjectField("a.a");
-    ASSERT_EQUALS(
-        5, collectionProgress.getIntField(CollectionCloner::Stats::kDocumentsToCopyFieldName))
-        << collectionProgress;
-    ASSERT_EQUALS(
-        5, collectionProgress.getIntField(CollectionCloner::Stats::kDocumentsCopiedFieldName))
-        << collectionProgress;
+    ASSERT_EQUALS(5, collectionProgress.getIntField("documents")) << collectionProgress;
     ASSERT_EQUALS(1, collectionProgress.getIntField("indexes")) << collectionProgress;
     ASSERT_EQUALS(5, collectionProgress.getIntField("fetchedBatches")) << collectionProgress;
 
diff --git a/src/mongo/db/repl/database_cloner_test.cpp b/src/mongo/db/repl/database_cloner_test.cpp
index e5cb2b464e2..94e93be5be4 100644
--- a/src/mongo/db/repl/database_cloner_test.cpp
+++ b/src/mongo/db/repl/database_cloner_test.cpp
@@ -540,7 +540,6 @@ TEST_F(DatabaseClonerTest, StartSecondCollectionClonerFailed) {
                                                                                 << "options"
                                                                                 << BSONObj()))));
 
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
         processNetworkResponse(createCursorResponse(0, BSONArray()));
     }
@@ -572,13 +571,11 @@ TEST_F(DatabaseClonerTest, FirstCollectionListIndexesFailed) {
     // This affects the order of the network responses.
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(BSON("ok" << 0 << "errmsg"
                                          << "fake message"
                                          << "code"
                                          << ErrorCodes::CursorNotFound));
 
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
         processNetworkResponse(createCursorResponse(0, BSONArray()));
     }
@@ -624,7 +621,6 @@ TEST_F(DatabaseClonerTest, CreateCollections) {
     // This affects the order of the network responses.
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(_databaseCloner->isActive());
@@ -636,7 +632,6 @@ TEST_F(DatabaseClonerTest, CreateCollections) {
 
     {
         executor::NetworkInterfaceMock::InNetworkGuard guard(getNet());
-        processNetworkResponse(createCountResponse(0));
         processNetworkResponse(createListIndexesResponse(0, BSON_ARRAY(idIndexSpec)));
     }
     ASSERT_TRUE(_databaseCloner->isActive());
diff --git a/src/mongo/db/repl/databases_cloner_test.cpp b/src/mongo/db/repl/databases_cloner_test.cpp
index 740a194e490..110db06f9d8 100644
--- a/src/mongo/db/repl/databases_cloner_test.cpp
+++ b/src/mongo/db/repl/databases_cloner_test.cpp
@@ -628,8 +628,6 @@ TEST_F(DBsClonerTest, SingleDatabaseCopiesCompletely) {
          fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                   "{name:'a', options:{}} "
                   "]}}")},
-        // count:a
-        {"count", BSON("n" << 1 << "ok" << 1)},
         // listIndexes:a
         {
             "listIndexes",
@@ -659,8 +657,6 @@ TEST_F(DBsClonerTest, TwoDatabasesCopiesCompletely) {
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'a.$cmd.listCollections', firstBatch:["
                       "{name:'a', options:{}} "
                       "]}}")},
-            // count:a
-            {"count", BSON("n" << 1 << "ok" << 1)},
             // listIndexes:a
             {"listIndexes",
              fromjson(str::stream()
@@ -678,8 +674,6 @@ TEST_F(DBsClonerTest, TwoDatabasesCopiesCompletely) {
              fromjson("{ok:1, cursor:{id:NumberLong(0), ns:'b.$cmd.listCollections', firstBatch:["
                       "{name:'b', options:{}} "
                       "]}}")},
-            // count:b
-            {"count", BSON("n" << 2 << "ok" << 1)},
             // listIndexes:b
             {"listIndexes",
              fromjson(str::stream()