SERVER-76268 Create FallbackOpObserver

5 files changed, 307 insertions, 116 deletions

diff --git a/src/mongo/db/op_observer/SConscript b/src/mongo/db/op_observer/SConscript
index c941ccc1610..95502c35710 100644
--- a/src/mongo/db/op_observer/SConscript
+++ b/src/mongo/db/op_observer/SConscript
@@ -18,12 +18,14 @@ env.Library(
     target='op_observer_util',
     source=[
         'op_observer_util.cpp',
+        'batched_write_context.cpp',
     ],
     LIBDEPS_PRIVATE=[
         '$BUILD_DIR/mongo/base',
         '$BUILD_DIR/mongo/db/bson/dotted_path_support',
         '$BUILD_DIR/mongo/db/catalog/collection_options',
         '$BUILD_DIR/mongo/db/shard_role_api',
+        '$BUILD_DIR/mongo/db/transaction/transaction_operations',
     ],
 )
 
@@ -52,7 +54,6 @@ env.Library(
     target='op_observer_impl',
     source=[
         'op_observer_impl.cpp',
-        'batched_write_context.cpp',
     ],
     LIBDEPS=[
         'op_observer',
@@ -77,11 +78,9 @@ env.Library(
         '$BUILD_DIR/mongo/db/repl/repl_server_parameters',
         '$BUILD_DIR/mongo/db/repl/tenant_migration_access_blocker',
         '$BUILD_DIR/mongo/db/server_feature_flags',
-        '$BUILD_DIR/mongo/db/session/session_catalog',
         '$BUILD_DIR/mongo/db/session/session_catalog_mongod',
         '$BUILD_DIR/mongo/db/transaction/transaction',
         '$BUILD_DIR/mongo/db/transaction/transaction_operations',
-        '$BUILD_DIR/mongo/db/views/view_catalog_helpers',
         '$BUILD_DIR/mongo/s/coreshard',
         '$BUILD_DIR/mongo/s/grid',
         'op_observer_util',
@@ -161,3 +160,22 @@ env.CppUnitTest(
         'user_write_block_mode_op_observer',
     ],
 )
+
+env.Library(
+    target='fallback_op_observer',
+    source=[
+        'fallback_op_observer.cpp',
+    ],
+    LIBDEPS=[
+        'op_observer',
+    ],
+    LIBDEPS_PRIVATE=[
+        '$BUILD_DIR/mongo/db/catalog/collection_catalog',
+        '$BUILD_DIR/mongo/db/read_write_concern_defaults',
+        '$BUILD_DIR/mongo/db/session/session_catalog',
+        '$BUILD_DIR/mongo/db/session/session_catalog_mongod',
+        '$BUILD_DIR/mongo/db/transaction/transaction',
+        '$BUILD_DIR/mongo/db/views/view_catalog_helpers',
+        'op_observer_util',
+    ],
+)
diff --git a/src/mongo/db/op_observer/batched_write_context.h b/src/mongo/db/op_observer/batched_write_context.h
index d1972e69880..def884044e6 100644
--- a/src/mongo/db/op_observer/batched_write_context.h
+++ b/src/mongo/db/op_observer/batched_write_context.h
@@ -30,7 +30,6 @@
 #pragma once
 
 #include "mongo/db/operation_context.h"
-#include "mongo/db/repl/oplog_entry.h"
 #include "mongo/db/transaction/transaction_operations.h"
 
 namespace mongo {
diff --git a/src/mongo/db/op_observer/fallback_op_observer.cpp b/src/mongo/db/op_observer/fallback_op_observer.cpp
new file mode 100644
index 00000000000..d163e89ce8c
--- /dev/null
+++ b/src/mongo/db/op_observer/fallback_op_observer.cpp
@@ -0,0 +1,209 @@
+/**
+ *    Copyright (C) 2023-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/db/op_observer/fallback_op_observer.h"
+
+#include "mongo/db/catalog/collection_catalog.h"
+#include "mongo/db/keys_collection_document_gen.h"
+#include "mongo/db/logical_time_validator.h"
+#include "mongo/db/op_observer/batched_write_context.h"
+#include "mongo/db/op_observer/op_observer_util.h"
+#include "mongo/db/read_write_concern_defaults.h"
+#include "mongo/db/session/session_catalog.h"
+#include "mongo/db/session/session_catalog_mongod.h"
+#include "mongo/db/session/session_killer.h"
+#include "mongo/db/views/util.h"
+#include "mongo/db/views/view_catalog_helpers.h"
+#include "mongo/util/namespace_string_util.h"
+
+namespace mongo {
+
+void FallbackOpObserver::onInserts(OperationContext* opCtx,
+                                   const CollectionPtr& coll,
+                                   std::vector<InsertStatement>::const_iterator first,
+                                   std::vector<InsertStatement>::const_iterator last,
+                                   std::vector<bool> fromMigrate,
+                                   bool defaultFromMigrate,
+                                   InsertsOpStateAccumulator* opAccumulator) {
+    auto txnParticipant = TransactionParticipant::get(opCtx);
+    const bool inMultiDocumentTransaction =
+        txnParticipant && opCtx->writesAreReplicated() && txnParticipant.transactionIsOpen();
+    if (inMultiDocumentTransaction && !opCtx->getWriteUnitOfWork()) {
+        return;
+    }
+
+    const auto& nss = coll->ns();
+
+    if (nss.isSystemDotJavascript()) {
+        Scope::storedFuncMod(opCtx);
+    } else if (nss.isSystemDotViews()) {
+        try {
+            for (auto it = first; it != last; it++) {
+                view_util::validateViewDefinitionBSON(opCtx, it->doc, nss.dbName());
+
+                uassertStatusOK(CollectionCatalog::get(opCtx)->createView(
+                    opCtx,
+                    NamespaceStringUtil::deserialize(nss.dbName().tenantId(),
+                                                     it->doc.getStringField("_id")),
+                    NamespaceStringUtil::parseNamespaceFromDoc(nss.dbName(),
+                                                               it->doc.getStringField("viewOn")),
+                    BSONArray{it->doc.getObjectField("pipeline")},
+                    view_catalog_helpers::validatePipeline,
+                    it->doc.getObjectField("collation"),
+                    ViewsForDatabase::Durability::kAlreadyDurable));
+            }
+        } catch (const DBException&) {
+            // If a previous operation left the view catalog in an invalid state, our inserts can
+            // fail even if all the definitions are valid. Reloading may help us reset the state.
+            CollectionCatalog::get(opCtx)->reloadViews(opCtx, nss.dbName());
+        }
+    } else if (nss == NamespaceString::kSessionTransactionsTableNamespace) {
+        if (opAccumulator) {
+            auto& opTimeList = opAccumulator->opTimes;
+            if (!opTimeList.empty() && !opTimeList.back().isNull()) {
+                for (auto it = first; it != last; it++) {
+                    auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
+                    mongoDSessionCatalog->observeDirectWriteToConfigTransactions(opCtx, it->doc);
+                }
+            }
+        }
+    } else if (nss == NamespaceString::kConfigSettingsNamespace) {
+        for (auto it = first; it != last; it++) {
+            ReadWriteConcernDefaults::get(opCtx).observeDirectWriteToConfigSettings(
+                opCtx, it->doc["_id"], it->doc);
+        }
+    } else if (nss == NamespaceString::kExternalKeysCollectionNamespace) {
+        for (auto it = first; it != last; it++) {
+            auto externalKey =
+                ExternalKeysCollectionDocument::parse(IDLParserContext("externalKey"), it->doc);
+            opCtx->recoveryUnit()->onCommit(
+                [this, externalKey = std::move(externalKey)](OperationContext* opCtx,
+                                                             boost::optional<Timestamp>) mutable {
+                    auto validator = LogicalTimeValidator::get(opCtx);
+                    if (validator) {
+                        validator->cacheExternalKey(externalKey);
+                    }
+                });
+        }
+    }
+}
+
+void FallbackOpObserver::onUpdate(OperationContext* opCtx,
+                                  const OplogUpdateEntryArgs& args,
+                                  OpStateAccumulator* opAccumulator) {
+    if (args.updateArgs->update.isEmpty()) {
+        return;
+    }
+
+    const auto& nss = args.coll->ns();
+
+    if (nss.isSystemDotJavascript()) {
+        Scope::storedFuncMod(opCtx);
+    } else if (nss.isSystemDotViews()) {
+        CollectionCatalog::get(opCtx)->reloadViews(opCtx, nss.dbName());
+    } else if (nss == NamespaceString::kSessionTransactionsTableNamespace &&
+               !opAccumulator->opTime.writeOpTime.isNull()) {
+        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
+        mongoDSessionCatalog->observeDirectWriteToConfigTransactions(opCtx,
+                                                                     args.updateArgs->updatedDoc);
+    } else if (nss == NamespaceString::kConfigSettingsNamespace) {
+        ReadWriteConcernDefaults::get(opCtx).observeDirectWriteToConfigSettings(
+            opCtx, args.updateArgs->updatedDoc["_id"], args.updateArgs->updatedDoc);
+    }
+}
+
+void FallbackOpObserver::onDelete(OperationContext* opCtx,
+                                  const CollectionPtr& coll,
+                                  StmtId stmtId,
+                                  const OplogDeleteEntryArgs& args,
+                                  OpStateAccumulator* opAccumulator) {
+    const auto& nss = coll->ns();
+    const bool inBatchedWrite = BatchedWriteContext::get(opCtx).writesAreBatched();
+
+    auto optDocKey = repl::documentKeyDecoration(opCtx);
+    invariant(optDocKey, nss.toStringForErrorMsg());
+    auto& documentKey = optDocKey.value();
+
+    if (nss.isSystemDotJavascript()) {
+        Scope::storedFuncMod(opCtx);
+    } else if (nss.isSystemDotViews()) {
+        CollectionCatalog::get(opCtx)->reloadViews(opCtx, nss.dbName());
+    } else if (nss == NamespaceString::kSessionTransactionsTableNamespace &&
+               (inBatchedWrite || !opAccumulator->opTime.writeOpTime.isNull())) {
+        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
+        mongoDSessionCatalog->observeDirectWriteToConfigTransactions(opCtx, documentKey.getId());
+    } else if (nss == NamespaceString::kConfigSettingsNamespace) {
+        ReadWriteConcernDefaults::get(opCtx).observeDirectWriteToConfigSettings(
+            opCtx, documentKey.getId().firstElement(), boost::none);
+    }
+}
+
+void FallbackOpObserver::onDropDatabase(OperationContext* opCtx, const DatabaseName& dbName) {
+    if (dbName.db() == NamespaceString::kSessionTransactionsTableNamespace.db()) {
+        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
+        mongoDSessionCatalog->invalidateAllSessions(opCtx);
+    }
+}
+
+repl::OpTime FallbackOpObserver::onDropCollection(OperationContext* opCtx,
+                                                  const NamespaceString& collectionName,
+                                                  const UUID& uuid,
+                                                  std::uint64_t numRecords,
+                                                  CollectionDropType dropType) {
+    if (collectionName.isSystemDotJavascript()) {
+        Scope::storedFuncMod(opCtx);
+    } else if (collectionName.isSystemDotViews()) {
+        CollectionCatalog::get(opCtx)->clearViews(opCtx, collectionName.dbName());
+    } else if (collectionName == NamespaceString::kSessionTransactionsTableNamespace) {
+        // Disallow this drop if there are currently prepared transactions.
+        const auto sessionCatalog = SessionCatalog::get(opCtx);
+        SessionKiller::Matcher matcherAllSessions(
+            KillAllSessionsByPatternSet{makeKillAllSessionsByPattern(opCtx)});
+        bool noPreparedTxns = true;
+        sessionCatalog->scanSessions(matcherAllSessions, [&](const ObservableSession& session) {
+            auto txnParticipant = TransactionParticipant::get(session);
+            if (txnParticipant.transactionIsPrepared()) {
+                noPreparedTxns = false;
+            }
+        });
+        uassert(4852500,
+                "Unable to drop transactions table (config.transactions) while prepared "
+                "transactions are present.",
+                noPreparedTxns);
+
+        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
+        mongoDSessionCatalog->invalidateAllSessions(opCtx);
+    } else if (collectionName == NamespaceString::kConfigSettingsNamespace) {
+        ReadWriteConcernDefaults::get(opCtx).invalidate();
+    }
+
+    return {};
+}
+
+}  // namespace mongo
diff --git a/src/mongo/db/op_observer/fallback_op_observer.h b/src/mongo/db/op_observer/fallback_op_observer.h
new file mode 100644
index 00000000000..5c5d86f04da
--- /dev/null
+++ b/src/mongo/db/op_observer/fallback_op_observer.h
@@ -0,0 +1,76 @@
+/**
+ *    Copyright (C) 2023-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/op_observer/op_observer_noop.h"
+
+namespace mongo {
+
+/**
+ * This OpObserver contains notifications to miscellaneous entities that were sitting in
+ * OpObserverImpl.
+ */
+class FallbackOpObserver final : public OpObserverNoop {
+    FallbackOpObserver(const FallbackOpObserver&) = delete;
+    FallbackOpObserver& operator=(const FallbackOpObserver&) = delete;
+
+public:
+    FallbackOpObserver() = default;
+    ~FallbackOpObserver() = default;
+
+    void onInserts(OperationContext* opCtx,
+                   const CollectionPtr& coll,
+                   std::vector<InsertStatement>::const_iterator first,
+                   std::vector<InsertStatement>::const_iterator last,
+                   std::vector<bool> fromMigrate,
+                   bool defaultFromMigrate,
+                   InsertsOpStateAccumulator* opAccumulator = nullptr) final;
+
+    void onUpdate(OperationContext* opCtx,
+                  const OplogUpdateEntryArgs& args,
+                  OpStateAccumulator* opAccumulator = nullptr) final;
+
+    void onDelete(OperationContext* opCtx,
+                  const CollectionPtr& coll,
+                  StmtId stmtId,
+                  const OplogDeleteEntryArgs& args,
+                  OpStateAccumulator* opAccumulator = nullptr) final;
+
+    void onDropDatabase(OperationContext* opCtx, const DatabaseName& dbName) final;
+
+    using OpObserver::onDropCollection;
+    repl::OpTime onDropCollection(OperationContext* opCtx,
+                                  const NamespaceString& collectionName,
+                                  const UUID& uuid,
+                                  std::uint64_t numRecords,
+                                  CollectionDropType dropType) final;
+};
+
+}  // namespace mongo
diff --git a/src/mongo/db/op_observer/op_observer_impl.cpp b/src/mongo/db/op_observer/op_observer_impl.cpp
index 15aa42df6f6..0b2d446358f 100644
--- a/src/mongo/db/op_observer/op_observer_impl.cpp
+++ b/src/mongo/db/op_observer/op_observer_impl.cpp
@@ -50,7 +50,6 @@
 #include "mongo/db/create_indexes_gen.h"
 #include "mongo/db/dbhelpers.h"
 #include "mongo/db/index/index_descriptor.h"
-#include "mongo/db/keys_collection_document_gen.h"
 #include "mongo/db/logical_time_validator.h"
 #include "mongo/db/multitenancy_gen.h"
 #include "mongo/db/namespace_string.h"
@@ -69,12 +68,10 @@
 #include "mongo/db/s/sharding_write_router.h"
 #include "mongo/db/server_feature_flags_gen.h"
 #include "mongo/db/server_options.h"
-#include "mongo/db/session/session_catalog_mongod.h"
+#include "mongo/db/session/session_txn_record_gen.h"
 #include "mongo/db/storage/storage_parameters_gen.h"
 #include "mongo/db/transaction/transaction_participant.h"
 #include "mongo/db/transaction/transaction_participant_gen.h"
-#include "mongo/db/views/util.h"
-#include "mongo/db/views/view_catalog_helpers.h"
 #include "mongo/logv2/log.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/grid.h"
@@ -831,54 +828,6 @@ void OpObserverImpl::onInserts(OperationContext* opCtx,
                           shardingWriteRouter,
                           defaultFromMigrate,
                           inMultiDocumentTransaction);
-
-    if (nss.coll() == "system.js") {
-        Scope::storedFuncMod(opCtx);
-    } else if (nss.isSystemDotViews()) {
-        try {
-            for (auto it = first; it != last; it++) {
-                view_util::validateViewDefinitionBSON(opCtx, it->doc, nss.dbName());
-
-                uassertStatusOK(CollectionCatalog::get(opCtx)->createView(
-                    opCtx,
-                    NamespaceStringUtil::deserialize(nss.dbName().tenantId(),
-                                                     it->doc.getStringField("_id")),
-                    NamespaceStringUtil::parseNamespaceFromDoc(nss.dbName(),
-                                                               it->doc.getStringField("viewOn")),
-                    BSONArray{it->doc.getObjectField("pipeline")},
-                    view_catalog_helpers::validatePipeline,
-                    it->doc.getObjectField("collation"),
-                    ViewsForDatabase::Durability::kAlreadyDurable));
-            }
-        } catch (const DBException&) {
-            // If a previous operation left the view catalog in an invalid state, our inserts can
-            // fail even if all the definitions are valid. Reloading may help us reset the state.
-            CollectionCatalog::get(opCtx)->reloadViews(opCtx, nss.dbName());
-        }
-    } else if (nss == NamespaceString::kSessionTransactionsTableNamespace && !lastOpTime.isNull()) {
-        for (auto it = first; it != last; it++) {
-            auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
-            mongoDSessionCatalog->observeDirectWriteToConfigTransactions(opCtx, it->doc);
-        }
-    } else if (nss == NamespaceString::kConfigSettingsNamespace) {
-        for (auto it = first; it != last; it++) {
-            ReadWriteConcernDefaults::get(opCtx).observeDirectWriteToConfigSettings(
-                opCtx, it->doc["_id"], it->doc);
-        }
-    } else if (nss == NamespaceString::kExternalKeysCollectionNamespace) {
-        for (auto it = first; it != last; it++) {
-            auto externalKey =
-                ExternalKeysCollectionDocument::parse(IDLParserContext("externalKey"), it->doc);
-            opCtx->recoveryUnit()->onCommit(
-                [this, externalKey = std::move(externalKey)](OperationContext* opCtx,
-                                                             boost::optional<Timestamp>) mutable {
-                    auto validator = LogicalTimeValidator::get(opCtx);
-                    if (validator) {
-                        validator->cacheExternalKey(externalKey);
-                    }
-                });
-        }
-    }
 }
 
 void OpObserverImpl::onInsertGlobalIndexKey(OperationContext* opCtx,
@@ -1103,20 +1052,6 @@ void OpObserverImpl::onUpdate(OperationContext* opCtx,
                                  inMultiDocumentTransaction);
         }
     }
-
-    if (args.coll->ns().coll() == "system.js") {
-        Scope::storedFuncMod(opCtx);
-    } else if (args.coll->ns().isSystemDotViews()) {
-        CollectionCatalog::get(opCtx)->reloadViews(opCtx, args.coll->ns().dbName());
-    } else if (args.coll->ns() == NamespaceString::kSessionTransactionsTableNamespace &&
-               !opTime.writeOpTime.isNull()) {
-        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
-        mongoDSessionCatalog->observeDirectWriteToConfigTransactions(opCtx,
-                                                                     args.updateArgs->updatedDoc);
-    } else if (args.coll->ns() == NamespaceString::kConfigSettingsNamespace) {
-        ReadWriteConcernDefaults::get(opCtx).observeDirectWriteToConfigSettings(
-            opCtx, args.updateArgs->updatedDoc["_id"], args.updateArgs->updatedDoc);
-    }
 }
 
 void OpObserverImpl::aboutToDelete(OperationContext* opCtx,
@@ -1263,19 +1198,6 @@ void OpObserverImpl::onDelete(OperationContext* opCtx,
                                  inMultiDocumentTransaction);
         }
     }
-
-    if (nss.coll() == "system.js") {
-        Scope::storedFuncMod(opCtx);
-    } else if (nss.isSystemDotViews()) {
-        CollectionCatalog::get(opCtx)->reloadViews(opCtx, nss.dbName());
-    } else if (nss == NamespaceString::kSessionTransactionsTableNamespace &&
-               (inBatchedWrite || !opTime.writeOpTime.isNull())) {
-        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
-        mongoDSessionCatalog->observeDirectWriteToConfigTransactions(opCtx, documentKey.getId());
-    } else if (nss == NamespaceString::kConfigSettingsNamespace) {
-        ReadWriteConcernDefaults::get(opCtx).observeDirectWriteToConfigSettings(
-            opCtx, documentKey.getId().firstElement(), boost::none);
-    }
 }
 
 void OpObserverImpl::onInternalOpMessage(
@@ -1432,11 +1354,6 @@ void OpObserverImpl::onDropDatabase(OperationContext* opCtx, const DatabaseName&
     uassert(50714,
             "dropping the admin database is not allowed.",
             dbName.db() != DatabaseName::kAdmin.db());
-
-    if (dbName.db() == NamespaceString::kSessionTransactionsTableNamespace.db()) {
-        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
-        mongoDSessionCatalog->invalidateAllSessions(opCtx);
-    }
 }
 
 repl::OpTime OpObserverImpl::onDropCollection(OperationContext* opCtx,
@@ -1479,34 +1396,6 @@ repl::OpTime OpObserverImpl::onDropCollection(OperationContext* opCtx,
             "dropping the server configuration collection (admin.system.version) is not allowed.",
             collectionName != NamespaceString::kServerConfigurationNamespace);
 
-    if (collectionName.isSystemDotViews()) {
-        CollectionCatalog::get(opCtx)->clearViews(opCtx, collectionName.dbName());
-    } else if (collectionName == NamespaceString::kSessionTransactionsTableNamespace) {
-        // Disallow this drop if there are currently prepared transactions.
-        const auto sessionCatalog = SessionCatalog::get(opCtx);
-        SessionKiller::Matcher matcherAllSessions(
-            KillAllSessionsByPatternSet{makeKillAllSessionsByPattern(opCtx)});
-        bool noPreparedTxns = true;
-        sessionCatalog->scanSessions(matcherAllSessions, [&](const ObservableSession& session) {
-            auto txnParticipant = TransactionParticipant::get(session);
-            if (txnParticipant.transactionIsPrepared()) {
-                noPreparedTxns = false;
-            }
-        });
-        uassert(4852500,
-                "Unable to drop transactions table (config.transactions) while prepared "
-                "transactions are present.",
-                noPreparedTxns);
-
-        auto mongoDSessionCatalog = MongoDSessionCatalog::get(opCtx);
-        mongoDSessionCatalog->invalidateAllSessions(opCtx);
-    } else if (collectionName == NamespaceString::kConfigSettingsNamespace) {
-        ReadWriteConcernDefaults::get(opCtx).invalidate();
-    } else if (collectionName.isSystemDotJavascript()) {
-        // Inform the JavaScript engine of the change to system.js.
-        Scope::storedFuncMod(opCtx);
-    }
-
     return {};
 }