SERVER-71818: Use the new cluster param

buildscripts/resmokeconfig/fully_disabled_feature_flags.yml

@@ -15,3 +15,5 @@
 # Disable the new logic for the resilient movePrimary for non-dedicated tests until the logic is
 # mature enough to be enabled for all tests.
 - featureFlagResilientMovePrimary
+# Disable the feature flag for catalog shard until most of the codebase can run in this mode.
+- featureFlagCatalogShard

jstests/noPassthrough/catalog_shard.js

@@ -0,0 +1,14 @@
+/**
+ * Tests catalog shard topology.
+ */
+(function() {
+"use strict";
+
+const st = new ShardingTest({
+    shards: 0,
+    config: 1,
+    configOptions: {setParameter: {featureFlagCatalogShard: true}},
+});
+
+st.stop();
+}());

src/mongo/db/SConscript

@@ -58,30 +58,22 @@ env.SConscript(
 # all the server binaries. It must not depend on anything other than utilities that are outside of
 # the server codebase.
 env.Library(
-    target='server_base', source=[
-        'basic_types.idl',
+    target='server_base',
+    source=[
         'database_name.cpp',
-        'feature_compatibility_version_parser.cpp',
-        'feature_compatibility_version_document.idl',
-        'feature_flag.cpp',
         'index_names.cpp',
         'keypattern.cpp',
-        'logical_time.cpp',
-        'multitenancy.idl',
-        'namespace_string.cpp',
-        'server_parameter_with_storage.cpp',
-        'server_parameter.cpp',
-        'server_parameter.idl',
         'shard_id.cpp',
         'shutdown_in_progress_quiesce_info.cpp',
         'tenant_id.cpp',
-    ], LIBDEPS=[
+    ],
+    LIBDEPS=[
         '$BUILD_DIR/mongo/base',
         '$BUILD_DIR/mongo/idl/idl_parser',
         '$BUILD_DIR/mongo/util/options_parser/options_parser',
-    ], LIBDEPS_PRIVATE=[
         'server_options_core',
-    ])
+    ],
+)
 
 #
 # The db/'common' lib has the abstractions that are shared by components of the
@@ -314,11 +306,24 @@ env.Library(
 env.Library(
     target="server_options_core",
     source=[
+        'basic_types.idl',
         "server_options.cpp",
+        "catalog_shard_feature_flag.idl",
+        "cluster_role.cpp",
+        'feature_compatibility_version_parser.cpp',
+        'feature_compatibility_version_document.idl',
+        "feature_flag.cpp",
+        'logical_time.cpp',
+        'multitenancy.idl',
+        'namespace_string.cpp',
+        'server_parameter_with_storage.cpp',
+        'server_parameter.cpp',
+        'server_parameter.idl',
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
         '$BUILD_DIR/mongo/bson/bson_validate',
+        '$BUILD_DIR/mongo/idl/idl_parser',
     ],
 )
 

src/mongo/db/catalog_shard_feature_flag.idl

@@ -0,0 +1,36 @@
+# Copyright (C) 2022-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.
+#
+
+global:
+    cpp_namespace: "mongo"
+
+feature_flags:
+    featureFlagCatalogShard:
+        description: "Feature flag for enabling shared config server/shard server cluster role"
+        cpp_varname: gFeatureFlagCatalogShard
+        default: false

src/mongo/db/cluster_role.cpp

@@ -0,0 +1,44 @@
+/**
+ *    Copyright (C) 2022-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/cluster_role.h"
+#include "mongo/db/catalog_shard_feature_flag_gen.h"
+#include "mongo/db/feature_flag.h"
+
+namespace mongo {
+
+bool ClusterRole::operator==(const ClusterRole& other) const {
+    if (gFeatureFlagCatalogShard.isEnabledAndIgnoreFCV() && _value == ClusterRole::ConfigServer) {
+        return other._value == ClusterRole::ConfigServer ||
+            other._value == ClusterRole::ShardServer;
+    }
+
+    return _value == other._value;
+}
+}  // namespace mongo

src/mongo/db/cluster_role.h

@@ -0,0 +1,63 @@
+/**
+ *    Copyright (C) 2022-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
+
+namespace mongo {
+/**
+ * ClusterRole is not mutually exclusive when featureFlagCatalogShard is true. In this mode, a
+ * config server cluster role is also a shard server cluster role.
+ */
+class ClusterRole {
+public:
+    enum Value {
+        None,
+        ShardServer,
+        ConfigServer,
+    };
+
+    ClusterRole(Value v = ClusterRole::None) : _value(v) {}
+
+    ClusterRole& operator=(const ClusterRole& rhs) {
+        if (this != &rhs) {
+            _value = rhs._value;
+        }
+        return *this;
+    }
+
+    bool operator==(const ClusterRole& other) const;
+
+    bool operator!=(const ClusterRole& other) const {
+        return !ClusterRole::operator==(other);
+    }
+
+private:
+    Value _value;
+};
+}  // namespace mongo

src/mongo/db/commands/rwc_defaults_commands.cpp

@@ -83,7 +83,8 @@ void assertNotStandaloneOrShardServer(OperationContext* opCtx, StringData cmdNam
 
     uassert(51301,
             str::stream() << "'" << cmdName << "' is not supported on shard nodes.",
-            serverGlobalParams.clusterRole != ClusterRole::ShardServer);
+            serverGlobalParams.clusterRole == ClusterRole::None ||
+                serverGlobalParams.clusterRole == ClusterRole::ConfigServer);
 }
 
 auto makeResponse(const ReadWriteConcernDefaults::RWConcernDefaultAndTime& rwcDefault,

src/mongo/db/mongod_main.cpp

@@ -56,6 +56,7 @@
 #include "mongo/db/catalog/health_log.h"
 #include "mongo/db/catalog/index_catalog.h"
 #include "mongo/db/catalog/index_key_validate.h"
+#include "mongo/db/catalog_shard_feature_flag_gen.h"
 #include "mongo/db/change_collection_expired_documents_remover.h"
 #include "mongo/db/change_stream_change_collection_manager.h"
 #include "mongo/db/change_stream_options_manager.h"
@@ -367,14 +368,18 @@ void registerPrimaryOnlyServices(ServiceContext* serviceContext) {
     if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
         services.push_back(std::make_unique<ReshardingCoordinatorService>(serviceContext));
         services.push_back(std::make_unique<ConfigsvrCoordinatorService>(serviceContext));
-    } else if (serverGlobalParams.clusterRole == ClusterRole::ShardServer) {
+    }
+
+    if (serverGlobalParams.clusterRole == ClusterRole::ShardServer) {
         services.push_back(std::make_unique<RenameCollectionParticipantService>(serviceContext));
         services.push_back(std::make_unique<ShardingDDLCoordinatorService>(serviceContext));
         services.push_back(std::make_unique<ReshardingDonorService>(serviceContext));
         services.push_back(std::make_unique<ReshardingRecipientService>(serviceContext));
         services.push_back(std::make_unique<TenantMigrationDonorService>(serviceContext));
         services.push_back(std::make_unique<repl::TenantMigrationRecipientService>(serviceContext));
-    } else {
+    }
+
+    if (serverGlobalParams.clusterRole == ClusterRole::None) {
         services.push_back(std::make_unique<TenantMigrationDonorService>(serviceContext));
         services.push_back(std::make_unique<repl::TenantMigrationRecipientService>(serviceContext));
         if (getGlobalReplSettings().isServerless()) {
@@ -674,7 +679,8 @@ ExitCode _initAndListen(ServiceContext* serviceContext, int listenPort) {
     }
 
     try {
-        if (serverGlobalParams.clusterRole != ClusterRole::ShardServer &&
+        if ((serverGlobalParams.clusterRole == ClusterRole::ConfigServer ||
+             serverGlobalParams.clusterRole == ClusterRole::None) &&
             replSettings.usingReplSets()) {
             ReadWriteConcernDefaults::get(startupOpCtx.get()->getServiceContext())
                 .refreshIfNecessary(startupOpCtx.get());
@@ -730,16 +736,23 @@ ExitCode _initAndListen(ServiceContext* serviceContext, int listenPort) {
                     uassertStatusOK(ShardingStateRecovery_DEPRECATED::recover(startupOpCtx.get()));
                 }
             }
-        } else if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
+        }
+
+        if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
             initializeGlobalShardingStateForMongoD(
                 startupOpCtx.get(), ShardId::kConfigServerId, ConnectionString::forLocal());
 
             ShardingCatalogManager::create(
                 startupOpCtx->getServiceContext(),
                 makeShardingTaskExecutor(executor::makeNetworkInterface("AddShard-TaskExecutor")));
 
-            Grid::get(startupOpCtx.get())->setShardingInitialized();
-        } else if (replSettings.usingReplSets()) {  // standalone replica set
+            if (!gFeatureFlagCatalogShard.isEnabledAndIgnoreFCV()) {
+                Grid::get(startupOpCtx.get())->setShardingInitialized();
+            }
+        }
+
+        if (serverGlobalParams.clusterRole == ClusterRole::None &&
+            replSettings.usingReplSets()) {  // standalone replica set
             // The keys client must use local read concern if the storage engine can't support
             // majority read concern.
             auto keysClientMustUseLocalReads =
@@ -862,10 +875,10 @@ ExitCode _initAndListen(ServiceContext* serviceContext, int listenPort) {
 
     // Set up the logical session cache
     LogicalSessionCacheServer kind = LogicalSessionCacheServer::kStandalone;
-    if (serverGlobalParams.clusterRole == ClusterRole::ShardServer) {
-        kind = LogicalSessionCacheServer::kSharded;
-    } else if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
+    if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
         kind = LogicalSessionCacheServer::kConfigServer;
+    } else if (serverGlobalParams.clusterRole == ClusterRole::ShardServer) {
+        kind = LogicalSessionCacheServer::kSharded;
     } else if (replSettings.usingReplSets()) {
         kind = LogicalSessionCacheServer::kReplicaSet;
     }
@@ -1207,14 +1220,21 @@ void setUpObservers(ServiceContext* serviceContext) {
         if (getGlobalReplSettings().isServerless()) {
             opObserverRegistry->addObserver(std::make_unique<ShardSplitDonorOpObserver>());
         }
-    } else if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
-        opObserverRegistry->addObserver(
-            std::make_unique<OpObserverImpl>(std::make_unique<OplogWriterImpl>()));
+    }
+
+    if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
+        if (!gFeatureFlagCatalogShard.isEnabledAndIgnoreFCV()) {
+            opObserverRegistry->addObserver(
+                std::make_unique<OpObserverImpl>(std::make_unique<OplogWriterImpl>()));
+        }
+
         opObserverRegistry->addObserver(std::make_unique<ConfigServerOpObserver>());
         opObserverRegistry->addObserver(std::make_unique<ReshardingOpObserver>());
         opObserverRegistry->addObserver(
             std::make_unique<analyze_shard_key::QueryAnalysisOpObserver>());
-    } else {
+    }
+
+    if (serverGlobalParams.clusterRole == ClusterRole::None) {
         opObserverRegistry->addObserver(
             std::make_unique<OpObserverImpl>(std::make_unique<OplogWriterImpl>()));
         opObserverRegistry->addObserver(std::make_unique<repl::TenantMigrationDonorOpObserver>());
@@ -1225,6 +1245,7 @@ void setUpObservers(ServiceContext* serviceContext) {
             opObserverRegistry->addObserver(std::make_unique<ShardSplitDonorOpObserver>());
         }
     }
+
     opObserverRegistry->addObserver(std::make_unique<AuthOpObserver>());
     opObserverRegistry->addObserver(
         std::make_unique<repl::PrimaryOnlyServiceOpObserver>(serviceContext));

src/mongo/db/s/query_analysis_coordinator.cpp

@@ -31,6 +31,7 @@
 
 #include "mongo/db/s/query_analysis_coordinator.h"
 
+#include "mongo/db/catalog_shard_feature_flag_gen.h"
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/logv2/log.h"
 #include "mongo/s/analyze_shard_key_documents_gen.h"
@@ -184,7 +185,10 @@ void QueryAnalysisCoordinator::onStartup(OperationContext* opCtx) {
     }
 
     {
-        invariant(_samplers.empty());
+        if (!gFeatureFlagCatalogShard.isEnabledAndIgnoreFCV()) {
+            invariant(_samplers.empty());
+        }
+
         auto minPingTime = _getMinLastPingTime();
         FindCommandRequest findRequest{MongosType::ConfigNS};
         findRequest.setFilter(BSON(MongosType::ping << BSON("$gte" << minPingTime)));