SERVER-53861: Implement stop migrations procedure for DDL operations

3 files changed, 165 insertions, 0 deletions

diff --git a/src/mongo/db/s/config/configsvr_set_allow_migrations_command.cpp b/src/mongo/db/s/config/configsvr_set_allow_migrations_command.cpp
new file mode 100644
index 00000000000..8ab105f72e6
--- /dev/null
+++ b/src/mongo/db/s/config/configsvr_set_allow_migrations_command.cpp
@@ -0,0 +1,105 @@
+/**
+ *    Copyright (C) 2021-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.
+ */
+
+#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kSharding
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/auth/authorization_session.h"
+#include "mongo/db/commands.h"
+#include "mongo/db/s/config/sharding_catalog_manager.h"
+#include "mongo/s/request_types/set_allow_migrations_gen.h"
+
+namespace mongo {
+namespace {
+
+class ConfigsvrSetAllowMigrationsCommand final
+    : public TypedCommand<ConfigsvrSetAllowMigrationsCommand> {
+public:
+    using Request = ConfigsvrSetAllowMigrations;
+
+    class Invocation final : public InvocationBase {
+    public:
+        using InvocationBase::InvocationBase;
+
+        void typedRun(OperationContext* opCtx) {
+            const NamespaceString& nss = ns();
+
+            uassert(ErrorCodes::IllegalOperation,
+                    "_configsvrSetAllowMigrations can only be run on config servers",
+                    serverGlobalParams.clusterRole == ClusterRole::ConfigServer);
+            uassert(ErrorCodes::InvalidOptions,
+                    "_configsvrSetAllowMigrations must be called with majority writeConcern",
+                    opCtx->getWriteConcern().wMode == WriteConcernOptions::kMajority);
+
+            // Set the operation context read concern level to local for reads into the config
+            // database.
+            repl::ReadConcernArgs::get(opCtx) =
+                repl::ReadConcernArgs(repl::ReadConcernLevel::kLocalReadConcern);
+
+            const auto allowMigrations = request().getAllowMigrations();
+
+            ShardingCatalogManager::get(opCtx)->setAllowMigrationsAndBumpOneChunk(
+                opCtx, nss, allowMigrations);
+        }
+
+    private:
+        NamespaceString ns() const override {
+            return request().getCommandParameter();
+        }
+
+        bool supportsWriteConcern() const override {
+            return true;
+        }
+
+        void doCheckAuthorization(OperationContext* opCtx) const override {
+            uassert(ErrorCodes::Unauthorized,
+                    "Unauthorized",
+                    AuthorizationSession::get(opCtx->getClient())
+                        ->isAuthorizedForActionsOnResource(ResourcePattern::forClusterResource(),
+                                                           ActionType::internal));
+        }
+    };
+
+    std::string help() const override {
+        return "Internal command, which is exported by the sharding config server. Do not call "
+               "directly. Sets the allowMigrations flag on the specified collection.";
+    }
+
+    bool adminOnly() const override {
+        return true;
+    }
+
+    AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
+        return AllowedOnSecondary::kNever;
+    }
+} configsvrSetAllowMigrationsCmd;
+
+}  // namespace
+}  // namespace mongo
diff --git a/src/mongo/db/s/config/sharding_catalog_manager.h b/src/mongo/db/s/config/sharding_catalog_manager.h
index 9de828a0b46..7413e595e0d 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager.h
+++ b/src/mongo/db/s/config/sharding_catalog_manager.h
@@ -301,6 +301,14 @@ public:
                           const NamespaceString& nss,
                           const BSONObj& minKey);
 
+    /**
+     * In a transaction, sets the 'allowMigrations' to the requested state and bumps the collection
+     * version.
+     */
+    void setAllowMigrationsAndBumpOneChunk(OperationContext* opCtx,
+                                           const NamespaceString& nss,
+                                           bool allowMigrations);
+
     //
     // Database Operations
     //
diff --git a/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp b/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp
index 811d9e9cc66..f4a1d7c5349 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp
+++ b/src/mongo/db/s/config/sharding_catalog_manager_chunk_operations.cpp
@@ -45,6 +45,7 @@
 #include "mongo/db/operation_context.h"
 #include "mongo/db/repl/repl_client_info.h"
 #include "mongo/db/s/sharding_logging.h"
+#include "mongo/db/s/sharding_util.h"
 #include "mongo/db/server_options.h"
 #include "mongo/db/snapshot_window_options_gen.h"
 #include "mongo/db/transaction_participant_gen.h"
@@ -1453,4 +1454,55 @@ void ShardingCatalogManager::splitOrMarkJumbo(OperationContext* opCtx,
     }
 }
 
+void ShardingCatalogManager::setAllowMigrationsAndBumpOneChunk(OperationContext* opCtx,
+                                                               const NamespaceString& nss,
+                                                               bool allowMigrations) {
+    std::set<ShardId> shardsIds;
+    {
+        // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
+        // migrations
+        Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
+
+        const auto cm = uassertStatusOK(
+            Grid::get(opCtx)->catalogCache()->getShardedCollectionRoutingInfoWithRefresh(opCtx,
+                                                                                         nss));
+        cm.getAllShardIds(&shardsIds);
+        withTransaction(
+            opCtx, CollectionType::ConfigNS, [&](OperationContext* opCtx, TxnNumber txnNumber) {
+                // Update the 'allowMigrations' field. An unset 'allowMigrations' field implies
+                // 'true'. To ease backwards compatibility we omit 'allowMigrations' instead of
+                // setting it explicitly to 'true'.
+                const auto update = allowMigrations
+                    ? BSON("$unset" << BSON(CollectionType::kAllowMigrationsFieldName << ""))
+                    : BSON("$set" << BSON(CollectionType::kAllowMigrationsFieldName << false));
+
+                writeToConfigDocumentInTxn(
+                    opCtx,
+                    CollectionType::ConfigNS,
+                    BatchedCommandRequest::buildUpdateOp(
+                        CollectionType::ConfigNS,
+                        BSON(CollectionType::kNssFieldName << nss.ns()) /* query */,
+                        update /* update */,
+                        false /* upsert */,
+                        false /* multi */),
+                    txnNumber);
+
+                // Bump the chunk version for one single chunk
+                invariant(!shardsIds.empty());
+                bumpMajorVersionOneChunkPerShard(opCtx, nss, txnNumber, {*shardsIds.begin()});
+            });
+
+        // From now on migrations are not allowed anymore, so it is not possible that new shards
+        // will own chunks for this collection.
+    }
+
+    // Trigger a refresh on each shard containing chunks for this collection.
+    const auto executor = Grid::get(opCtx)->getExecutorPool()->getFixedExecutor();
+    sharding_util::tellShardsToRefreshCollection(
+        opCtx,
+        {std::make_move_iterator(shardsIds.begin()), std::make_move_iterator(shardsIds.end())},
+        nss,
+        executor);
+}
+
 }  // namespace mongo