SERVER-53283 Remove code that patches up sharding metadata on FCV upgrade/downgrade to/from 4.9

8 files changed, 6 insertions, 818 deletions

diff --git a/src/mongo/db/s/config/configsvr_refine_collection_shard_key_command.cpp b/src/mongo/db/s/config/configsvr_refine_collection_shard_key_command.cpp
index ce1065ddb0c..67a8843e5e2 100644
--- a/src/mongo/db/s/config/configsvr_refine_collection_shard_key_command.cpp
+++ b/src/mongo/db/s/config/configsvr_refine_collection_shard_key_command.cpp
@@ -32,7 +32,6 @@
 #include "mongo/db/audit.h"
 #include "mongo/db/auth/authorization_session.h"
 #include "mongo/db/commands.h"
-#include "mongo/db/commands/feature_compatibility_version.h"
 #include "mongo/db/repl/repl_client_info.h"
 #include "mongo/db/s/config/sharding_catalog_manager.h"
 #include "mongo/db/s/shard_key_util.h"
@@ -60,14 +59,6 @@ public:
             uassert(ErrorCodes::InvalidOptions,
                     "_configsvrRefineCollectionShardKey must be called with majority writeConcern",
                     opCtx->getWriteConcern().wMode == WriteConcernOptions::kMajority);
-
-            // TODO (SERVER-53283): Delete this code when FCV 5.1 becomes the official one
-            FixedFCVRegion fcvRegion(opCtx);
-            uassert(ErrorCodes::ConflictingOperationInProgress,
-                    "Cannot refine collection shard key while the node is being upgraded or "
-                    "downgraded",
-                    !fcvRegion->isUpgradingOrDowngrading());
-
             _internalRun(opCtx);
         }
 
diff --git a/src/mongo/db/s/config/sharding_catalog_manager.cpp b/src/mongo/db/s/config/sharding_catalog_manager.cpp
index f91f3e89e12..1eb6949ae59 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager.cpp
+++ b/src/mongo/db/s/config/sharding_catalog_manager.cpp
@@ -61,7 +61,6 @@
 #include "mongo/s/grid.h"
 #include "mongo/s/write_ops/batched_command_request.h"
 #include "mongo/s/write_ops/batched_command_response.h"
-#include "mongo/stdx/unordered_map.h"
 #include "mongo/transport/service_entry_point.h"
 #include "mongo/util/log_and_backoff.h"
 
@@ -177,77 +176,7 @@ void abortTransaction(OperationContext* opCtx, TxnNumber txnNumber) {
     }
 }
 
-// Updates documents in the config db using DBDirectClient
-void updateConfigDocumentDBDirect(OperationContext* opCtx,
-                                  const mongo::NamespaceString& nss,
-                                  const BSONObj& query,
-                                  const BSONObj& update,
-                                  bool upsert,
-                                  bool multi) {
-    invariant(nss.db() == "config");
-
-    DBDirectClient client(opCtx);
-
-    write_ops::UpdateCommandRequest updateOp(nss, [&] {
-        write_ops::UpdateOpEntry u;
-        u.setQ(query);
-        u.setU(write_ops::UpdateModification::parseFromClassicUpdate(update));
-        u.setMulti(multi);
-        u.setUpsert(upsert);
-        return std::vector{u};
-    }());
-    updateOp.setWriteCommandRequestBase([] {
-        write_ops::WriteCommandRequestBase base;
-        base.setOrdered(false);
-        return base;
-    }());
-
-    auto commandResult =
-        client.runCommand(OpMsgRequest::fromDBAndBody(nss.db(), updateOp.toBSON({})));
-    uassertStatusOK([&] {
-        BatchedCommandResponse response;
-        std::string unusedErrmsg;
-        response.parseBSON(
-            commandResult->getCommandReply(),
-            &unusedErrmsg);  // Return value intentionally ignored, because response.toStatus() will
-                             // contain any errors in more detail
-        return response.toStatus();
-    }());
-    uassertStatusOK(getWriteConcernStatusFromCommandResult(commandResult->getCommandReply()));
-}
-
-Status createNsIndexesForConfigChunks(OperationContext* opCtx) {
-    const bool unique = true;
-    auto configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-
-    Status result = configShard->createIndexOnConfig(
-        opCtx, ChunkType::ConfigNS, BSON(ChunkType::ns() << 1 << ChunkType::min() << 1), unique);
-    if (!result.isOK()) {
-        return result.withContext("couldn't create ns_1_min_1 index on config db");
-    }
-
-    result = configShard->createIndexOnConfig(
-        opCtx,
-        ChunkType::ConfigNS,
-        BSON(ChunkType::ns() << 1 << ChunkType::shard() << 1 << ChunkType::min() << 1),
-        unique);
-    if (!result.isOK()) {
-        return result.withContext("couldn't create ns_1_shard_1_min_1 index on config db");
-    }
-
-    result =
-        configShard->createIndexOnConfig(opCtx,
-                                         ChunkType::ConfigNS,
-                                         BSON(ChunkType::ns() << 1 << ChunkType::lastmod() << 1),
-                                         unique);
-    if (!result.isOK()) {
-        return result.withContext("couldn't create ns_1_lastmod_1 index on config db");
-    }
-
-    return Status::OK();
-}
-
-Status createUuidIndexesForConfigChunks(OperationContext* opCtx) {
+Status createIndexesForConfigChunks(OperationContext* opCtx) {
     const bool unique = true;
     auto configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
     Status result = configShard->createIndexOnConfig(
@@ -279,46 +208,6 @@ Status createUuidIndexesForConfigChunks(OperationContext* opCtx) {
 
     return Status::OK();
 }
-
-/**
- * This step runs on FCV switch between 4.4 <-> 5.0, right after the shards have been told to enter
- * Phase 1 and after all the local chunks' format has been changed to contain both UUID and
- * Namespace.
- *
- * If isOnUpgrade is true, it will remove any config.chunks entries, which do not have UUID and if
- * it is false, it will remove those which do not have Namespace.
- */
-void removeIncompleteChunks(OperationContext* opCtx, bool isOnUpgrade) {
-    const auto catalogClient = Grid::get(opCtx)->catalogClient();
-
-    auto query = isOnUpgrade ? BSON(ChunkType::collectionUUID << BSON("$exists" << false))
-                             : BSON(ChunkType::ns << BSON("$exists" << false));
-    uassertStatusOK(catalogClient->removeConfigDocuments(
-        opCtx, ChunkType::ConfigNS, query, ShardingCatalogClient::kLocalWriteConcern));
-}
-
-// When building indexes for existing collections during FCV upgrade, use the createIndexes command
-// instead of Shard::createIndexesOnConfig, in order to leverage hybrid builds that do not require
-// to hold the collection lock in X_MODE for the duration of the build.
-// TODO SERVER-53283: Remove once 5.0 has been released.
-void createIndexesForFCVUpgradeDowngrade(OperationContext* opCtx,
-                                         const std::vector<BSONObj>& keysVector) {
-    DBDirectClient client(opCtx);
-    const auto indexSpecs = [&keysVector]() -> std::vector<BSONObj> {
-        std::vector<BSONObj> indexSpecs;
-        for (const auto& keys : keysVector) {
-            IndexSpec spec;
-            spec.addKeys(keys);
-            spec.unique(true);
-
-            indexSpecs.emplace_back(spec.toBSON());
-        }
-        return indexSpecs;
-    }();
-
-    client.createIndexes(ChunkType::ConfigNS.ns(), indexSpecs);
-}
-
 }  // namespace
 
 void ShardingCatalogManager::create(ServiceContext* serviceContext,
@@ -353,8 +242,7 @@ ShardingCatalogManager::ShardingCatalogManager(
       _executorForAddShard(std::move(addShardExecutor)),
       _kShardMembershipLock("shardMembershipLock"),
       _kChunkOpLock("chunkOpLock"),
-      _kZoneOpLock("zoneOpLock"),
-      _kDatabaseOpLock("databaseOpLock") {
+      _kZoneOpLock("zoneOpLock") {
     startup();
 }
 
@@ -473,16 +361,12 @@ Status ShardingCatalogManager::_initConfigIndexes(OperationContext* opCtx) {
     const bool unique = true;
     auto configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
 
-    // (Generic FCV reference): TODO SERVER-53283 Remove the outermost 'if' statement once 5.0 has
-    // branched out.
-    if (!serverGlobalParams.featureCompatibility.isUpgradingOrDowngrading()) {
-        const auto result = createUuidIndexesForConfigChunks(opCtx);
-        if (result != Status::OK()) {
-            return result;
-        }
+    Status result = createIndexesForConfigChunks(opCtx);
+    if (result != Status::OK()) {
+        return result;
     }
 
-    Status result = configShard->createIndexOnConfig(
+    result = configShard->createIndexOnConfig(
         opCtx,
         MigrationType::ConfigNS,
         BSON(MigrationType::ns() << 1 << MigrationType::min() << 1),
@@ -594,517 +478,6 @@ Status ShardingCatalogManager::setFeatureCompatibilityVersionOnShards(OperationC
     return Status::OK();
 }
 
-void ShardingCatalogManager::_removePre50LegacyMetadata(OperationContext* opCtx) {
-    const auto catalogClient = Grid::get(opCtx)->catalogClient();
-    // Delete all documents which have {dropped: true} from config.collections
-    uassertStatusOK(
-        catalogClient->removeConfigDocuments(opCtx,
-                                             CollectionType::ConfigNS,
-                                             BSON("dropped" << true),
-                                             ShardingCatalogClient::kLocalWriteConcern));
-
-    // Clear the {dropped:true} and {distributionMode:sharded} fields from config.collections
-    updateConfigDocumentDBDirect(opCtx,
-                                 CollectionType::ConfigNS,
-                                 {} /* query */,
-                                 BSON("$unset" << BSON("dropped"
-                                                       << "")
-                                               << "$unset"
-                                               << BSON("distributionMode"
-                                                       << "")),
-                                 false /* upsert */,
-                                 true /* multi */);
-}
-
-void ShardingCatalogManager::upgradeMetadataFor50Phase1(OperationContext* opCtx) {
-    LOGV2(5581200, "Starting metadata upgrade to 5.0 (phase 1)");
-
-    try {
-        _removePre50LegacyMetadata(opCtx);
-    } catch (const DBException& e) {
-        LOGV2(5276708, "Failed to upgrade sharding metadata: {error}", "error"_attr = e.toString());
-        throw;
-    }
-
-    try {
-        _upgradeDatabasesEntriesTo50(opCtx);
-        _upgradeCollectionsAndChunksEntriesTo50Phase1(opCtx);
-    } catch (const DBException& e) {
-        LOGV2(5581201,
-              "Failed to upgrade sharding metadata (phase 1): {error}",
-              "error"_attr = e.toString());
-        throw;
-    }
-
-    LOGV2(5581202, "Successfully upgraded metadata to 5.0 (phase 1)");
-}
-
-void ShardingCatalogManager::upgradeMetadataFor50Phase2(OperationContext* opCtx) {
-    LOGV2(5581206, "Starting metadata upgrade to 5.0 (phase 2)");
-
-    try {
-        _upgradeCollectionsAndChunksEntriesTo50Phase2(opCtx);
-    } catch (const DBException& e) {
-        LOGV2(5581207,
-              "Failed to upgrade sharding metadata (phase 2): {error}",
-              "error"_attr = e.toString());
-        throw;
-    }
-
-    LOGV2(5581208, "Successfully upgraded metadata to 5.0 (phase 2)");
-}
-
-void ShardingCatalogManager::downgradeMetadataToPre50Phase1(OperationContext* opCtx) {
-    LOGV2(5581203, "Starting metadata downgrade to pre 5.0 (phase 1)");
-
-    try {
-        _downgradeCollectionsAndChunksEntriesToPre50Phase1(opCtx);
-        _downgradeDatabasesEntriesToPre50(opCtx);
-    } catch (const DBException& e) {
-        LOGV2(5581204,
-              "Failed to downgrade sharding metadata (phase 1): {error}",
-              "error"_attr = e.toString());
-        throw;
-    }
-
-    LOGV2(5581205, "Successfully downgraded metadata to pre 5.0 (phase 1)");
-}
-
-void ShardingCatalogManager::downgradeMetadataToPre50Phase2(OperationContext* opCtx) {
-    LOGV2(5581209, "Starting metadata downgrade to pre 5.0 (phase 2)");
-
-    try {
-        _downgradeCollectionsAndChunksEntriesToPre50Phase2(opCtx);
-    } catch (const DBException& e) {
-        LOGV2(5581210,
-              "Failed to downgrade sharding metadata (phase 2): {error}",
-              "error"_attr = e.toString());
-        throw;
-    }
-
-    LOGV2(5581211, "Successfully downgraded metadata to pre 5.0 (phase 2)");
-}
-
-void ShardingCatalogManager::_upgradeDatabasesEntriesTo50(OperationContext* opCtx) {
-    LOGV2(5258802, "Starting upgrade of config.databases");
-
-    auto const catalogCache = Grid::get(opCtx)->catalogCache();
-    auto const configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-    const auto dbDocs =
-        uassertStatusOK(
-            configShard->exhaustiveFindOnConfig(
-                opCtx,
-                ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                repl::ReadConcernLevel::kLocalReadConcern,
-                DatabaseType::ConfigNS,
-                BSON(DatabaseType::version() + "." + DatabaseVersion::kTimestampFieldName
-                     << BSON("$exists" << false)),
-                BSONObj(),
-                boost::none))
-            .docs;
-
-    for (const auto& doc : dbDocs) {
-        const DatabaseType db = uassertStatusOK(DatabaseType::fromBSON(doc));
-        const auto name = db.getName();
-
-        auto now = VectorClock::get(opCtx)->getTime();
-        auto clusterTime = now.clusterTime().asTimestamp();
-
-        Lock::ExclusiveLock lock(opCtx->lockState(), _kDatabaseOpLock);
-        updateConfigDocumentDBDirect(
-            opCtx,
-            DatabaseType::ConfigNS,
-            BSON(DatabaseType::name << name),
-            BSON("$set" << BSON(DatabaseType::version() + "." + DatabaseVersion::kTimestampFieldName
-                                << clusterTime)),
-            false /* upsert */,
-            false /* multi*/);
-    }
-
-    // Wait until the last operation is majority-committed
-    WriteConcernResult ignoreResult;
-    const auto latestOpTime = repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp();
-    uassertStatusOK(waitForWriteConcern(
-        opCtx, latestOpTime, ShardingCatalogClient::kMajorityWriteConcern, &ignoreResult));
-
-    // Forcing a refresh of each DB on each shard
-    const auto allDBDocs = uassertStatusOK(configShard->exhaustiveFindOnConfig(
-                                               opCtx,
-                                               ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                                               repl::ReadConcernLevel::kLocalReadConcern,
-                                               DatabaseType::ConfigNS,
-                                               BSONObj(),
-                                               BSONObj(),
-                                               boost::none))
-                               .docs;
-    const auto shardIds = Grid::get(opCtx)->shardRegistry()->getAllShardIds(opCtx);
-    const auto fixedExecutor = Grid::get(_serviceContext)->getExecutorPool()->getFixedExecutor();
-    for (const auto& doc : allDBDocs) {
-        const DatabaseType db = uassertStatusOK(DatabaseType::fromBSON(doc));
-        const auto name = db.getName();
-
-        catalogCache->invalidateDatabaseEntry_LINEARIZABLE(name);
-        sharding_util::tellShardsToRefreshDatabase(opCtx, shardIds, name, fixedExecutor);
-    }
-
-    LOGV2(5258803, "Successfully upgraded config.databases");
-}
-
-void ShardingCatalogManager::_downgradeDatabasesEntriesToPre50(OperationContext* opCtx) {
-    LOGV2(5258806, "Starting downgrade of config.databases");
-
-    {
-        Lock::ExclusiveLock lock(opCtx->lockState(), _kDatabaseOpLock);
-        updateConfigDocumentDBDirect(
-            opCtx,
-            DatabaseType::ConfigNS,
-            {} /* query */,
-            BSON("$unset" << BSON(
-                     DatabaseType::version() + "." + DatabaseVersion::kTimestampFieldName << "")),
-            false /* upsert */,
-            true /* multi */);
-    }
-
-    auto const catalogCache = Grid::get(opCtx)->catalogCache();
-    auto const configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-    const auto dbDocs = uassertStatusOK(configShard->exhaustiveFindOnConfig(
-                                            opCtx,
-                                            ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                                            repl::ReadConcernLevel::kLocalReadConcern,
-                                            DatabaseType::ConfigNS,
-                                            BSONObj(),
-                                            BSONObj(),
-                                            boost::none))
-                            .docs;
-
-    // Wait until the last operation is majority-committed
-    WriteConcernResult ignoreResult;
-    const auto latestOpTime = repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp();
-    uassertStatusOK(waitForWriteConcern(
-        opCtx, latestOpTime, ShardingCatalogClient::kMajorityWriteConcern, &ignoreResult));
-
-    // Forcing a refresh of each DB on each shard
-    const auto shardIds = Grid::get(opCtx)->shardRegistry()->getAllShardIds(opCtx);
-    const auto fixedExecutor = Grid::get(_serviceContext)->getExecutorPool()->getFixedExecutor();
-    for (const auto& doc : dbDocs) {
-        const DatabaseType db = uassertStatusOK(DatabaseType::fromBSON(doc));
-        const auto name = db.getName();
-
-        catalogCache->invalidateDatabaseEntry_LINEARIZABLE(name);
-        sharding_util::tellShardsToRefreshDatabase(opCtx, shardIds, name, fixedExecutor);
-    }
-
-    LOGV2(5258807, "Successfully downgraded config.databases");
-}
-
-void ShardingCatalogManager::_upgradeCollectionsAndChunksEntriesTo50Phase1(
-    OperationContext* opCtx) {
-    LOGV2(5276700, "Starting upgrade of config.collections and config.chunks (phase 1)");
-
-    auto const catalogCache = Grid::get(opCtx)->catalogCache();
-    auto const configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-
-    auto collectionDocs =
-        uassertStatusOK(
-            configShard->exhaustiveFindOnConfig(
-                opCtx,
-                ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                repl::ReadConcernLevel::kLocalReadConcern,
-                CollectionType::ConfigNS,
-                BSONObj(BSON(CollectionType::kTimestampFieldName << BSON("$exists" << false))),
-                BSONObj(),
-                boost::none))
-            .docs;
-
-    stdx::unordered_map<NamespaceString, Timestamp> timestampMap;
-
-    // Set timestamp and uuid for all chunks in all collections
-    for (const auto& doc : collectionDocs) {
-        const CollectionType coll(doc);
-        const auto uuid = coll.getUuid();
-        const auto nss = coll.getNss();
-
-        uassert(547900,
-                str::stream() << "The 'allowMigrations' field of the " << nss
-                              << " collection must be true",
-                coll.getAllowMigrations());
-
-        const auto now = VectorClock::get(opCtx)->getTime();
-        const auto newTimestamp = now.clusterTime().asTimestamp();
-        timestampMap.emplace(nss, newTimestamp);
-
-        // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
-        // migrations.
-        Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
-
-        updateConfigDocumentDBDirect(
-            opCtx,
-            ChunkType::ConfigNS,
-            BSON(ChunkType::ns(nss.ns())) /* query */,
-            BSON("$set" << BSON(ChunkType::timestamp(newTimestamp)
-                                << ChunkType::collectionUUID() << uuid)) /* update */,
-            false /* upsert */,
-            true /* multi */);
-    }
-
-    removeIncompleteChunks(opCtx, true /* isOnUpgrade */);
-
-    // Create uuid_* indexes for config.chunks
-    createIndexesForFCVUpgradeDowngrade(
-        opCtx,
-        {BSON(ChunkType::collectionUUID << 1 << ChunkType::min() << 1),
-         BSON(ChunkType::collectionUUID << 1 << ChunkType::shard() << 1 << ChunkType::min() << 1),
-         BSON(ChunkType::collectionUUID << 1 << ChunkType::lastmod() << 1)});
-
-    // Set timestamp for all collections in config.collections
-    for (const auto& doc : collectionDocs) {
-        // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
-        // migrations.
-        Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
-
-        const CollectionType coll(doc);
-        const auto nss = coll.getNss();
-
-        updateConfigDocumentDBDirect(opCtx,
-                                     CollectionType::ConfigNS,
-                                     BSON(CollectionType::kNssFieldName << nss.ns()) /* query */,
-                                     BSON("$set" << BSON(CollectionType::kTimestampFieldName
-                                                         << timestampMap.at(nss))) /* update */,
-                                     false /* upsert */,
-                                     false /* multi */);
-    }
-
-    // Wait until the last operation is majority-committed
-    WriteConcernResult ignoreResult;
-    const auto latestOpTime = repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp();
-    uassertStatusOK(waitForWriteConcern(
-        opCtx, latestOpTime, ShardingCatalogClient::kMajorityWriteConcern, &ignoreResult));
-
-    // Forcing a refresh of each collection on each shard
-    const auto allCollectionDocs =
-        uassertStatusOK(
-            configShard->exhaustiveFindOnConfig(opCtx,
-                                                ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                                                repl::ReadConcernLevel::kLocalReadConcern,
-                                                CollectionType::ConfigNS,
-                                                BSONObj(),
-                                                BSONObj(),
-                                                boost::none))
-            .docs;
-    const auto shardIds = Grid::get(opCtx)->shardRegistry()->getAllShardIds(opCtx);
-    const auto fixedExecutor = Grid::get(_serviceContext)->getExecutorPool()->getFixedExecutor();
-    for (const auto& doc : allCollectionDocs) {
-        const CollectionType coll(doc);
-        const auto nss = coll.getNss();
-        catalogCache->invalidateCollectionEntry_LINEARIZABLE(nss);
-        try {
-            sharding_util::tellShardsToRefreshCollection(opCtx, shardIds, nss, fixedExecutor);
-        } catch (const ExceptionFor<ErrorCodes::ConflictingOperationInProgress>& ex) {
-            // Collection is being dropped by a legacy-path dropCollection
-            LOGV2(5617300,
-                  "Failed to refresh collection on shards after metadata patch-up",
-                  "nss"_attr = nss,
-                  "exception"_attr = redact(ex));
-        }
-    }
-
-    // Drop ns_* indexes of config.chunks
-    {
-        DBDirectClient client(opCtx);
-
-        const bool includeBuildUUIDs = false;
-        const int options = 0;
-        auto indexes = client.getIndexSpecs(ChunkType::ConfigNS, includeBuildUUIDs, options);
-        BSONArrayBuilder indexNamesToDrop;
-        for (const auto& index : indexes) {
-            const auto indexName = index.getStringField("name");
-            if (indexName == "ns_1_min_1"_sd || indexName == "ns_1_shard_1_min_1"_sd ||
-                indexName == "ns_1_lastmod_1"_sd) {
-                indexNamesToDrop.append(indexName);
-            }
-        }
-
-        BSONObj info;
-        if (!client.runCommand(ChunkType::ConfigNS.db().toString(),
-                               BSON("dropIndexes" << ChunkType::ConfigNS.coll() << "index"
-                                                  << indexNamesToDrop.arr()),
-                               info))
-            uassertStatusOK(getStatusFromCommandResult(info));
-    }
-
-    LOGV2(5276701, "Successfully upgraded config.collections and config.chunks (phase 1)");
-}
-
-void ShardingCatalogManager::_upgradeCollectionsAndChunksEntriesTo50Phase2(
-    OperationContext* opCtx) {
-    LOGV2(5276706, "Starting upgrade of config.chunks (phase 2)");
-
-    // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
-    // migrations.
-    Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
-
-    // Unset ns, epoch and timestamp for all chunks on config.chunks
-    updateConfigDocumentDBDirect(
-        opCtx,
-        ChunkType::ConfigNS,
-        {} /* query */,
-        BSON("$unset" << BSON(ChunkType::ns("") << ChunkType::epoch() << ""
-                                                << ChunkType::timestamp() << "")) /* update */,
-        false /* upsert */,
-        true /* multi */);
-
-    LOGV2(5276707, "Successfully upgraded config.chunks (phase 2)");
-}
-
-void ShardingCatalogManager::_downgradeCollectionsAndChunksEntriesToPre50Phase1(
-    OperationContext* opCtx) {
-    LOGV2(5276702, "Starting downgrade of config.collections and config.chunks (phase 1)");
-
-    auto const catalogCache = Grid::get(opCtx)->catalogCache();
-    auto const configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-
-    auto collectionDocs =
-        uassertStatusOK(
-            configShard->exhaustiveFindOnConfig(
-                opCtx,
-                ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                repl::ReadConcernLevel::kLocalReadConcern,
-                CollectionType::ConfigNS,
-                BSONObj(BSON(CollectionType::kTimestampFieldName << BSON("$exists" << true))),
-                BSONObj(),
-                boost::none))
-            .docs;
-
-    // Set ns on all chunks
-    for (const auto& doc : collectionDocs) {
-        // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
-        // migrations.
-        Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
-
-        const CollectionType coll(doc);
-        const auto uuid = coll.getUuid();
-        const auto nss = coll.getNss();
-
-        uassert(547901,
-                str::stream() << "The 'allowMigrations' field of the " << nss
-                              << " collection must be true",
-                coll.getAllowMigrations());
-
-        updateConfigDocumentDBDirect(
-            opCtx,
-            ChunkType::ConfigNS,
-            BSON(ChunkType::collectionUUID << uuid) /* query */,
-            BSON("$set" << BSON(ChunkType::ns(nss.ns())
-                                << ChunkType::epoch() << coll.getEpoch())) /* update */,
-            false /* upsert */,
-            true /* multi */);
-    }
-
-    removeIncompleteChunks(opCtx, false /* isOnUpgrade */);
-
-    // Create ns_* indexes for config.chunks
-    createIndexesForFCVUpgradeDowngrade(
-        opCtx,
-        {BSON(ChunkType::ns << 1 << ChunkType::min() << 1),
-         BSON(ChunkType::ns << 1 << ChunkType::shard() << 1 << ChunkType::min() << 1),
-         BSON(ChunkType::ns << 1 << ChunkType::lastmod() << 1)});
-
-    // Unset the timestamp field on all collections
-    {
-        // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
-        // migrations.
-        Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
-
-        updateConfigDocumentDBDirect(
-            opCtx,
-            CollectionType::ConfigNS,
-            {} /* query */,
-            BSON("$unset" << BSON(CollectionType::kTimestampFieldName << "")) /* update */,
-            false /* upsert */,
-            true /* multi */);
-    }
-
-    // Wait until the last operation is majority-committed
-    WriteConcernResult ignoreResult;
-    const auto latestOpTime = repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp();
-    uassertStatusOK(waitForWriteConcern(
-        opCtx, latestOpTime, ShardingCatalogClient::kMajorityWriteConcern, &ignoreResult));
-
-    // Forcing a refresh of each collection on each shard
-    const auto allCollectionDocs =
-        uassertStatusOK(
-            configShard->exhaustiveFindOnConfig(opCtx,
-                                                ReadPreferenceSetting{ReadPreference::PrimaryOnly},
-                                                repl::ReadConcernLevel::kLocalReadConcern,
-                                                CollectionType::ConfigNS,
-                                                BSONObj(),
-                                                BSONObj(),
-                                                boost::none))
-            .docs;
-    const auto shardIds = Grid::get(opCtx)->shardRegistry()->getAllShardIds(opCtx);
-    const auto fixedExecutor = Grid::get(_serviceContext)->getExecutorPool()->getFixedExecutor();
-    for (const auto& doc : allCollectionDocs) {
-        const CollectionType coll(doc);
-        const auto nss = coll.getNss();
-        catalogCache->invalidateCollectionEntry_LINEARIZABLE(nss);
-        try {
-            sharding_util::tellShardsToRefreshCollection(opCtx, shardIds, nss, fixedExecutor);
-        } catch (const ExceptionFor<ErrorCodes::ConflictingOperationInProgress>& ex) {
-            // Collection is being dropped by a legacy-path dropCollection
-            LOGV2(5617301,
-                  "Failed to refresh collection on shards after metadata patch-up",
-                  "nss"_attr = nss,
-                  "exception"_attr = redact(ex));
-        }
-    }
-
-    // Drop uuid_* indexes for config.chunks
-    {
-        DBDirectClient client(opCtx);
-
-        const bool includeBuildUUIDs = false;
-        const int options = 0;
-        auto indexes = client.getIndexSpecs(ChunkType::ConfigNS, includeBuildUUIDs, options);
-        BSONArrayBuilder indexNamesToDrop;
-        for (const auto& index : indexes) {
-            const auto indexName = index.getStringField("name");
-            if (indexName == "uuid_1_min_1"_sd || indexName == "uuid_1_shard_1_min_1"_sd ||
-                indexName == "uuid_1_lastmod_1"_sd) {
-                indexNamesToDrop.append(indexName);
-            }
-        }
-
-        BSONObj info;
-        if (!client.runCommand(ChunkType::ConfigNS.db().toString(),
-                               BSON("dropIndexes" << ChunkType::ConfigNS.coll() << "index"
-                                                  << indexNamesToDrop.arr()),
-                               info))
-            uassertStatusOK(getStatusFromCommandResult(info));
-    }
-
-    LOGV2(5276703, "Successfully downgraded config.collections and config.chunks (phase 1)");
-}
-
-void ShardingCatalogManager::_downgradeCollectionsAndChunksEntriesToPre50Phase2(
-    OperationContext* opCtx) {
-    LOGV2(5276709, "Starting downgrade of config.chunks (phase 2)");
-
-    // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
-    // migrations.
-    Lock::ExclusiveLock lk(opCtx->lockState(), _kChunkOpLock);
-
-    // Unset the uuid for all chunks on config.chunks
-    updateConfigDocumentDBDirect(
-        opCtx,
-        ChunkType::ConfigNS,
-        {} /* query */,
-        BSON("$unset" << BSON(ChunkType::collectionUUID() << "")) /* update */,
-        false /* upsert */,
-        true /* multi */);
-
-    LOGV2(5276710, "Successfully downgraded config.chunks (phase 2)");
-}
-
 StatusWith<bool> ShardingCatalogManager::_isShardRequiredByZoneStillInUse(
     OperationContext* opCtx,
     const ReadPreferenceSetting& readPref,
diff --git a/src/mongo/db/s/config/sharding_catalog_manager.h b/src/mongo/db/s/config/sharding_catalog_manager.h
index f357d88d8d8..9ff86dee0ca 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager.h
+++ b/src/mongo/db/s/config/sharding_catalog_manager.h
@@ -427,42 +427,6 @@ public:
      */
     Status setFeatureCompatibilityVersionOnShards(OperationContext* opCtx, const BSONObj& cmdObj);
 
-    /**
-     * Patches-up persistent metadata for 5.0.
-     *
-     * It shall be called when upgrading to 5.0 or newer versions, when shards are in phase-1 of the
-     * setFCV protocol.
-     * TODO SERVER-53283: Remove once 5.0 has been released.
-     */
-    void upgradeMetadataFor50Phase1(OperationContext* opCtx);
-
-    /**
-     * Patches-up persistent metadata for 5.0.
-     *
-     * It shall be called when upgrading to 5.0 or newer versions, when shards are in phase-2 of the
-     * setFCV protocol.
-     * TODO SERVER-53283: Remove once 5.0 has been released.
-     */
-    void upgradeMetadataFor50Phase2(OperationContext* opCtx);
-
-    /**
-     * Patches-up persistent metadata for downgrade from 5.0.
-     *
-     * It shall be called when downgrading from 5.0 to an earlier version, when shards are in
-     * phase-1 of the setFCV protocol.
-     * TODO SERVER-53283: Remove once 5.0 has been released.
-     */
-    void downgradeMetadataToPre50Phase1(OperationContext* opCtx);
-
-    /**
-     * Patches-up persistent metadata for downgrade from 5.0.
-     *
-     * It shall be called when downgrading from 5.0 to an earlier version, when shards are in
-     * phase-2 of the setFCV protocol.
-     * TODO SERVER-53283: Remove once 5.0 has been released.
-     */
-    void downgradeMetadataToPre50Phase2(OperationContext* opCtx);
-
     /*
      * Rename collection metadata as part of a renameCollection operation.
      *
@@ -598,70 +562,6 @@ private:
                                                       const std::string& shardName,
                                                       const std::string& zoneName);
 
-    /**
-     * Removes all entries from the config server's config.collections where 'dropped' is true.
-     *
-     * Before 5.0, when a collection was dropped, its entry in config.collections remained, tagged
-     * as 'dropped: true'. As those are no longer needed, this method cleans up the leftover
-     * metadata.
-     *
-     * It shall be called when upgrading to 5.0 or newer versions.
-     *
-     * TODO SERVER-53283: Remove once 5.0 has becomes last-lts.
-     */
-    void _removePre50LegacyMetadata(OperationContext* opCtx);
-
-    /**
-     * Creates a 'version.timestamp' for each one of the entries in the config server's
-     * config.databases where it didn't already exist before.
-     *
-     * TODO SERVER-53283: Remove once 5.0 becomes last-lts.
-     */
-    void _upgradeDatabasesEntriesTo50(OperationContext* opCtx);
-
-    /**
-     * Downgrades the config.databases entries to prior 4.9 version. More specifically, it removes
-     * the 'version.timestamp' field from all the documents in config.databases.
-     *
-     * TODO SERVER-53283: Remove once 5.0 becomes last-lts.
-     */
-    void _downgradeDatabasesEntriesToPre50(OperationContext* opCtx);
-
-    /**
-     * For each one of the entries in config.collections where there is no 'timestamp':
-     * - Patches-up the entries in config.chunks to set their 'collectionUUID' and 'timestamp'
-     * fields.
-     * - Creates a 'timestamp' in its entry in config.collections.
-     * , and builds the uuid_* indexes and drops the ns_* indexes on config.chunks.
-     *
-     * TODO SERVER-53283: Remove once 5.0 becomes last-lts.
-     */
-    void _upgradeCollectionsAndChunksEntriesTo50Phase1(OperationContext* opCtx);
-
-    /**
-     * Unsets the 'ns' field from all documents in config.chunks
-     *
-     * TODO SERVER-53283: Remove once 5.0 becomes last-lts.
-     */
-    void _upgradeCollectionsAndChunksEntriesTo50Phase2(OperationContext* opCtx);
-
-    /**
-     * For each one of the entries in config.collections where there is a 'timestamp':
-     * - Patches-up the entries in config.chunks to set their 'ns' field.
-     * - Unsets the 'timestamp' field from its entry in config.collections.
-     * , and builds the ns_* indexes and drops the uuid_* indexes on config.chunks.
-     *
-     * TODO SERVER-53283: Remove once 5.0 becomes last-lts.
-     */
-    void _downgradeCollectionsAndChunksEntriesToPre50Phase1(OperationContext* opCtx);
-
-    /**
-     * Unsets the 'collectionUUID' and 'timestamp' fields from all documents in config.chunks
-     *
-     * TODO SERVER-53283: Remove once 5.0 becomes last-lts.
-     */
-    void _downgradeCollectionsAndChunksEntriesToPre50Phase2(OperationContext* opCtx);
-
     // The owning service context
     ServiceContext* const _serviceContext;
 
@@ -714,16 +614,6 @@ private:
      * taking this.
      */
     Lock::ResourceMutex _kZoneOpLock;
-
-    /**
-     * Lock for local database operations. This should be acquired when executing
-     * 'commitMovePrimary' and 'setFeatureCompatibilityVersion' commands which affect the
-     * config.databases collection. No other locks should be held when locking this. If an operation
-     * needs to take database locks (for example to write to a local collection) those locks should
-     * be taken after taking this.
-     * TODO (SERVER-53283): Remove once version 5.0 has been released.
-     */
-    Lock::ResourceMutex _kDatabaseOpLock;
 };
 
 }  // namespace mongo
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 6f9584d4929..4d204afce63 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
@@ -39,7 +39,6 @@
 #include "mongo/client/connection_string.h"
 #include "mongo/client/read_preference.h"
 #include "mongo/db/catalog_raii.h"
-#include "mongo/db/commands/feature_compatibility_version.h"
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/db/logical_session_cache.h"
 #include "mongo/db/namespace_string.h"
@@ -68,8 +67,6 @@
 namespace mongo {
 namespace {
 
-using FeatureCompatibilityParams = ServerGlobalParams::FeatureCompatibility;
-
 MONGO_FAIL_POINT_DEFINE(migrationCommitVersionError);
 MONGO_FAIL_POINT_DEFINE(migrateCommitInvalidChunkQuery);
 MONGO_FAIL_POINT_DEFINE(skipExpiringOldChunkHistory);
@@ -1043,15 +1040,6 @@ StatusWith<BSONObj> ShardingCatalogManager::commitChunkMigration(
     const ShardId& toShard,
     const boost::optional<Timestamp>& validAfter) {
 
-    // TODO(SERVER-53283): Remove the logic around fcvRegion to re-enable
-    // the concurrent execution of moveChunk() and setFCV().
-    FixedFCVRegion fcvRegion(opCtx);
-    uassert(ErrorCodes::ConflictingOperationInProgress,
-            "Cannot commit a chunk migration request "
-            "while the cluster is being upgraded or downgraded",
-            !fcvRegion->isUpgradingOrDowngrading());
-
-
     auto const configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
 
     // Must hold the shard lock until the entire commit finishes to serialize with removeShard.
diff --git a/src/mongo/db/s/sharding_ddl_coordinator_service.cpp b/src/mongo/db/s/sharding_ddl_coordinator_service.cpp
index bf21a715361..7e239e6d2a9 100644
--- a/src/mongo/db/s/sharding_ddl_coordinator_service.cpp
+++ b/src/mongo/db/s/sharding_ddl_coordinator_service.cpp
@@ -96,12 +96,6 @@ ShardingDDLCoordinatorService* ShardingDDLCoordinatorService::getService(Operati
 std::shared_ptr<ShardingDDLCoordinatorService::Instance>
 ShardingDDLCoordinatorService::constructInstance(BSONObj initialState) {
     auto coord = constructShardingDDLCoordinatorInstance(this, std::move(initialState));
-
-    {
-        stdx::lock_guard lg(_completionMutex);
-        ++_numActiveCoordinators;
-    }
-
     coord->getConstructionCompletionFuture()
         .thenRunOn(getInstanceCleanupExecutor())
         .getAsync([this](auto status) {
@@ -115,27 +109,9 @@ ShardingDDLCoordinatorService::constructInstance(BSONObj initialState) {
                 _recoveredCV.notify_all();
             }
         });
-
-    coord->getCompletionFuture()
-        .thenRunOn(getInstanceCleanupExecutor())
-        .getAsync([this](auto status) {
-            stdx::lock_guard lg(_completionMutex);
-            if (--_numActiveCoordinators == 0) {
-                _completedCV.notify_all();
-            }
-        });
-
     return coord;
 }
 
-void ShardingDDLCoordinatorService::waitForAllCoordinatorsToComplete(
-    OperationContext* opCtx) const {
-    _waitForRecoveryCompletion(opCtx);
-    stdx::unique_lock lk(_completionMutex);
-    opCtx->waitForConditionOrInterrupt(
-        _completedCV, lk, [this]() { return _numActiveCoordinators == 0; });
-}
-
 
 void ShardingDDLCoordinatorService::_afterStepDown() {
     stdx::lock_guard lg(_mutex);
diff --git a/src/mongo/db/s/sharding_ddl_coordinator_service.h b/src/mongo/db/s/sharding_ddl_coordinator_service.h
index 3f0163ae416..564f3821654 100644
--- a/src/mongo/db/s/sharding_ddl_coordinator_service.h
+++ b/src/mongo/db/s/sharding_ddl_coordinator_service.h
@@ -63,9 +63,6 @@ public:
 
     std::shared_ptr<Instance> getOrCreateInstance(OperationContext* opCtx, BSONObj initialState);
 
-    // TODO SERVER-53283 remove the following function after 5.0 became last LTS
-    void waitForAllCoordinatorsToComplete(OperationContext* opCtx) const;
-
 private:
     ExecutorFuture<void> _rebuildService(std::shared_ptr<executor::ScopedTaskExecutor> executor,
                                          const CancellationToken& token) override;
@@ -74,12 +71,6 @@ private:
     void _afterStepDown() override;
     size_t _countCoordinatorDocs(OperationContext* opCtx);
 
-    // TODO SERVER-53283 remove the following 3 variables after 5.0 became last LTS
-    mutable Mutex _completionMutex =
-        MONGO_MAKE_LATCH("ShardingDDLCoordinatorService::_completionMutex");
-    size_t _numActiveCoordinators{0};
-    mutable stdx::condition_variable _completedCV;
-
     mutable Mutex _mutex = MONGO_MAKE_LATCH("ShardingDDLCoordinatorService::_mutex");
 
     // When the node stepDown the state is set to kPaused and all the new DDL operation will be
diff --git a/src/mongo/db/s/sharding_util.cpp b/src/mongo/db/s/sharding_util.cpp
index 351da27f49c..26c8da56f8c 100644
--- a/src/mongo/db/s/sharding_util.cpp
+++ b/src/mongo/db/s/sharding_util.cpp
@@ -37,7 +37,6 @@
 #include "mongo/db/commands.h"
 #include "mongo/logv2/log.h"
 #include "mongo/s/async_requests_sender.h"
-#include "mongo/s/request_types/flush_database_cache_updates_gen.h"
 #include "mongo/s/request_types/flush_routing_table_cache_updates_gen.h"
 
 namespace mongo {
@@ -56,17 +55,6 @@ void tellShardsToRefreshCollection(OperationContext* opCtx,
     sendCommandToShards(opCtx, NamespaceString::kAdminDb, cmdObj, shardIds, executor);
 }
 
-void tellShardsToRefreshDatabase(OperationContext* opCtx,
-                                 const std::vector<ShardId>& shardIds,
-                                 const std::string& dbName,
-                                 const std::shared_ptr<executor::TaskExecutor>& executor) {
-    auto cmd = _flushDatabaseCacheUpdatesWithWriteConcern(dbName);
-    cmd.setSyncFromConfig(true);
-    cmd.setDbName(dbName);
-    auto cmdObj = CommandHelpers::appendMajorityWriteConcern(cmd.toBSON({}));
-    sendCommandToShards(opCtx, NamespaceString::kAdminDb, cmdObj, shardIds, executor);
-}
-
 void sendCommandToShards(OperationContext* opCtx,
                          StringData dbName,
                          const BSONObj& command,
diff --git a/src/mongo/db/s/sharding_util.h b/src/mongo/db/s/sharding_util.h
index 10b0c270edb..684568b0214 100644
--- a/src/mongo/db/s/sharding_util.h
+++ b/src/mongo/db/s/sharding_util.h
@@ -49,15 +49,6 @@ void tellShardsToRefreshCollection(OperationContext* opCtx,
                                    const std::shared_ptr<executor::TaskExecutor>& executor);
 
 /**
- * Sends _flushDatabaseCacheUpdatesWithWriteConcern to a list of shards. Throws if one of the
- * shards fails to refresh.
- */
-void tellShardsToRefreshDatabase(OperationContext* opCtx,
-                                 const std::vector<ShardId>& shardIds,
-                                 const std::string& dbName,
-                                 const std::shared_ptr<executor::TaskExecutor>& executor);
-
-/**
  * Generic utility to send a command to a list of shards. Throws if one of the commands fails.
  */
 void sendCommandToShards(OperationContext* opCtx,