diff --git a/includes/ServiceWiring.php b/includes/ServiceWiring.php
index 6a3951403ac..a3fe093ba5e 100644
--- a/includes/ServiceWiring.php
+++ b/includes/ServiceWiring.php
@@ -104,6 +104,7 @@ use Wikimedia\DependencyStore\KeyValueDependencyStore;
 use Wikimedia\DependencyStore\SqlModuleDependencyStore;
 use Wikimedia\Message\IMessageFormatterFactory;
 use Wikimedia\ObjectFactory;
+use Wikimedia\Services\RecursiveServiceDependencyException;
 use Wikimedia\UUID\GlobalIdGenerator;
 
 return [
@@ -245,13 +246,30 @@ return [
 	function ( MediaWikiServices $services ) : Wikimedia\Rdbms\LBFactory {
 		$mainConfig = $services->getMainConfig();
 
+		try {
+			$stash = $services->getMainObjectStash();
+		} catch ( RecursiveServiceDependencyException $e ) {
+			$stash = new EmptyBagOStuff(); // T141804: handle cases like CACHE_DB
+		}
+
+		if ( $stash instanceof EmptyBagOStuff ) {
+			// Use process cache if the main stash is disabled or there was recursion
+			$stash = new HashBagOStuff( [ 'maxKeys' => 100 ] );
+		}
+
+		try {
+			$wanCache = $services->getMainWANObjectCache();
+		} catch ( RecursiveServiceDependencyException $e ) {
+			$wanCache = WANObjectCache::newEmpty(); // T141804: handle cases like CACHE_DB
+		}
+
 		$lbConf = MWLBFactory::applyDefaultConfig(
 			$mainConfig->get( 'LBFactoryConf' ),
 			new ServiceOptions( MWLBFactory::APPLY_DEFAULT_CONFIG_OPTIONS, $mainConfig ),
 			$services->getConfiguredReadOnlyMode(),
 			$services->getLocalServerObjectCache(),
-			$services->getMainObjectStash(),
-			$services->getMainWANObjectCache()
+			$stash,
+			$wanCache
 		);
 
 		$class = MWLBFactory::getLBFactoryClass( $lbConf );
diff --git a/includes/db/MWLBFactory.php b/includes/db/MWLBFactory.php
index b5e70cdbaaa..75bc17a270c 100644
--- a/includes/db/MWLBFactory.php
+++ b/includes/db/MWLBFactory.php
@@ -157,7 +157,9 @@ abstract class MWLBFactory {
 			$options->get( 'DBprefix' )
 		);
 
-		$lbConf = self::injectObjectCaches( $lbConf, $srvCache, $mainStash, $wanCache );
+		$lbConf['srvCache'] = $srvCache;
+		$lbConf['memStash'] = $mainStash;
+		$lbConf['wanCache'] = $wanCache;
 
 		return $lbConf;
 	}
@@ -214,35 +216,6 @@ abstract class MWLBFactory {
 		return $server;
 	}
 
-	/**
-	 * @param array $lbConf
-	 * @param BagOStuff $sCache
-	 * @param BagOStuff $mStash
-	 * @param WANObjectCache $wCache
-	 * @return array
-	 */
-	private static function injectObjectCaches(
-		array $lbConf, BagOStuff $sCache, BagOStuff $mStash, WANObjectCache $wCache
-	) {
-		// Fallback if APC style caching is not an option
-		if ( $sCache instanceof EmptyBagOStuff ) {
-			$sCache = new HashBagOStuff( [ 'maxKeys' => 100 ] );
-		}
-
-		// Use APC/memcached style caching, but avoids loops with CACHE_DB (T141804)
-		if ( $sCache->getQoS( $sCache::ATTR_EMULATION ) > $sCache::QOS_EMULATION_SQL ) {
-			$lbConf['srvCache'] = $sCache;
-		}
-		if ( $mStash->getQoS( $mStash::ATTR_EMULATION ) > $mStash::QOS_EMULATION_SQL ) {
-			$lbConf['memStash'] = $mStash;
-		}
-		if ( $wCache->getQoS( $wCache::ATTR_EMULATION ) > $wCache::QOS_EMULATION_SQL ) {
-			$lbConf['wanCache'] = $wCache;
-		}
-
-		return $lbConf;
-	}
-
 	/**
 	 * @param array $servers
 	 * @param string $ldDB Local domain database name
diff --git a/includes/objectcache/ObjectCache.php b/includes/objectcache/ObjectCache.php
index 053e6c7cc0e..6226f91b1ef 100644
--- a/includes/objectcache/ObjectCache.php
+++ b/includes/objectcache/ObjectCache.php
@@ -175,6 +175,12 @@ class ObjectCache {
 						$server['dbDirectory'] = $conf->get( 'SQLiteDataDir' );
 					}
 				}
+			} elseif ( !isset( $params['localKeyLB'] ) ) {
+				$params['localKeyLB'] = [
+					'factory' => function () {
+						return MediaWikiServices::getInstance()->getDBLoadBalancer();
+					}
+				];
 			}
 		}
 
diff --git a/includes/objectcache/SqlBagOStuff.php b/includes/objectcache/SqlBagOStuff.php
index 0b61626fcc8..1455d0edeed 100644
--- a/includes/objectcache/SqlBagOStuff.php
+++ b/includes/objectcache/SqlBagOStuff.php
@@ -21,13 +21,14 @@
  * @ingroup Cache
  */
 
-use MediaWiki\MediaWikiServices;
 use Wikimedia\AtEase\AtEase;
+use Wikimedia\ObjectFactory;
 use Wikimedia\Rdbms\Database;
 use Wikimedia\Rdbms\DBConnectionError;
 use Wikimedia\Rdbms\DBError;
 use Wikimedia\Rdbms\DBQueryError;
 use Wikimedia\Rdbms\IDatabase;
+use Wikimedia\Rdbms\ILoadBalancer;
 use Wikimedia\Rdbms\IMaintainableDatabase;
 use Wikimedia\ScopedCallback;
 use Wikimedia\Timestamp\ConvertibleTimestamp;
@@ -39,11 +40,16 @@ use Wikimedia\WaitConditionLoop;
  * @ingroup Cache
  */
 class SqlBagOStuff extends MediumSpecificBagOStuff {
+	/** @var ILoadBalancer|null */
+	protected $localKeyLb;
+	/** @var ILoadBalancer|null */
+	protected $globalKeyLb;
+
 	/** @var array[] (server index => server config) */
-	protected $serverInfos;
+	protected $serverInfos = [];
 	/** @var string[] (server index => tag/host name) */
-	protected $serverTags;
-	/** @var int */
+	protected $serverTags = [];
+	/** @var int Number of database servers shards (e.g. horizontal/vertical partitions) */
 	protected $numServerShards;
 	/** @var int UNIX timestamp */
 	protected $lastGarbageCollect = 0;
@@ -58,11 +64,11 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	/** @var bool */
 	protected $replicaOnly = false;
 
-	/** @var array */
+	/** @var IMaintainableDatabase[] Map of (shard index => DB handle) */
 	protected $conns;
-	/** @var array UNIX timestamps */
+	/** @var float[] Map of (shard index => UNIX timestamps) */
 	protected $connFailureTimes = [];
-	/** @var array Exceptions */
+	/** @var Exception[] Map of (shard index => Exception) */
 	protected $connFailureErrors = [];
 
 	/** @var int */
@@ -77,42 +83,44 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	/** @var string */
 	private static $OP_DELETE = 'delete';
 
+	/** @var string */
+	private const SHARD_LOCAL = 'local';
+	/** @var string */
+	private const SHARD_GLOBAL = 'global';
+
 	/**
 	 * Constructor. Parameters are:
-	 *   - server:      A server info structure in the format required by each
-	 *                  element in $wgDBServers.
-	 *
-	 *   - servers:     An array of server info structures describing a set of database servers
-	 *                  to distribute keys to. If this is specified, the "server" option will be
-	 *                  ignored. If string keys are used, then they will be used for consistent
-	 *                  hashing *instead* of the host name (from the server config). This is useful
-	 *                  when a cluster is replicated to another site (with different host names)
-	 *                  but each server has a corresponding replica in the other cluster.
-	 *
-	 *   - purgePeriod: The average number of object cache writes in between
-	 *                  garbage collection operations, where expired entries
-	 *                  are removed from the database. Or in other words, the
-	 *                  reciprocal of the probability of purging on any given
-	 *                  write. If this is set to zero, purging will never be done.
-	 *
-	 *   - purgeLimit:  Maximum number of rows to purge at once.
-	 *
-	 *   - tableName:   The table name to use, default is "objectcache".
-	 *
-	 *   - shards:      The number of tables to use for data storage on each server.
-	 *                  If this is more than 1, table names will be formed in the style
-	 *                  objectcacheNNN where NNN is the shard index, between 0 and
-	 *                  shards-1. The number of digits will be the minimum number
-	 *                  required to hold the largest shard index. Data will be
-	 *                  distributed across all tables by key hash. This is for
-	 *                  MySQL bugs 61735 <https://bugs.mysql.com/bug.php?id=61735>
-	 *                  and 61736 <https://bugs.mysql.com/bug.php?id=61736>.
-	 *
-	 *   - replicaOnly: Whether to only use replica DBs and avoid triggering
-	 *                  garbage collection logic of expired items. This only
-	 *                  makes sense if the primary DB is used and only if get()
-	 *                  calls will be used. This is used by ReplicatedBagOStuff.
-	 *   - syncTimeout: Max seconds to wait for replica DBs to catch up for WRITE_SYNC.
+	 *   - server: Server config map for Database::factory() that describes the database
+	 *      to use for all key operations. This overrides "localKeyLB" and "globalKeyLB".
+	 *   - servers: Array of server config maps, each for Database::factory(), describing a set
+	 *      of database servers to distribute keys to. If this is specified, the "server" option
+	 *      will be ignored. If string keys are used, then they will be used for consistent
+	 *      hashing *instead* of the host name (from the server config). This is useful
+	 *      when a cluster is replicated to another site (with different host names)
+	 *      but each server has a corresponding replica in the other cluster.
+	 *   - localKeyLB: ObjectFactory::getObjectFromSpec array yeilding ILoadBalancer.
+	 *      This load balancer is used for local keys, e.g. those using makeKey().
+	 *      This is overriden by 'server'/'servers'.
+	 *   - globalKeyLB: ObjectFactory::getObjectFromSpec array yeilding ILoadBalancer.
+	 *      This load balancer is used for local keys, e.g. those using makeGlobalKey().
+	 *      This is overriden by 'server'/'servers'.
+	 *   - purgePeriod: The average number of object cache writes in between arbage collection
+	 *      operations, where expired entries are removed from the database. Or in other words,
+	 *      the reciprocal of the probability of purging on any given write. If this is set to
+	 *      zero, purging will never be done. [optional]
+	 *   - purgeLimit: Maximum number of rows to purge at once. [optional]
+	 *   - tableName: The table name to use, default is "objectcache". [optional]
+	 *   - shards: The number of tables to use for data storage on each server.
+	 *      If this is more than 1, table names will be formed in the style objectcacheNNN where
+	 *      NNN is the shard index, between 0 and shards-1. The number of digits will be the
+	 *      minimum number required to hold the largest shard index. Data will be distributed
+	 *      across all tables by key hash. This is for MySQL bugs 61735
+	 *      <https://bugs.mysql.com/bug.php?id=61735> and 61736
+	 *      <https://bugs.mysql.com/bug.php?id=61736>. [optional]
+	 *   - replicaOnly: Whether to only use replica DBs and avoid triggering garbage collection
+	 *      logic of expired items. This only makes sense if the primary DB is used and only if
+	 *      get() calls will be used. This is used by ReplicatedBagOStuff. [optional]
+	 *   - syncTimeout: Max seconds to wait for replica DBs to catch up for WRITE_SYNC. [optional]
 	 *
 	 * @param array $params
 	 */
@@ -120,29 +128,36 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		parent::__construct( $params );
 
 		$this->attrMap[self::ATTR_EMULATION] = self::QOS_EMULATION_SQL;
-		$this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_NONE;
 
-		if ( isset( $params['servers'] ) ) {
-			$this->serverInfos = [];
-			$this->serverTags = [];
-			$this->numServerShards = count( $params['servers'] );
+		if ( isset( $params['servers'] ) || isset( $params['server'] ) ) {
 			$index = 0;
-			foreach ( $params['servers'] as $tag => $info ) {
+			foreach ( ( $params['servers'] ?? [ $params['server'] ] ) as $tag => $info ) {
 				$this->serverInfos[$index] = $info;
-				if ( is_string( $tag ) ) {
-					$this->serverTags[$index] = $tag;
-				} else {
-					$this->serverTags[$index] = $info['host'] ?? "#$index";
-				}
+				$this->serverTags[$index] = is_string( $tag ) ? $tag : "#$index";
 				++$index;
 			}
-		} elseif ( isset( $params['server'] ) ) {
-			$this->serverInfos = [ $params['server'] ];
+			// Horizontal partitioning by key hash (if any)
 			$this->numServerShards = count( $this->serverInfos );
+			$this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_NONE;
 		} else {
-			// Default to using the main wiki's database servers
-			$this->serverInfos = [];
-			$this->numServerShards = 1;
+			if ( isset( $params['localKeyLB'] ) ) {
+				$this->localKeyLb = ( $params['localKeyLB'] instanceof ILoadBalancer )
+					? $params['localKeyLB']
+					: ObjectFactory::getObjectFromSpec( $params['localKeyLB'] );
+			}
+			if ( isset( $params['globalKeyLB'] ) ) {
+				$this->globalKeyLb = ( $params['globalKeyLB'] instanceof ILoadBalancer )
+					? $params['globalKeyLB']
+					: ObjectFactory::getObjectFromSpec( $params['globalKeyLB'] );
+			}
+			$this->localKeyLb = $this->localKeyLb ?: $this->globalKeyLb;
+			if ( !$this->localKeyLb ) {
+				throw new InvalidArgumentException(
+					"Config requires 'server', 'servers', or 'localKeyLB'/'globalKeyLB'"
+				);
+			}
+			// Verticle partitioning by global vs local keys (if any)
+			$this->numServerShards = ( $this->localKeyLb === $this->globalKeyLb ) ? 1 : 2;
 			$this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_BE;
 		}
 		if ( isset( $params['purgePeriod'] ) ) {
@@ -164,16 +179,13 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	/**
 	 * Get a connection to the specified database
 	 *
-	 * @param int $shardIndex
+	 * @param int|string $shardIndex Server index or self::SHARD_LOCAL/self::SHARD_GLOBAL
 	 * @return IMaintainableDatabase
-	 * @throws MWException
+	 * @throws DBConnectionError
+	 * @throws UnexpectedValueException
 	 */
 	private function getConnection( $shardIndex ) {
-		if ( $shardIndex >= $this->numServerShards ) {
-			throw new MWException( __METHOD__ . ": Invalid server index \"$shardIndex\"" );
-		}
-
-		# Don't keep timing out trying to connect for each call if the DB is down
+		// Don't keep timing out trying to connect if the server is down
 		if (
 			isset( $this->connFailureErrors[$shardIndex] ) &&
 			( $this->getCurrentTime() - $this->connFailureTimes[$shardIndex] ) < 60
@@ -181,75 +193,70 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 			throw $this->connFailureErrors[$shardIndex];
 		}
 
-		if ( $this->serverInfos ) {
-			if ( !isset( $this->conns[$shardIndex] ) ) {
-				// Use custom database defined by server connection info
-				$info = $this->serverInfos[$shardIndex];
-				$type = $info['type'] ?? 'mysql';
-				$host = $info['host'] ?? '[unknown]';
-				$this->logger->debug( __CLASS__ . ": connecting to $host" );
-				$conn = Database::factory( $type, $info );
-				$conn->clearFlag( DBO_TRX ); // auto-commit mode
-				$this->conns[$shardIndex] = $conn;
-				// Automatically create the objectcache table for sqlite as needed
-				if ( $conn->getType() === 'sqlite' ) {
-					$this->initSqliteDatabase( $conn );
-				}
+		if ( $shardIndex === self::SHARD_LOCAL ) {
+			$conn = $this->getConnectionViaLoadBalancer( $shardIndex );
+		} elseif ( $shardIndex === self::SHARD_GLOBAL ) {
+			$conn = $this->getConnectionViaLoadBalancer( $shardIndex );
+		} elseif ( is_int( $shardIndex ) ) {
+			if ( isset( $this->serverInfos[$shardIndex] ) ) {
+				$server = $this->serverInfos[$shardIndex];
+				$conn = $this->getConnectionFromServerInfo( $shardIndex, $server );
+			} else {
+				throw new UnexpectedValueException( "Invalid server index #$shardIndex" );
 			}
-			$conn = $this->conns[$shardIndex];
 		} else {
-			// Use the main LB database
-			$lb = MediaWikiServices::getInstance()->getDBLoadBalancer();
-			$index = $this->replicaOnly ? DB_REPLICA : DB_MASTER;
-			// If the RDBMS has row-level locking, use the autocommit connection to avoid
-			// contention and deadlocks. Do not do this if it only has DB-level locking since
-			// that would just cause deadlocks.
-			$attribs = $lb->getServerAttributes( $lb->getWriterIndex() );
-			$flags = $attribs[Database::ATTR_DB_LEVEL_LOCKING] ? 0 : $lb::CONN_TRX_AUTOCOMMIT;
-			$conn = $lb->getMaintenanceConnectionRef( $index, [], false, $flags );
+			throw new UnexpectedValueException( "Invalid server index '$shardIndex'" );
 		}
 
-		$this->logger->debug( sprintf( "Connection %s will be used for SqlBagOStuff", $conn ) );
-
 		return $conn;
 	}
 
 	/**
 	 * Get the server index and table name for a given key
 	 * @param string $key
-	 * @return array Server index and table name
+	 * @return array (server index or self::SHARD_LOCAL/self::SHARD_GLOBAL, table name)
 	 */
-	private function getTableByKey( $key ) {
+	private function getKeyLocation( $key ) {
+		if ( $this->serverTags ) {
+			// Striped array of database servers
+			if ( count( $this->serverTags ) == 1 ) {
+				$shardIndex = 0; // short-circuit
+			} else {
+				$sortedServers = $this->serverTags;
+				ArrayUtils::consistentHashSort( $sortedServers, $key );
+				reset( $sortedServers );
+				$shardIndex = key( $sortedServers );
+			}
+		} else {
+			// LoadBalancer based configuration
+			$shardIndex = ( strpos( $key, 'global:' ) === 0 && $this->globalKeyLb )
+				? self::SHARD_GLOBAL
+				: self::SHARD_LOCAL;
+		}
+
 		if ( $this->numTableShards > 1 ) {
 			$hash = hexdec( substr( md5( $key ), 0, 8 ) ) & 0x7fffffff;
 			$tableIndex = $hash % $this->numTableShards;
 		} else {
-			$tableIndex = 0;
-		}
-		if ( $this->numServerShards > 1 ) {
-			$sortedServers = $this->serverTags;
-			ArrayUtils::consistentHashSort( $sortedServers, $key );
-			reset( $sortedServers );
-			$shardIndex = key( $sortedServers );
-		} else {
-			$shardIndex = 0;
+			$tableIndex = null;
 		}
+
 		return [ $shardIndex, $this->getTableNameByShard( $tableIndex ) ];
 	}
 
 	/**
 	 * Get the table name for a given shard index
-	 * @param int $index
+	 * @param int|null $index
 	 * @return string
 	 */
 	private function getTableNameByShard( $index ) {
-		if ( $this->numTableShards > 1 ) {
+		if ( $index !== null && $this->numTableShards > 1 ) {
 			$decimals = strlen( $this->numTableShards - 1 );
-			return $this->tableName .
-				sprintf( "%0{$decimals}d", $index );
-		} else {
-			return $this->tableName;
+
+			return $this->tableName . sprintf( "%0{$decimals}d", $index );
 		}
+
+		return $this->tableName;
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
@@ -279,21 +286,22 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		return $values;
 	}
 
-	private function fetchBlobMulti( array $keys, $flags = 0 ) {
+	private function fetchBlobMulti( array $keys ) {
 		$values = []; // array of (key => value)
 
-		$keysByTable = [];
+		$keysByTableByShardIndex = [];
 		foreach ( $keys as $key ) {
-			list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
-			$keysByTable[$shardIndex][$tableName][] = $key;
+			list( $shardIndex, $tableName ) = $this->getKeyLocation( $key );
+			$keysByTableByShardIndex[$shardIndex][$tableName][] = $key;
 		}
 
 		$dataRows = [];
-		foreach ( $keysByTable as $shardIndex => $serverKeys ) {
+		foreach ( $keysByTableByShardIndex as $shardIndex => $serverKeys ) {
 			try {
 				$db = $this->getConnection( $shardIndex );
 				foreach ( $serverKeys as $tableName => $tableKeys ) {
-					$res = $db->select( $tableName,
+					$res = $db->select(
+						$tableName,
 						[ 'keyname', 'value', 'exptime' ],
 						[ 'keyname' => $tableKeys ],
 						__METHOD__,
@@ -351,10 +359,10 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	 * @return bool
 	 */
 	private function modifyMulti( array $data, $exptime, $flags, $op ) {
-		$keysByTable = [];
+		$keysByTableByShardIndex = [];
 		foreach ( $data as $key => $value ) {
-			list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
-			$keysByTable[$shardIndex][$tableName][] = $key;
+			list( $shardIndex, $tableName ) = $this->getKeyLocation( $key );
+			$keysByTableByShardIndex[$shardIndex][$tableName][] = $key;
 		}
 
 		$exptime = $this->getExpirationAsTimestamp( $exptime );
@@ -362,7 +370,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		$result = true;
 		/** @noinspection PhpUnusedLocalVariableInspection */
 		$silenceScope = $this->silenceTransactionProfiler();
-		foreach ( $keysByTable as $shardIndex => $serverKeys ) {
+		foreach ( $keysByTableByShardIndex as $shardIndex => $serverKeys ) {
 			$db = null; // in case of connection failure
 			try {
 				$db = $this->getConnection( $shardIndex );
@@ -376,7 +384,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 
 			foreach ( $serverKeys as $tableName => $tableKeys ) {
 				try {
-					$result = $this->updateTableKeys(
+					$result = $this->updateTable(
 						$op,
 						$db,
 						$tableName,
@@ -393,7 +401,9 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		}
 
 		if ( $this->fieldHasFlags( $flags, self::WRITE_SYNC ) ) {
-			$result = $this->waitForReplication() && $result;
+			foreach ( $keysByTableByShardIndex as $shardIndex => $unused ) {
+				$result = $this->waitForReplication( $shardIndex ) && $result;
+			}
 		}
 
 		return $result;
@@ -410,7 +420,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	 * @throws DBError
 	 * @throws InvalidArgumentException
 	 */
-	private function updateTableKeys( $op, $db, $table, $tableKeys, $data, $dbExpiry ) {
+	private function updateTable( $op, $db, $table, $tableKeys, $data, $dbExpiry ) {
 		$success = true;
 
 		if ( $op === self::$OP_ADD ) {
@@ -473,7 +483,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doCas( $casToken, $key, $value, $exptime = 0, $flags = 0 ) {
-		list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
+		list( $shardIndex, $tableName ) = $this->getKeyLocation( $key );
 		$exptime = $this->getExpirationAsTimestamp( $exptime );
 
 		/** @noinspection PhpUnusedLocalVariableInspection */
@@ -507,7 +517,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 
 		$success = (bool)$db->affectedRows();
 		if ( $this->fieldHasFlags( $flags, self::WRITE_SYNC ) ) {
-			$success = $this->waitForReplication() && $success;
+			$success = $this->waitForReplication( $shardIndex ) && $success;
 		}
 
 		return $success;
@@ -527,7 +537,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	public function incr( $key, $step = 1, $flags = 0 ) {
-		list( $shardIndex, $tableName ) = $this->getTableByKey( $key );
+		list( $shardIndex, $tableName ) = $this->getKeyLocation( $key );
 
 		$newCount = false;
 		/** @noinspection PhpUnusedLocalVariableInspection */
@@ -643,7 +653,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		/** @noinspection PhpUnusedLocalVariableInspection */
 		$silenceScope = $this->silenceTransactionProfiler();
 
-		$shardIndexes = range( 0, $this->numServerShards - 1 );
+		$shardIndexes = $this->getServerShardIndexes();
 		shuffle( $shardIndexes );
 
 		$ok = true;
@@ -688,15 +698,15 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		&$keysDeletedCount = 0
 	) {
 		$cutoffUnix = ConvertibleTimestamp::convert( TS_UNIX, $timestamp );
-		$shardIndexes = range( 0, $this->numTableShards - 1 );
-		shuffle( $shardIndexes );
+		$tableIndexes = range( 0, $this->numTableShards - 1 );
+		shuffle( $tableIndexes );
 
-		foreach ( $shardIndexes as $numShardsDone => $shardIndex ) {
+		foreach ( $tableIndexes as $numShardsDone => $tableIndex ) {
 			$continue = null; // last exptime
 			$lag = null; // purge lag
 			do {
 				$res = $db->select(
-					$this->getTableNameByShard( $shardIndex ),
+					$this->getTableNameByShard( $tableIndex ),
 					[ 'keyname', 'exptime' ],
 					array_merge(
 						[ 'exptime < ' . $db->addQuotes( $db->timestamp( $cutoffUnix ) ) ],
@@ -720,7 +730,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 					}
 
 					$db->delete(
-						$this->getTableNameByShard( $shardIndex ),
+						$this->getTableNameByShard( $tableIndex ),
 						[
 							'exptime < ' . $db->addQuotes( $db->timestamp( $cutoffUnix ) ),
 							'keyname' => $keys
@@ -735,7 +745,8 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 						$continueUnix = ConvertibleTimestamp::convert( TS_UNIX, $continue );
 						$remainingLag = $cutoffUnix - $continueUnix;
 						$processedLag = max( $lag - $remainingLag, 0 );
-						$doneRatio = ( $numShardsDone + $processedLag / $lag ) / $this->numTableShards;
+						$doneRatio =
+							( $numShardsDone + $processedLag / $lag ) / $this->numTableShards;
 					} else {
 						$doneRatio = 1;
 					}
@@ -756,7 +767,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	public function deleteAll() {
 		/** @noinspection PhpUnusedLocalVariableInspection */
 		$silenceScope = $this->silenceTransactionProfiler();
-		for ( $shardIndex = 0; $shardIndex < $this->numServerShards; $shardIndex++ ) {
+		foreach ( $this->getServerShardIndexes() as $shardIndex ) {
 			$db = null; // in case of connection failure
 			try {
 				$db = $this->getConnection( $shardIndex );
@@ -782,7 +793,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 			}
 		}
 
-		list( $shardIndex ) = $this->getTableByKey( $key );
+		list( $shardIndex ) = $this->getKeyLocation( $key );
 
 		$db = null; // in case of connection failure
 		try {
@@ -814,7 +825,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		if ( --$this->locks[$key]['depth'] <= 0 ) {
 			unset( $this->locks[$key] );
 
-			list( $shardIndex ) = $this->getTableByKey( $key );
+			list( $shardIndex ) = $this->getKeyLocation( $key );
 
 			$db = null; // in case of connection failure
 			try {
@@ -915,6 +926,56 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 		return unserialize( $serial );
 	}
 
+	/**
+	 * @param string $shardIndex self::SHARD_LOCAL/self::SHARD_GLOBAL
+	 * @return IMaintainableDatabase
+	 * @throws DBError
+	 */
+	private function getConnectionViaLoadBalancer( $shardIndex ) {
+		$lb = ( $shardIndex === self::SHARD_LOCAL ) ? $this->localKeyLb : $this->globalKeyLb;
+		if ( $lb->getServerAttributes( $lb->getWriterIndex() )[Database::ATTR_DB_LEVEL_LOCKING] ) {
+			// Use the main connection to avoid transaction deadlocks
+			$conn = $lb->getMaintenanceConnectionRef( DB_MASTER );
+		} else {
+			// If the RDBMs has row/table/page level locking, then use separate auto-commit
+			// connection to avoid needless contention and deadlocks.
+			$conn = $lb->getMaintenanceConnectionRef(
+				$this->replicaOnly ? DB_REPLICA : DB_MASTER, [],
+				false,
+				$lb::CONN_TRX_AUTOCOMMIT
+			);
+		}
+
+		return $conn;
+	}
+
+	/**
+	 * @param int $shardIndex
+	 * @param array $server Server config map
+	 * @return IMaintainableDatabase
+	 * @throws DBError
+	 */
+	private function getConnectionFromServerInfo( $shardIndex, array $server ) {
+		if ( !isset( $this->conns[$shardIndex] ) ) {
+			/** @var IMaintainableDatabase Auto-commit connection to the server */
+			$conn = Database::factory( $server['type'], array_merge(
+				$server,
+				[
+					'flags' => ( $server['flags'] ?? 0 ) & ~IDatabase::DBO_TRX,
+					'connLogger' => $this->logger,
+					'queryLogger' => $this->logger
+				]
+			) );
+			// Automatically create the objectcache table for sqlite as needed
+			if ( $conn->getType() === 'sqlite' && !$conn->tableExists( 'objectcache' ) ) {
+				$this->initSqliteDatabase( $conn );
+			}
+			$this->conns[$shardIndex] = $conn;
+		}
+
+		return $this->conns[$shardIndex];
+	}
+
 	/**
 	 * Handle a DBError which occurred during a read operation.
 	 *
@@ -1017,7 +1078,7 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	 * Create the shard tables on all databases (e.g. via eval.php/shell.php)
 	 */
 	public function createTables() {
-		for ( $shardIndex = 0; $shardIndex < $this->numServerShards; $shardIndex++ ) {
+		foreach ( $this->getServerShardIndexes() as $shardIndex ) {
 			$db = $this->getConnection( $shardIndex );
 			if ( in_array( $db->getType(), [ 'mysql', 'postgres' ], true ) ) {
 				for ( $i = 0; $i < $this->numTableShards; $i++ ) {
@@ -1030,25 +1091,44 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	/**
-	 * @return bool Whether the main DB is used, e.g. wfGetDB( DB_MASTER )
+	 * @return string[]|int[] List of server indexes or self::SHARD_LOCAL/self::SHARD_GLOBAL
 	 */
-	private function usesMainDB() {
-		return !$this->serverInfos;
+	private function getServerShardIndexes() {
+		if ( $this->serverTags ) {
+			// Striped array of database servers
+			$shardIndexes = range( 0, $this->numServerShards - 1 );
+		} else {
+			// LoadBalancer based configuration
+			$shardIndexes = [];
+			if ( $this->localKeyLb ) {
+				$shardIndexes[] = self::SHARD_LOCAL;
+			}
+			if ( $this->globalKeyLb ) {
+				$shardIndexes[] = self::SHARD_GLOBAL;
+			}
+		}
+
+		return $shardIndexes;
 	}
 
-	private function waitForReplication() {
-		if ( !$this->usesMainDB() ) {
-			// Custom DB server list; probably doesn't use replication
+	/**
+	 * Wait for replica DBs to catch up to the master DB
+	 *
+	 * @param int|string $shardIndex Server index or self::SHARD_LOCAL/self::SHARD_GLOBAL
+	 * @return bool Success
+	 */
+	private function waitForReplication( $shardIndex ) {
+		if ( is_int( $shardIndex ) ) {
+			return true; // striped only, no LoadBalancer
+		}
+
+		$lb = ( $shardIndex === self::SHARD_LOCAL ) ? $this->localKeyLb : $this->globalKeyLb;
+		if ( !$lb->hasStreamingReplicaServers() ) {
 			return true;
 		}
 
-		$lb = MediaWikiServices::getInstance()->getDBLoadBalancer();
-		if ( $lb->getServerCount() <= 1 ) {
-			return true; // no replica DBs
-		}
-
-		// Main LB is used; wait for any replica DBs to catch up
 		try {
+			// Wait for any replica DBs to catch up
 			$masterPos = $lb->getMasterPos();
 			if ( !$masterPos ) {
 				return true; // not applicable
@@ -1076,10 +1156,8 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	 * @return ScopedCallback|null
 	 */
 	private function silenceTransactionProfiler() {
-		if ( !$this->usesMainDB() ) {
-			// Custom DB is configured which either has no TransactionProfiler injected,
-			// or has one specific for cache use, which we shouldn't silence
-			return null;
+		if ( $this->serverInfos ) {
+			return null; // no TransactionProfiler injected anyway
 		}
 
 		$trxProfiler = Profiler::instance()->getTransactionProfiler();
diff --git a/tests/phpunit/includes/objectcache/SqlBagOStuffTest.php b/tests/phpunit/includes/objectcache/SqlBagOStuffTest.php
index 9ab1edc8be4..f7b748d28dd 100644
--- a/tests/phpunit/includes/objectcache/SqlBagOStuffTest.php
+++ b/tests/phpunit/includes/objectcache/SqlBagOStuffTest.php
@@ -32,7 +32,10 @@ class SqlBagOStuffTest extends MediaWikiIntegrationTestCase {
 		array $components,
 		string $expected
 	) {
-		$cache = new SqlBagOStuff( [ 'keyspace' => $keyspace ] );
+		$cache = new SqlBagOStuff( [
+			'keyspace' => $keyspace,
+			'servers' => []
+		] );
 		$this->assertSame( $expected, $cache->makeKey( $class, ...$components ) );
 	}
 }