1 files changed, 36 insertions, 0 deletions
diff --git a/lib/private/DB/SetTransactionIsolationLevel.php b/lib/private/DB/SetTransactionIsolationLevel.php
new file mode 100644
index 00000000000..cd18c4255e3
--- /dev/null
+++ b/lib/private/DB/SetTransactionIsolationLevel.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2019 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\DB;
+
+use Doctrine\Common\EventSubscriber;
+use Doctrine\DBAL\Connections\PrimaryReadReplicaConnection;
+use Doctrine\DBAL\Event\ConnectionEventArgs;
+use Doctrine\DBAL\Events;
+use Doctrine\DBAL\Platforms\MySQLPlatform;
+use Doctrine\DBAL\TransactionIsolationLevel;
+
+class SetTransactionIsolationLevel implements EventSubscriber {
+	/**
+	 * @param ConnectionEventArgs $args
+	 * @return void
+	 */
+	public function postConnect(ConnectionEventArgs $args) {
+		$connection = $args->getConnection();
+		if ($connection instanceof PrimaryReadReplicaConnection && $connection->isConnectedToPrimary()) {
+			$connection->setTransactionIsolation(TransactionIsolationLevel::READ_COMMITTED);
+			if ($connection->getDatabasePlatform() instanceof MySQLPlatform) {
+				$connection->executeStatement('SET SESSION AUTOCOMMIT=1');
+			}
+		}
+	}
+
+	public function getSubscribedEvents() {
+		return [Events::postConnect];
+	}
+}