From 44dd3cfa67f7b8f64482467c7bad01afb42e2b32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julius=20H=C3=A4rtl?= <jus@bitgrid.net>
Date: Wed, 29 Nov 2023 09:17:26 +0100
Subject: [PATCH] fix: Add reconnect check in case of timeouts on the db side
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Signed-off-by: Julius Härtl <jus@bitgrid.net>
---
 lib/private/DB/Connection.php | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/lib/private/DB/Connection.php b/lib/private/DB/Connection.php
index e3fda3e464fdb..ca7e9eeae2a75 100644
--- a/lib/private/DB/Connection.php
+++ b/lib/private/DB/Connection.php
@@ -41,6 +41,7 @@
 use Doctrine\DBAL\Connections\PrimaryReadReplicaConnection;
 use Doctrine\DBAL\Driver;
 use Doctrine\DBAL\Exception;
+use Doctrine\DBAL\Exception\ConnectionLost;
 use Doctrine\DBAL\Platforms\MySQLPlatform;
 use Doctrine\DBAL\Platforms\OraclePlatform;
 use Doctrine\DBAL\Platforms\SqlitePlatform;
@@ -78,6 +79,7 @@ class Connection extends PrimaryReadReplicaConnection {
 
 	/** @var DbDataCollector|null */
 	protected $dbDataCollector = null;
+	private int $lastConnectionCheck = 0;
 
 	/**
 	 * Initializes a new instance of the Connection class.
@@ -123,10 +125,13 @@ public function __construct(
 	public function connect($connectionName = null) {
 		try {
 			if ($this->_conn) {
+				$this->reconnectIfNeeded();
 				/** @psalm-suppress InternalMethod */
 				return parent::connect();
 			}
 
+			$this->lastConnectionCheck = time();
+
 			// Only trigger the event logger for the initial connect call
 			$eventLogger = \OC::$server->get(IEventLogger::class);
 			$eventLogger->start('connect:db', 'db connection opened');
@@ -618,4 +623,18 @@ protected function performConnect(?string $connectionName = null): bool {
 		}
 		return $result;
 	}
+
+	private function reconnectIfNeeded(): void {
+		if ($this->lastConnectionCheck + 30 >= time() || $this->isTransactionActive()) {
+			return;
+		}
+
+		try {
+			$this->_conn->query($this->getDriver()->getDatabasePlatform()->getDummySelectSQL());
+			$this->lastConnectionCheck = time();
+		} catch (ConnectionLost|\Exception $e) {
+			$this->logger->warning('Exception during connectivity check, closing and reconnecting', ['exception' => $e]);
+			$this->close();
+		}
+	}
 }