In long-running processes, allows checking the database connection by pinging it, thus avoiding exceptions. Additionally, it provides the flexibility to configure the frequency of the check to be performed in the case of long-running processes.

Author: alli83

src/Connection.php

@@ -42,6 +42,7 @@
 use function is_string;
 use function key;
 use function sprintf;
+use function time;
 
 /**
  * A database abstraction-level connection that implements features like transaction isolation levels,
@@ -99,6 +100,12 @@ class Connection implements ServerVersionProvider
 
     private SchemaManagerFactory $schemaManagerFactory;
 
+    private bool $isChecking = false;
+
+    private ?int $lastCheckedAt = null;
+
+    private ?int $heartbeat;
+
     /**
      * Initializes a new instance of the Connection class.
      *
@@ -115,6 +122,8 @@ public function __construct(
         protected Driver $driver,
         ?Configuration $config = null,
     ) {
+        $this->heartbeat = $params['check_connection_frequency'] ?? null;
+
         $this->_config    = $config ?? new Configuration();
         $this->params     = $params;
         $this->autoCommit = $this->_config->getAutoCommit();
@@ -210,7 +219,23 @@ public function createExpressionBuilder(): ExpressionBuilder
     protected function connect(): DriverConnection
     {
         if ($this->_conn !== null) {
-            return $this->_conn;
+            $isTimeToCheck = $this->lastCheckedAt === null || time() - $this->lastCheckedAt >= $this->heartbeat;
+            $noCheckNeeded = $this->heartbeat === null || $this->isChecking;
+
+            if ($noCheckNeeded || ! $isTimeToCheck) {
+                return $this->_conn;
+            }
+
+            $this->isChecking = true;
+
+            $isAvailable = $this->reconnectOnFailure();
+
+            $this->lastCheckedAt = time();
+            $this->isChecking    = false;
+
+            if ($isAvailable) {
+                return $this->_conn;
+            }
         }
 
         try {
@@ -1371,4 +1396,15 @@ private function handleDriverException(
 
         return $exception;
     }
+
+    private function reconnectOnFailure(): bool
+    {
+        try {
+            $this->executeQuery($this->getDatabasePlatform($this)->getDummySelectSQL());
+
+            return true;
+        } catch (ConnectionLost) {
+            return false;
+        }
+    }
 }

tests/Functional/Connection/ConnectionReactivatedTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\DBAL\Tests\Functional\Connection;
+
+use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
+use Doctrine\DBAL\Tests\FunctionalTestCase;
+
+use function sleep;
+
+class ConnectionReactivatedTest extends FunctionalTestCase
+{
+    public static function setUpBeforeClass(): void
+    {
+        self::markConnectionWithHeartBeat();
+    }
+
+    protected function setUp(): void
+    {
+        if ($this->connection->getDatabasePlatform() instanceof AbstractMySQLPlatform) {
+            return;
+        }
+
+        self::markTestSkipped('Currently only supported with MySQL');
+    }
+
+    public function testConnectionReactivated(): void
+    {
+        $this->connection->executeStatement('SET SESSION wait_timeout=1');
+
+        sleep(2);
+
+        $query = $this->connection->getDatabasePlatform()
+            ->getDummySelectSQL();
+
+        $this->connection->executeQuery($query);
+
+        self::assertEquals(1, $this->connection->fetchOne($query));
+    }
+}

tests/FunctionalTestCase.php

@@ -26,6 +26,8 @@ abstract class FunctionalTestCase extends TestCase
      */
     private bool $isConnectionReusable = true;
 
+    protected static bool $hasHeartBeat = false;
+
     /**
      * Mark shared connection not reusable for subsequent tests.
      *
@@ -37,11 +39,16 @@ protected function markConnectionNotReusable(): void
         $this->isConnectionReusable = false;
     }
 
+    protected static function markConnectionWithHeartBeat(): void
+    {
+        self::$hasHeartBeat = true;
+    }
+
     #[Before]
     final protected function connect(): void
     {
         if (self::$sharedConnection === null) {
-            self::$sharedConnection = TestUtil::getConnection();
+            self::$sharedConnection = TestUtil::getConnection(self::$hasHeartBeat);
         }
 
         $this->connection = self::$sharedConnection;

tests/TestUtil.php

@@ -62,10 +62,14 @@ class TestUtil
      *
      * @return Connection The database connection instance.
      */
-    public static function getConnection(): Connection
+    public static function getConnection($hasHeartBeat = false): Connection
     {
         $params = self::getConnectionParams();
 
+        if ($hasHeartBeat) {
+            $params['check_connection_frequency'] = 1;
+        }
+
         if (empty($params['memory']) && ! self::$initialized) {
             self::initializeDatabase();
             self::$initialized = true;