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/Configuration.php

@@ -36,6 +36,8 @@ class Configuration
 
     private ?SchemaManagerFactory $schemaManagerFactory = null;
 
+    private ?int $checkConnectionTiming = null;
+
     public function __construct()
     {
         $this->schemaAssetsFilter = static function (): bool {
@@ -153,4 +155,14 @@ public function setDisableTypeComments(bool $disableTypeComments): self
 
         return $this;
     }
+
+    public function setCheckConnectionTiming(int $timing): void
+    {
+        $this->checkConnectionTiming = $timing;
+    }
+
+    public function getCheckConnectionTiming(): ?int
+    {
+        return $this->checkConnectionTiming;
+    }
 }

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 = 0;
+
+    private ?int $heartbeat;
+
     /**
      * Initializes a new instance of the Connection class.
      *
@@ -119,6 +126,8 @@ public function __construct(
         $this->params     = $params;
         $this->autoCommit = $this->_config->getAutoCommit();
 
+        $this->heartbeat = $this->_config->getCheckConnectionTiming();
+
         $this->schemaManagerFactory = $this->_config->getSchemaManagerFactory()
             ?? new DefaultSchemaManagerFactory();
     }
@@ -210,7 +219,23 @@ public function createExpressionBuilder(): ExpressionBuilder
     protected function connect(): DriverConnection
     {
         if ($this->_conn !== null) {
-            return $this->_conn;
+            $isTimeToCheck =  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

@@ -62,7 +62,7 @@ class TestUtil
      *
      * @return Connection The database connection instance.
      */
-    public static function getConnection(): Connection
+    public static function getConnection($hasHeartBeat = false): Connection
     {
         $params = self::getConnectionParams();
 
@@ -75,7 +75,7 @@ public static function getConnection(): Connection
 
         return DriverManager::getConnection(
             $params,
-            self::createConfiguration($params['driver']),
+            self::createConfiguration($params['driver'], $hasHeartBeat),
         );
     }
 
@@ -153,7 +153,7 @@ private static function initializeDatabase(): void
         $privConn->close();
     }
 
-    private static function createConfiguration(string $driver): Configuration
+    private static function createConfiguration(string $driver, $hasHearBeat): Configuration
     {
         $configuration = new Configuration();
 
@@ -170,6 +170,10 @@ private static function createConfiguration(string $driver): Configuration
 
         $configuration->setSchemaManagerFactory(new DefaultSchemaManagerFactory());
 
+        if ($hasHearBeat) {
+            $configuration->setCheckConnectionTiming(1);
+        }
+
         return $configuration;
     }