Merge pull request #553 from magento-performance/ACPT-1413

ACPT-1413: Child process mustn't close database and redis connections in parent

Author: andimov

lib/internal/Magento/Framework/App/ResourceConnection.php

@@ -128,7 +128,7 @@ public function closeConnection($resourceName = self::DEFAULT_CONNECTION)
             }
             $this->connections = [];
         } else {
-            $processConnectionName = $this->getProcessConnectionName($this->config->getConnectionName($resourceName));
+            $processConnectionName = $this->config->getConnectionName($resourceName);
             if (isset($this->connections[$processConnectionName])) {
                 if ($this->connections[$processConnectionName] !== null) {
                     $this->connections[$processConnectionName]->closeConnection();
@@ -147,9 +147,8 @@ public function closeConnection($resourceName = self::DEFAULT_CONNECTION)
      */
     public function getConnectionByName($connectionName)
     {
-        $processConnectionName = $this->getProcessConnectionName($connectionName);
-        if (isset($this->connections[$processConnectionName])) {
-            return $this->connections[$processConnectionName];
+        if (isset($this->connections[$connectionName])) {
+            return $this->connections[$connectionName];
         }
 
         $connectionConfig = $this->deploymentConfig->get(
@@ -162,21 +161,10 @@ public function getConnectionByName($connectionName)
             throw new \DomainException('Connection "' . $connectionName . '" is not defined');
         }
 
-        $this->connections[$processConnectionName] = $connection;
+        $this->connections[$connectionName] = $connection;
         return $connection;
     }
 
-    /**
-     * Get conneciton name for process.
-     *
-     * @param string $connectionName
-     * @return string
-     */
-    private function getProcessConnectionName($connectionName)
-    {
-        return $connectionName . '_process_' . getmypid();
-    }
-
     /**
      * Get resource table name, validated by db adapter.
      *

lib/internal/Magento/Framework/Cache/Frontend/Adapter/Zend.php

@@ -29,6 +29,13 @@ class Zend implements \Magento\Framework\Cache\FrontendInterface
      */
     private $pid;
 
+    /**
+     * We need to keep references to parent's frontends so that they don't get destroyed
+     *
+     * @var array
+     */
+    private $parentFrontends = [];
+
     /**
      * @param \Closure $frontendFactory
      */
@@ -147,6 +154,9 @@ private function getFrontEnd()
         if (getmypid() === $this->pid) {
             return $this->_frontend;
         }
+        // Note: We hide the parent process's _frontend so that the destructor won't get called on it.
+        // If the destructor were called, then the parent process's connection would be disconnected.
+        $this->parentFrontends[] = $this->_frontend;
         $frontendFactory = $this->frontendFactory;
         $this->_frontend = $frontendFactory();
         $this->pid = getmypid();

lib/internal/Magento/Framework/Config/Data/Scoped.php

@@ -22,27 +22,6 @@ class Scoped extends \Magento\Framework\Config\Data
      */
     protected $_configScope;
 
-    /**
-     * Configuration reader
-     *
-     * @var \Magento\Framework\Config\ReaderInterface
-     */
-    protected $_reader;
-
-    /**
-     * Configuration cache
-     *
-     * @var \Magento\Framework\Config\CacheInterface
-     */
-    protected $_cache;
-
-    /**
-     * Cache tag
-     *
-     * @var string
-     */
-    protected $_cacheId;
-
     /**
      * Scope priority loading scheme
      *

lib/internal/Magento/Framework/DB/Adapter/Pdo/Mysql.php

@@ -237,6 +237,20 @@ class Mysql extends \Zend_Db_Adapter_Pdo_Mysql implements AdapterInterface, Rese
      */
     private $schemaListener;
 
+    /**
+     * Process id that the connection is associated with
+     *
+     * @var int|null
+     */
+    private ?int $pid = null;
+
+    /**
+     * Parent process's database connection
+     *
+     * @var array
+     */
+    private $parentConnections = [];
+
     /**
      * Constructor
      *
@@ -255,6 +269,7 @@ public function __construct(
         array $config = [],
         SerializerInterface $serializer = null
     ) {
+        $this->pid = getmypid();
         $this->string = $string;
         $this->dateTime = $dateTime;
         $this->logger = $logger;
@@ -295,6 +310,7 @@ public function _resetState() : void
         $this->_isDdlCacheAllowed = true;
         $this->isMysql8Engine = null;
         $this->_queryHook = null;
+        $this->avoidReusingParentProcessConnection();
         $this->closeConnection();
     }
 
@@ -397,6 +413,23 @@ public function convertDateTime($datetime)
         return $this->formatDate($datetime, true);
     }
 
+    /**
+     * If the connection is associated to a different process id, then we need to not use it.
+     *
+     * @return void
+     */
+    private function avoidReusingParentProcessConnection()
+    {
+        if (getmypid() != $this->pid) {
+            // Note: we hide parent's connection into parentConnections so that the destructor isn't called on it.
+            // Because if destructor is called, it causes parent's connection to die
+            // We store in array, if parent is also hiding its parent's connection
+            $this->parentConnections[] = $this->_connection;
+            $this->_connection = null;
+            $this->pid = getmypid();
+        }
+    }
+
     /**
      * Creates a PDO object and connects to the database.
      *
@@ -409,6 +442,7 @@ public function convertDateTime($datetime)
      */
     protected function _connect()
     {
+        $this->avoidReusingParentProcessConnection();
         if ($this->_connection) {
             return;
         }

lib/internal/Magento/Framework/Locale/Resolver.php

@@ -180,7 +180,8 @@ public function revert()
      */
     public function _resetState(): void
     {
-        $this->locale = null;
-        $this->emulatedLocales = [];
+        while (!empty($this->emulatedLocales)) {
+            $this->revert();
+        }
     }
 }

lib/internal/Magento/Framework/Test/Unit/App/ResourceConnectionTest.php

@@ -125,7 +125,7 @@ public function testGetExistingConnectionByName()
             ResourceConnection::class,
             [
                 'deploymentConfig' => $this->deploymentConfigMock,
-                'connections' => ['default_process_' . getmypid() => 'existing_connection']
+                'connections' => ['default' => 'existing_connection']
             ]
         );
         $this->deploymentConfigMock->expects($this->never())->method('get');