Merge pull request #15384 from craftcms/feature/db2

Share the mutex connection for element bulk ops

CHANGELOG-WIP.md

@@ -59,6 +59,7 @@
 - Added `craft\services\Entries::EVENT_AFTER_MOVE_TO_SECTION`.
 - Added `craft\services\Entries::EVENT_BEFORE_MOVE_TO_SECTION`.
 - Added `craft\services\Entries::moveEntryToSection()`.
+- Added `craft\base\ApplicationTrait::getDb2()`. ([#15384](https://github.com/craftcms/cms/pull/15384))
 - `craft\helpers\DateTimeHelper::toIso8601()` now has a `$setToUtc` argument.
 - `craft\helpers\UrlHelper::cpUrl()` now returns URLs based on the primary site’s base URL (if it has one), for console requests if the `baseCpUrl` config setting isn’t set, and the `@web` alias wasn’t explicitly defined. ([#15374](https://github.com/craftcms/cms/issues/15374))
 - Deprecated `craft\fields\BaseRelationField::$localizeRelations`.
@@ -85,3 +86,4 @@
 - Updated Yii to 2.0.51.
 - Updated yii2-debug to 2.1.25.
 - Updated svg-sanitizer to 0.19.
+- Fixed a bug where element operations could cause deadlocks when multiple authors were working simultaneously. ([#15329](https://github.com/craftcms/cms/issues/15329))

src/base/ApplicationTrait.php

@@ -144,6 +144,7 @@
  * @property-read Conditions $conditions The conditions service
  * @property-read Config $config The config service
  * @property-read Connection $db The database connection component
+ * @property-read Connection $db2 The database connection component used for mutex locks and element bulk op records
  * @property-read Dashboard $dashboard The dashboard service
  * @property-read Deprecator $deprecator The deprecator service
  * @property-read Drafts $drafts The drafts service
@@ -1104,6 +1105,20 @@ public function getDashboard(): Dashboard
         return $this->get('dashboard');
     }
 
+    /**
+     * Returns the database connection used for mutex locks and element bulk op records.
+     *
+     * This helps avoid erratic behavior when locks are used during transactions
+     * (see https://makandracards.com/makandra/17437-mysql-careful-when-using-database-locks-in-transactions).
+     *
+     * @return Connection
+     * @since 5.3.0
+     */
+    public function getDb2(): Connection
+    {
+        return $this->get('db2');
+    }
+
     /**
      * Returns the deprecator service.
      *

src/config/app.php

@@ -4,7 +4,7 @@
     'id' => 'CraftCMS',
     'name' => 'Craft CMS',
     'version' => '5.2.8',
-    'schemaVersion' => '5.0.0.21',
+    'schemaVersion' => '5.3.0.0',
     'minVersionRequired' => '4.5.0',
     'basePath' => dirname(__DIR__), // Defines the @app alias
     'runtimePath' => '@storage/runtime', // Defines the @runtime alias
@@ -219,6 +219,11 @@
             return Craft::createObject($config);
         },
 
+        'db2' => function() {
+            $config = craft\helpers\App::dbConfig();
+            return Craft::createObject($config);
+        },
+
         'formatter' => function() {
             return Craft::$app->getFormattingLocale()->getFormatter();
         },

src/helpers/App.php

@@ -1005,21 +1005,17 @@ public static function mailerConfig(?MailSettings $settings = null): array
      */
     public static function dbMutexConfig(): array
     {
-        // Use a dedicated connection, to avoid erratic behavior when locks are used during transactions
-        // https://makandracards.com/makandra/17437-mysql-careful-when-using-database-locks-in-transactions
-        $dbConfig = static::dbConfig();
-
         if (Craft::$app->getDb()->getIsMysql()) {
             return [
                 'class' => MysqlMutex::class,
-                'db' => $dbConfig,
+                'db' => 'db2',
                 'keyPrefix' => Craft::$app->id,
             ];
         }
 
         return [
             'class' => PgsqlMutex::class,
-            'db' => $dbConfig,
+            'db' => 'db2',
         ];
     }
 

src/migrations/Install.php

@@ -1021,7 +1021,6 @@ public function addForeignKeys(): void
         $this->addForeignKey(null, Table::ELEMENTS, ['draftId'], Table::DRAFTS, ['id'], 'CASCADE', null);
         $this->addForeignKey(null, Table::ELEMENTS, ['revisionId'], Table::REVISIONS, ['id'], 'CASCADE', null);
         $this->addForeignKey(null, Table::ELEMENTS, ['fieldLayoutId'], Table::FIELDLAYOUTS, ['id'], 'SET NULL', null);
-        $this->addForeignKey(null, Table::ELEMENTS_BULKOPS, ['elementId'], Table::ELEMENTS, ['id'], 'CASCADE', null);
         $this->addForeignKey(null, Table::ELEMENTS_OWNERS, ['elementId'], Table::ELEMENTS, ['id'], 'CASCADE', null);
         $this->addForeignKey(null, Table::ELEMENTS_OWNERS, ['ownerId'], Table::ELEMENTS, ['id'], 'CASCADE', null);
         $this->addForeignKey(null, Table::ELEMENTS_SITES, ['elementId'], Table::ELEMENTS, ['id'], 'CASCADE', null);

src/migrations/m240723_214330_drop_bulkop_fk.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace craft\migrations;
+
+use craft\db\Migration;
+use craft\db\Table;
+
+/**
+ * m240723_214330_drop_bulkop_fk migration.
+ */
+class m240723_214330_drop_bulkop_fk extends Migration
+{
+    /**
+     * @inheritdoc
+     */
+    public function safeUp(): bool
+    {
+        $this->dropForeignKeyIfExists(Table::ELEMENTS_BULKOPS, ['elementId']);
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function safeDown(): bool
+    {
+        echo "m240723_214330_drop_bulkop_fk cannot be reverted.\n";
+        return false;
+    }
+}

src/services/Elements.php

@@ -17,6 +17,7 @@
 use craft\base\NestedElementInterface;
 use craft\behaviors\DraftBehavior;
 use craft\behaviors\RevisionBehavior;
+use craft\db\Connection;
 use craft\db\Query;
 use craft\db\QueryAbortedException;
 use craft\db\Table;
@@ -77,6 +78,7 @@
 use yii\base\InvalidCallException;
 use yii\base\InvalidConfigException;
 use yii\caching\TagDependency;
+use yii\di\Instance;
 
 /**
  * The Elements service provides APIs for managing elements.
@@ -513,6 +515,15 @@ class Elements extends Component
      */
     private ?bool $_updateSearchIndex = null;
 
+    /**
+     * @inheritdoc
+     */
+    public function init()
+    {
+        parent::init();
+        $this->bulkOpDb = Instance::ensure($this->bulkOpDb, Connection::class);
+    }
+
     /**
      * Creates an element with a given config.
      *
@@ -548,6 +559,13 @@ public function createElementQuery(string $elementType): ElementQueryInterface
         return $elementType::find();
     }
 
+    /**
+     * @var Connection|array|string the DB connection object or the application component ID of the DB connection
+     * that should be used to store element bulk op records.
+     * @since 5.3.0
+     */
+    public Connection|array|string $bulkOpDb = 'db2';
+
     // Element caches
     // -------------------------------------------------------------------------
 
@@ -1135,7 +1153,7 @@ public function endBulkOp(string $key): void
             ]));
         }
 
-        Db::delete(Table::ELEMENTS_BULKOPS, ['key' => $key]);
+        Db::delete(Table::ELEMENTS_BULKOPS, ['key' => $key], db: $this->bulkOpDb);
     }
 
     /**
@@ -1157,7 +1175,7 @@ public function trackElementInBulkOps(ElementInterface $element): void
                 'elementId' => $element->id,
                 'key' => $key,
                 'timestamp' => $timestamp,
-            ]);
+            ], db: $this->bulkOpDb);
         }
     }