[GH-4052] Deprecate MasterSlaveConnection and rename to PrimaryReplicaConnection

UPGRADE.md

 # Upgrade to 2.11
 
+## Deprecated `MasterSlaveConnection` use `PrimaryReadReplicaConnection`
+
+The `Doctrine\DBAL\Connections\MasterSlaveConnection` class is renamed to `Doctrine\DBAL\Connections\PrimaryReadReplicaConnection`.
+In addition its configuration parameters `master`, `slaves` and `keepSlave` are renamed to `primary`, `replica` and `keepReplica`.
+
+Before:
+
+    $connection = DriverManager::getConnection(
+        'wrapperClass' => 'Doctrine\DBAL\Connections\MasterSlaveConnection',
+        'driver' => 'pdo_mysql',
+        'master' => array('user' => '', 'password' => '', 'host' => '', 'dbname' => ''),
+        'slaves' => array(
+            array('user' => 'replica1', 'password', 'host' => '', 'dbname' => ''),
+            array('user' => 'replica2', 'password', 'host' => '', 'dbname' => ''),
+        ),
+        'keepSlave' => true,
+    ));
+    $connection->connect('slave');
+    $connection->connect('master');
+    $connection->isConnectedToMaster();
+
+After:
+
+    $connection = DriverManager::getConnection(array(
+        'wrapperClass' => 'Doctrine\DBAL\Connections\PrimaryReadReplicaConnection',
+        'driver' => 'pdo_mysql',
+        'primary' => array('user' => '', 'password' => '', 'host' => '', 'dbname' => ''),
+        'replica' => array(
+            array('user' => 'replica1', 'password', 'host' => '', 'dbname' => ''),
+            array('user' => 'replica2', 'password', 'host' => '', 'dbname' => ''),
+        )
+        'keepReplica' => true,
+    ));
+    $connection->ensureConnectedToReplica();
+    $connection->ensureConnectedToPrimary();
+    $connection->isConnectedToPrimary();
+
 ## Deprecated `ArrayStatement` and `ResultCacheStatement` classes.
 
 The `ArrayStatement` and `ResultCacheStatement` classes are deprecated. In a future major release they will be renamed and marked internal as implementation details of the caching layer.

lib/Doctrine/DBAL/DriverManager.php

@@ -142,17 +142,29 @@ final class DriverManager
 
         $params = self::parseDatabaseUrl($params);
 
-        // URL support for MasterSlaveConnection
+        // @todo: deprecated, notice thrown by connection constructor
         if (isset($params['master'])) {
             $params['master'] = self::parseDatabaseUrl($params['master']);
         }
 
+        // @todo: deprecated, notice thrown by connection constructor
         if (isset($params['slaves'])) {
             foreach ($params['slaves'] as $key => $slaveParams) {
                 $params['slaves'][$key] = self::parseDatabaseUrl($slaveParams);
             }
         }
 
+        // URL support for PrimaryReplicaConnection
+        if (isset($params['primary'])) {
+            $params['primary'] = self::parseDatabaseUrl($params['primary']);
+        }
+
+        if (isset($params['replica'])) {
+            foreach ($params['replica'] as $key => $replicaParams) {
+                $params['replica'][$key] = self::parseDatabaseUrl($replicaParams);
+            }
+        }
+
         // URL support for PoolingShardConnection
         if (isset($params['global'])) {
             $params['global'] = self::parseDatabaseUrl($params['global']);

tests/Doctrine/Tests/DBAL/DriverManagerTest.php

@@ -3,7 +3,7 @@
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Connection;
-use Doctrine\DBAL\Connections\MasterSlaveConnection;
+use Doctrine\DBAL\Connections\PrimaryReadReplicaConnection;
 use Doctrine\DBAL\DBALException;
 use Doctrine\DBAL\Driver;
 use Doctrine\DBAL\Driver\DrizzlePDOMySql\Driver as DrizzlePDOMySqlDriver;
@@ -139,15 +139,15 @@ class DriverManagerTest extends DbalTestCase
         self::assertInstanceOf(PDOMySQLDriver::class, $conn->getDriver());
     }
 
-    public function testDatabaseUrlMasterSlave(): void
+    public function testDatabaseUrlPrimaryReplica(): void
     {
         $options = [
             'driver' => 'pdo_mysql',
-            'master' => ['url' => 'mysql://foo:bar@localhost:11211/baz'],
-            'slaves' => [
-                'slave1' => ['url' => 'mysql://foo:bar@localhost:11211/baz_slave'],
+            'primary' => ['url' => 'mysql://foo:bar@localhost:11211/baz'],
+            'replica' => [
+                'replica1' => ['url' => 'mysql://foo:bar@localhost:11211/baz_replica'],
             ],
-            'wrapperClass' => MasterSlaveConnection::class,
+            'wrapperClass' => PrimaryReadReplicaConnection::class,
         ];
 
         $conn = DriverManager::getConnection($options);
@@ -163,12 +163,12 @@ class DriverManagerTest extends DbalTestCase
         ];
 
         foreach ($expected as $key => $value) {
-            self::assertEquals($value, $params['master'][$key]);
-            self::assertEquals($value, $params['slaves']['slave1'][$key]);
+            self::assertEquals($value, $params['primary'][$key]);
+            self::assertEquals($value, $params['replica']['replica1'][$key]);
         }
 
-        self::assertEquals('baz', $params['master']['dbname']);
-        self::assertEquals('baz_slave', $params['slaves']['slave1']['dbname']);
+        self::assertEquals('baz', $params['primary']['dbname']);
+        self::assertEquals('baz_replica', $params['replica']['replica1']['dbname']);
     }
 
     public function testDatabaseUrlShard(): void

tests/Doctrine/Tests/DBAL/Functional/PrimaryReadReplicaConnectionTest.php

+<?php
+
+namespace Doctrine\Tests\DBAL\Functional;
+
+use Doctrine\DBAL\Connections\PrimaryReadReplicaConnection;
+use Doctrine\DBAL\Driver\Statement;
+use Doctrine\DBAL\DriverManager;
+use Doctrine\DBAL\Schema\Table;
+use Doctrine\Tests\DbalFunctionalTestCase;
+use Throwable;
+
+use function array_change_key_case;
+use function sprintf;
+use function strlen;
+use function strtolower;
+use function substr;
+
+use const CASE_LOWER;
+
+/**
+ * @group DBAL-20
+ */
+class PrimaryReadReplicaConnectionTest extends DbalFunctionalTestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $platformName = $this->connection->getDatabasePlatform()->getName();
+
+        // This is a MySQL specific test, skip other vendors.
+        if ($platformName !== 'mysql') {
+            $this->markTestSkipped(sprintf('Test does not work on %s.', $platformName));
+        }
+
+        try {
+            $table = new Table('primary_replica_table');
+            $table->addColumn('test_int', 'integer');
+            $table->setPrimaryKey(['test_int']);
+
+            $sm = $this->connection->getSchemaManager();
+            $sm->createTable($table);
+        } catch (Throwable $e) {
+        }
+
+        $this->connection->executeUpdate('DELETE FROM primary_replica_table');
+        $this->connection->insert('primary_replica_table', ['test_int' => 1]);
+    }
+
+    private function createPrimaryReadReplicaConnection(bool $keepReplica = false): PrimaryReadReplicaConnection
+    {
+        return DriverManager::getConnection($this->createPrimaryReadReplicaConnectionParams($keepReplica));
+    }
+
+    /**
+     * @return mixed[]
+     */
+    private function createPrimaryReadReplicaConnectionParams(bool $keepReplica = false): array
+    {
+        $params                 = $this->connection->getParams();
+        $params['primary']      = $params;
+        $params['replica']      = [$params, $params];
+        $params['keepReplica']  = $keepReplica;
+        $params['wrapperClass'] = PrimaryReadReplicaConnection::class;
+
+        return $params;
+    }
+
+    public function testInheritCharsetFromPrimary(): void
+    {
+        $charsets = [
+            'utf8',
+            'latin1',
+        ];
+
+        foreach ($charsets as $charset) {
+            $params                       = $this->createPrimaryReadReplicaConnectionParams();
+            $params['primary']['charset'] = $charset;
+
+            foreach ($params['replica'] as $index => $replicaParams) {
+                if (! isset($replicaParams['charset'])) {
+                    continue;
+                }
+
+                unset($params['replica'][$index]['charset']);
+            }
+
+            $conn = DriverManager::getConnection($params);
+            self::assertInstanceOf(PrimaryReadReplicaConnection::class, $conn);
+            $conn->ensureConnectedToReplica();
+
+            self::assertFalse($conn->isConnectedToPrimary());
+
+            $clientCharset = $conn->fetchColumn('select @@character_set_client as c');
+
+            self::assertSame(
+                $charset,
+                substr(strtolower($clientCharset), 0, strlen($charset))
+            );
+        }
+    }
+
+    public function testPrimaryOnConnect(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection();
+
+        self::assertFalse($conn->isConnectedToPrimary());
+        $conn->ensureConnectedToReplica();
+        self::assertFalse($conn->isConnectedToPrimary());
+        $conn->ensureConnectedToPrimary();
+        self::assertTrue($conn->isConnectedToPrimary());
+    }
+
+    public function testNoPrimaryrOnExecuteQuery(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection();
+
+        $sql     = 'SELECT count(*) as num FROM primary_replica_table';
+        $data    = $conn->fetchAll($sql);
+        $data[0] = array_change_key_case($data[0], CASE_LOWER);
+
+        self::assertEquals(1, $data[0]['num']);
+        self::assertFalse($conn->isConnectedToPrimary());
+    }
+
+    public function testPrimaryOnWriteOperation(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection();
+        $conn->insert('primary_replica_table', ['test_int' => 30]);
+
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $sql     = 'SELECT count(*) as num FROM primary_replica_table';
+        $data    = $conn->fetchAll($sql);
+        $data[0] = array_change_key_case($data[0], CASE_LOWER);
+
+        self::assertEquals(2, $data[0]['num']);
+        self::assertTrue($conn->isConnectedToPrimary());
+    }
+
+    /**
+     * @group DBAL-335
+     */
+    public function testKeepReplicaBeginTransactionStaysOnPrimary(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection($keepReplica = true);
+        $conn->ensureConnectedToReplica();
+
+        $conn->beginTransaction();
+        $conn->insert('primary_replica_table', ['test_int' => 30]);
+        $conn->commit();
+
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $conn->connect();
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $conn->ensureConnectedToReplica();
+        self::assertFalse($conn->isConnectedToPrimary());
+    }
+
+    /**
+     * @group DBAL-335
+     */
+    public function testKeepReplicaInsertStaysOnPrimary(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection($keepReplica = true);
+        $conn->ensureConnectedToReplica();
+
+        $conn->insert('primary_replica_table', ['test_int' => 30]);
+
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $conn->connect();
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $conn->ensureConnectedToReplica();
+        self::assertFalse($conn->isConnectedToPrimary());
+    }
+
+    public function testPrimaryReadReplicaConnectionCloseAndReconnect(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection();
+        $conn->ensureConnectedToPrimary();
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $conn->close();
+        self::assertFalse($conn->isConnectedToPrimary());
+
+        $conn->ensureConnectedToPrimary();
+        self::assertTrue($conn->isConnectedToPrimary());
+    }
+
+    public function testQueryOnPrimary(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection();
+
+        $query = 'SELECT count(*) as num FROM primary_replica_table';
+
+        $statement = $conn->query($query);
+
+        self::assertInstanceOf(Statement::class, $statement);
+
+        //Query must be executed only on Primary
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $data = $statement->fetchAll();
+
+        //Default fetchmode is FetchMode::ASSOCIATIVE
+        self::assertArrayHasKey(0, $data);
+        self::assertArrayHasKey('num', $data[0]);
+
+        //Could be set in other fetchmodes
+        self::assertArrayNotHasKey(0, $data[0]);
+        self::assertEquals(1, $data[0]['num']);
+    }
+
+    public function testQueryOnReplica(): void
+    {
+        $conn = $this->createPrimaryReadReplicaConnection();
+        $conn->ensureConnectedToReplica();
+
+        $query = 'SELECT count(*) as num FROM primary_replica_table';
+
+        $statement = $conn->query($query);
+
+        self::assertInstanceOf(Statement::class, $statement);
+
+        //Query must be executed only on Primary, even when we connect to the replica
+        self::assertTrue($conn->isConnectedToPrimary());
+
+        $data = $statement->fetchAll();
+
+        //Default fetchmode is FetchMode::ASSOCIATIVE
+        self::assertArrayHasKey(0, $data);
+        self::assertArrayHasKey('num', $data[0]);
+
+        //Could be set in other fetchmodes
+        self::assertArrayNotHasKey(0, $data[0]);
+
+        self::assertEquals(1, $data[0]['num']);
+    }
+}