DB Linker

Database connection for master/slaves setup. This package provides drivers for DBAL. MasterSlavesDriver for auto switching between a master and slaves servers & RetryDriver for retrying query when some errors occurs.

Installation

run composer require ezweb/dblinker

Configuration

Master/Slaves connection

A MysqlMasterSlavesConnection wraps a mysql master connection & one or more mysql slaves connection. It execute "READ" queries on one of the slaves connections and "WRITE" queries on the master connection.

// master and slaves configuration$master = [
'driver' => 'mysqli',
'host' => $masterHostname,
'user' => $masterUsername,
'password' => $masterPassword,
'dbname' => $masterDb,
];
$slaves = [
[
'driver' => 'mysqli',
'host' => $slave1Hostname,
'user' => $slave1Username,
'password' => $slave1Password,
'dbname' => $slave1Db,
'weight' => $slave1Weight,
],
/** other slaves params **/
];
// connection configuration$params = [
'master' => $master,
'slaves' => $slaves,
'driverClass' => 'Ez\DbLinker\Driver\MysqlMasterSlavesDriver',
];
// Doctrine\DBAL\Configuration$connection = Doctrine\DBAL\DriverManager::getConnection($params);
var_dump($connection->fetchColumn('SELECT 1')); // slavevar_dump($connection->exec('INSERT INTO…')); // master

Retry connection

A MysqlRetryConnection wraps another mysql connection. Its goal is to transparently re-execute queries that provokes erros when it's possible to recover automatically.

// master and slaves configuration$params = [
'connectionParams' => [
/** mysql master/slaves, mysqli or pdo_mysql parameters **/
],
'driverClass' => 'Ez\DbLinker\Driver\MysqlRetryDriver',
'retryStrategy' => newEz\DbLinker\RetryStrategy\MysqlRetryStrategy,
]
// Doctrine\DBAL\Configuration$connection = Doctrine\DBAL\DriverManager::getConnection($params);
var_dump($connection->fetchColumn('SELECT 1')); // nothing specialvar_dump($connection->exec('SET SESSION WAIT_TIMEOUT = 1'));
sleep(2);
var_dump($connection->fetchColumn('SELECT 1')); // Connection will catch "MySQL has gone away", re-execute the query and return the results as if nothing happened

Usage

When using Doctrine\DBAL\DriverManager, the $connection it returns is an instance of Doctrine\DBAL\Connection, that wraps one or more *Connection. Take a look at its documentation for more information.

Note: You can nest a MysqlMasterSlavesConnection in a MysqlRetryConnection.

Tests

To run the test suite, you need Docker & Docker-Compose:

docker-compose run composer install
docker-compose run behat