/**
* Checks and disables the replica database server if appropriate.
*
* @param \Symfony\Component\HttpKernel\Event\GetResponseEvent $event
* The Event to process.
*/
public function checkReplicaServer(GetResponseEvent $event)
{
// Ignore replica database servers for this request.
//
// In Drupal's distributed database structure, new data is written to the
// master and then propagated to the replica servers. This means there is a
// lag between when data is written to the master and when it is available
// on the replica. At these times, we will want to avoid using a replica server
// temporarily. For example, if a user posts a new node then we want to
// disable the replica server for that user temporarily to allow the replica
// server to catch up.
// That way, that user will see their changes immediately while for other
// users we still get the benefits of having a replica server, just with
// slightly stale data. Code that wants to disable the replica server should
// use the db_set_ignore_replica() function to set
// $_SESSION['ignore_replica_server'] to the timestamp after which the replica
// can be re-enabled.
if (isset($_SESSION['ignore_replica_server'])) {
if ($_SESSION['ignore_replica_server'] >= REQUEST_TIME) {
Database::ignoreTarget('default', 'replica');
} else {
unset($_SESSION['ignore_replica_server']);
}
}
}
/**
* Tests that connections return appropriate connection objects.
*/
function testConnectionRoutingOverride()
{
// Clone the primary credentials to a replica connection.
// Note this will result in two independent connection objects that happen
// to point to the same place.
$connection_info = Database::getConnectionInfo('default');
Database::addConnectionInfo('default', 'replica', $connection_info['default']);
Database::ignoreTarget('default', 'replica');
$db1 = Database::getConnection('default', 'default');
$db2 = Database::getConnection('replica', 'default');
$this->assertIdentical($db1, $db2, 'Both targets refer to the same connection.');
}
public static function ignoreTarget($key, $target)
{
BaseDatabase::ignoreTarget($key, $target);
}
