Manager::getDatabaseConnection

public function getDatabaseConnection()
{
	$pool = BitrixMainApplication::getInstance()->getConnectionPool();
	$connectionName = $this->connectionName ?: $pool::DEFAULT_CONNECTION_NAME;

	$conn = $pool->getConnection($connectionName);
	if (!$conn)
	{
		$conn = $pool->getConnection();
		$connectionName = $pool::DEFAULT_CONNECTION_NAME;
	}

	if (!is_a($conn, 'BitrixBIConnectorDBMysqliConnection'))
	{
		if (is_a($conn, 'BitrixMainDBMysqlCommonConnection'))
		{
			$pool->cloneConnection($connectionName , $connectionName . '~', [
				'className' => 'BitrixBIConnectorDBMysqliConnection',
			]);
			$conn = $pool->getConnection($connectionName . '~');
		}
		else
		{
			throw new BitrixMainConfigConfigurationException(sprintf(
				"Class '%s' for '%s' connection is not supported", get_class($conn), $this->connectionName
			));
		}
	}

	return $conn;
}