(mongodb >=1.13.0)
The MongoDB\Driver\ServerDescription class is a value object that represents a server to which the driver is connected. Instances of this class are returned by MongoDB\Driver\Server::getServerDescription() and MongoDB\Driver\Monitoring\ServerChangedEvent methods.
MongoDB\Driver\ServerDescription::TYPE_UNKNOWNMongoDB\Driver\ServerDescription::TYPE_STANDALONEMongoDB\Driver\ServerDescription::TYPE_MONGOSMongoDB\Driver\ServerDescription::TYPE_POSSIBLE_PRIMARYMongoDB\Driver\ServerDescription::TYPE_RS_PRIMARYMongoDB\Driver\ServerDescription::TYPE_RS_SECONDARYMongoDB\Driver\ServerDescription::TYPE_RS_ARBITERMongoDB\Driver\ServerDescription::TYPE_RS_OTHERMongoDB\Driver\ServerDescription::TYPE_RS_GHOSTMongoDB\Driver\ServerDescription::TYPE_LOAD_BALANCER