1. A method for cloud application redundancy comprising: acquiring first description information of a cloud application needing redundancy, wherein the first description information comprises information about a source network used at a production site by the cloud application needing redundancy and information about a source virtual machine used at the production site by the cloud application needing redundancy; generating second description information of the cloud application needing redundancy according to the first description information, wherein the second description information comprises information about a backup network used at a redundancy site by the cloud application needing redundancy and information about a backup virtual machine used at the redundancy site by the cloud application needing redundancy; and providing the second description information for the redundancy site, so that the redundancy site recovers the cloud application needing redundancy according to the second description information.