Hybrid caching for cloud storage to support traditional application

To take better advantage of cloud storage, it is necessary to migrate traditional application to the cloud. In existing cloud storage platforms, files are divided into chunks and redundantly stored, but in such circumstances, random file write may lead to much delay. It is quite common to access file randomly in traditional applications, therefore the performance of traditional application will be reduced after being migrated to the cloud. In order to solve the problem, we propose the idea of adding client-side caching to augment the cloud storage. In this way, most data access operations are executed on client-side rather than in cloud. File write delay and the cloud load will be reduced consequently. With this point in mind, we designed and implemented LabCloud. Similar with other block/file cloud storages, the system is designed to be chunk layout, but a hybrid caching file system CFS is complemented on the client-side. CFS could be mounted on client-side file system, and is compatible with POSIX file system interface, thus traditional application deployed in local host can be configured and running in it without modification. In this paper we describe the design and implementation of LabCloud and evaluate the system by test suites and experiments. Results demonstrate that it meets the requirement of most traditional applications, and the performance of random file access in cloud is improved.