An efficient and transparent transaction management based on the data workflow of HVEM DataGrid

This paper proposes an efficient and transparent transaction management on HVEM DataGrid. HVEM DataGrid has its data workflow which defines the precedence of the data to be saved. The precedence drives many states in a transaction for data management on HVEM DataGrid. We divide the transaction into several sub-transactions according to the states and classify the sub-transactions. Through the transaction hierarchy and parallelism, large image data can be uploaded to HVEM DataGrid efficiently and safely. The transaction management guarantees effective garbage collection as well. The garbage collection is important in HVEM DataGrid because it allows incomplete data insertion and update; it is not easy to decide whether the experimental results and their metadata are stored completely or not. Also, as shared storage system, HVEM DataGrid is composed of heterogeneous storages such as DBs and file storages. But, the transaction to save data to the datagrid requires to access those storages at the same time. And, the access should be transparent to users. The transaction hierarchy can solve the simultaneous access and satisfy these requirements. We will show the proposed scheme to be sound through analysis and to be effective by performance evaluation and overhead estimation. This paper shows that HVEM DataGrid can be a good model of e-Science datagrid through the efficient and transparent transaction scheme across many heterogeneous storages.