For the Technical Preview of the Globus Toolkit 4.1.3 release we have designed and implemented a Data Replication Service (DRS) that provides a pull-based replication capability for Grid files. The DRS is a higher-level data management service that is built on top of two GT data management components: the Reliable File Transfer (RFT) Service and the Replica Location Service (RLS).

The function of the DRS is to ensure that a specified set of files exists on a storage site. The DRS begins by querying RLS to discover where the desired files exist in the Grid. After the files are located, the DRS creates a transfer request that is executed by RFT. After the transfers are completed, DRS registers the new replicas with RLS.

DRS is implemented as a Web service and complies with the Web Services Resource Framework (WSRF) specifications. When a DRS request is received, it creates a WS-Resource that is used to maintain state about each file being replicated, including which operations on the file have succeeded or failed.