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Natarajan, Vijaya

Publications and source records attributed to Natarajan, Vijaya.

Bulk Data Mover

Bulk Data Mover (BDM) is a high-level data transfer management tool. BDM handles the issue of large variance in file sizes and a big portion of small files by managing the file transfers with optimized transfer queue and concurrency management algorithms. For example, climate simulation data sets are characterized by large volume of files with extreme variance in file sizes. The BDN achieves high performance using a variety of techniques, including multi-threaded concurrent transfer connections, data channel caching, load balancing over multiple transfer servers, and storage i/o pre-fetching. Logging information from the BDM is collected and analyzed to study the effectiveness of the transfer management algorithms. The BDM can accept a request composed of multiple files or an entire directory. The request also contains the target site and directory where the replicated files will reside. If a directory is provided at the source, then the BDM will replicate the structure of the source directory at the target site. The BDM is capable of transferring multiple files concurrently as well as using parallel TCP streams. The optimal level of concurrency or parallel streams depends on the bandwidth capacity of the storage systems at both ends of the transfer as well as achievable bandwidth of the wide-area network. Hardware req.-PC, MAC, Multi-platform & Workstation; Software req.: Compile/version-Java 1.50_x or above; Type of files: source code, executable modules, installation instructions other, user guide; URL: http://sdm.lbl.gov/bdm/

Natarajan, Vijaya↗

DataMover-Lite

DataMover-Lite (DML) is a client program whose purpose is to automatically manage multi-file transfers to clients. It expects as its input a transfer-instruction file, and a local target directory where the files will be moved to. The input file contains the Logical File Names (LFNs) and the transfer URLs (TURLs) of files that need to be transferred. The TURLs can have various protocols depending on the server that manages the files, including gridftp, ftp, https, and srm. Given a multi-file request for a large number of files, the DML can issue concurrently a number of transfers in order to get the files. The number of transfers it can issue is set as a parameter and is usually less than 10. For example, if the multi-file is for 100 files, the DML may keep active only 5 transfers at any one time. When any of the 5 transfers completes it will initiate another transfer. It is not necessary for a single request to contain files whose TURLs have same protocol. If the request to the DML contains TURLs with various protocols, the DML will contact the various servers on different threads according to each TURL's protocol. The DMK take care if scheduling the transfers, monitoring their progress, releasing the files, and getting the authorization for each file to be transferred.

Natarajan, Vijaya↗