Plasma and Fusion Research

Volume 16, 2405017 (2021)

Regular Articles

Demonstration of High-Speed Data Replication Relay Across Multiple Repository Sites Using a Global Loop Path
Hideya NAKANISHI, Kenjiro YAMANAKA1,2), Shinsuke TOKUNAGA3), Takahisa OZEKI3), Yuki HOMMA3), Hideo OHTSU3), Yasutomo ISHII3), Noriyoshi NAKAJIMA, Takashi YAMAMOTO, Masahiko EMOTO, Masaki OHSUNA, Tatsuki ITO, Setsuo IMAZU, Tomoyuki INOUE, Osamu NAKAMURA, Shunji ABE1,2) and Shigeo URUSHIDANI1,2)
National Institute for Fusion Science, NINS, Toki 509-5292, Japan
National Institute of Informatics, Tokyo 101-8430, Japan
The Graduate University for Advanced Studies (SOKENDAI), Hayama 240-0193, Japan
National Institutes for Quantum and Radiological Science and Technology, Rokkasho 039-3212, Japan
(Received 16 November 2020 / Accepted 25 December 2020 / Published 10 February 2021)


Technical verification has been progressing for high efficiency data replication between ITER and the Remote Experimentation Centre (REC) in Japan. Transferring a huge amount of data simultaneously to multiple destinations might cause excessive loads and network bandwidth on the sender so that daisy-chained relay transfer would be a considerable solution. This study demonstrates how efficiently the replication relay could be realized for the next-generation fusion experiments, such as ITER and JT-60SA. All the LHD data were consecutively sent to the REC through the global loop path (GLP: Toki - Gifu - Tokyo - Amsterdam - New York - Los Angeles - Tokyo - Aomori - Rokkasho) on SINET5 L2VPN, whose round-trip time is almost 400 ms. MMCFTP was used for the data transferring application. In both the Japan domestic path and the GLP cases, every transfer shows a very stable flattop speed as the preset 8 Gbps. However, longer gap times were needed in MMCFTP initial negotiation to establish numerous sessions. The performance optimized NVMe and iSCSI striped storages have shown higher throughputs than the ITER estimated initial data rate of 2 GB/s. Those knowledge enable the design optimization of not only the sender/receiver servers with their storages but also the intermediate relay server system.


ITER, Remote Experimentation Centre (REC), LHD, MMCFTP, L2VPN, SINET, global loop path, multi-site data repository, relay replication

DOI: 10.1585/pfr.16.2405017


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