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A Study on the Performance Monitoring and Optimization of a High Speed Network for the Transfer of Massive VLBI Data

대용량 VLBI 데이터 전송을 위한 초고속 네트워크 성능 모니터링 및 최적화 연구

  • 송민규 (한국천문연구원 전파천문본부) ;
  • 강용우 (한국천문연구원 전파천문본부) ;
  • 김효령 (한국천문연구원 전파천문본부)
  • Received : 2019.10.22
  • Accepted : 2019.12.15
  • Published : 2019.12.31

Abstract

In VLBI(Very Long Baseline Interferometry), the observed data created in many observatories which are far away from each other should be collected in correlation center for data analysis. Traditionally, observed data is moved by transportation such as car or airplane. But it is replaced with data transfer over the network rapidly as the advancement of information technology, and therefore, international cooperative research is also now more widely expanding. e-KVN(electronic Korean VLBI Network) has been upgraded two times so the network interface of KVN has been evolved to the highest specification of 100GbE. During this time period, the portion of network usage for VLBI observations and experiments in KVN has been increased exponentially. In this paper, we describe KVN VLBI system and network technology for the performance upgrade and advanced status monitoring between three radio astronomy observatories and Daejeon correlation center with KREONET(Korea Research Environment Open NETwork). Furthermore, future plan of e-KVN for the implementation of wide band VLBI observation will be also briefly discussed.

VLBI에서 서로 멀리 떨어진 각 관측소에서 생성된 관측 데이터는 데이터 처리 및 분석을 위해 상관센터에 수집되어야 한다. 전통적으로 관측 데이터는 배나 비행기 등의 교통 수단을 통해 전달되었다. 하지만 IT 기술의 급격한 발전 속에 네트워크를 이용한 데이터 전송으로 빠르게 대체되고 있고 이를 통해 국제 공동 협업 연구가 더욱 활발해지고 있다. 이러한 기술 간 융합을 통한 연구 환경의 변화를 고려하여 2010년 9월 KVN 각 관측소와 상관센터를 초고속 네트워크로 연결하는 e-KVN이 구축되었고 두번의 업그레이드 과정을 통해 최대 100GbE에 달하는 인터페이스를 갖추게 되었다. 이후 KVN의 VLBI 관측 수행과 데이터 처리에 있어서 네트워크 활용 비중은 기하급수적으로 증가하고 있다. 본 논문에서는 KVN VLBI 시스템의 구성에 대해 살펴보고 세 관측소와 상관센터를 KREONET으로 연결하는 e-KVN의 성능 최적화 기법 및 개선된 모니터링 방안에 대해 기술하기로 한다. 나아가 광대역 관측 구현을 위한 e-KVN의 향후 계획에 대해 조망해보고자 한다.

Keywords

References

  1. A. Szomoru, A. Biggs, M. Garrett, H. Langevelde, F. Olnon, Z. Paragi, S. Parsley, S. Pogrebenko, and C. Reynolds, "From truck to optical fibre: the coming-of-age of eVLBI," Proc. of the 7th European VLBI Network Symp. Toledo, Spain, Oct. 2004. pp. 1-5.
  2. A. Whitney, M. Kettenis, C. Phillips, and M. Sekido, "VLBI data interchange format (VDIF)," 2010.
  3. M. Song, Y. Kang, and H. Kim, "Performance Evaluation of Big Stream based High Speed Data Storage," J. of the Korea Institute of Electronic Communication Sciences, vol. 12, no. 5, Oct. 2017, pp. 817-828. https://doi.org/10.13067/JKIECS.2017.12.5.817
  4. A. Thompson, J. Moran, and G. Swenson, Interferometry and Synthesis in Radio Astronomy. Weinheim: WILEY-VCH Verlag GmbH & Co. KGaA, 2004, pp. 257-264.
  5. M. Song, H. Kim, D. Byun, T. Jung, Y. Kang, H. Kim, J. Kim, S. Wi, S. Lee, D. Roh, S. Oh, and J. Yeom, The Design and Implementation of e-KVN Network for the Data Processing in Wideband VLBI Observation. Daejoen: Korea Astronomy and Space Science Institute, 2019, pp. 18-32.
  6. S. Han, J. Lee, J. Kang, C. Oh, D. Byun, D. Je, M. Chung, S. Wi, M. Song, Y. Kang, S. Lee, S. Kim, T. Sasao, P. Goldsmith, and R. Wylde, "Korean VLBI network receiver optics for simultaneous multifrequency observation: Evaluation.," Publications of the Astronomical Society of the Pacific, vol. 125, no. 927, May 2013. pp. 539-547. https://doi.org/10.1086/671125
  7. S. Oh, D. Roh, K. Wajima, N. Kawaguchi, D. Byun, J. Yeom, and K. Ozeki, "Design and Development of a High-Speed Data-Acquisition System for the Korean VLBI Network," Publications of the Astronomical Society of Japan, vol. 63, no. 6, Dec. 2011, pp. 1229-1242. https://doi.org/10.1093/pasj/63.6.1229
  8. M. Song, Y. Kang, and H. Kim, "The Study on the Design and Optimization of Storage for the Recording of High Speed Astronomical Data," J. of the Korea Institute of Electronic Communication Sciences, vol. 12, no. 1, Feb. 2017, pp. 75-84. https://doi.org/10.13067/JKIECS.2017.12.1.75
  9. B. Cho, "Korea Science Bigdata Super-Highway KREONET/KREONet2," The 10th Asian Forum for Accelerators and Detectors, New Delhi, India, Feb. 2019.
  10. M. Lee and K. Yoo, "Implementation of a Platform for the Big Scientific Data Transfers," J. of the Korea Institute of Electronic Communication Sciences, vol. 13, no. 4, Aug. 2018, pp. 881-886. https://doi.org/10.13067/JKIECS.2018.13.4.881
  11. iperf3 - iperf3 3.7 documentation - ESnet Software, https://software.es.net/iperf/
  12. T. Lakshman and U. Madhow, "The performance of TCP/IP for networks with high bandwidth-delay products and random loss," IEEE/ACM Trans. on networking, vol. 5, no. 3, June 1997. pp. 336-350. https://doi.org/10.1109/90.611099
  13. K. Fall and R. Stevens, TCP/IP Illustrated, Volume 1: The Protocols. Ann Arbor: Addison-Wesley, 2011, pp. 715-730.
  14. J. Semke, J. Mahdavi, and M. Mathis, "Automatic TCP buffer tuning," ACM SIGCOMM Computer Communication Review, vol. 28, no. 4, 1998, pp. 315-323. https://doi.org/10.1145/285243.285292
  15. Linux Tuning - ESnet https://fasterdata.es.net/host-tuning/linux/
  16. S. Gorshe, A. Raghavan, T. Starr, and S. Galli, Broadband Access_ Wireline and Wireless - Alternatives for Internet Services. Noida: John Wiley & Sons, 2014, pp. 227-236.
  17. J. Wagner, INFORMATION ON WIDEBAND VLBI OPERATION. Daejeon: Korea Astronomy and Space Science Institute, 2015, pp. 21-22.
  18. About RRDtool - https://oss.oetiker.ch/rrdtool/