Transiently Consistent SDN Updates: Being Greedy is Hard

  • Saeed Akhoondian Amiri
  • Arne Ludwig
  • Jan Marcinkowski
  • Stefan Schmid
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9988)

Abstract

The software-defined networking paradigm introduces interesting opportunities to operate networks in a more flexible yet formally verifiable manner. Despite the logically centralized control, however, a Software-Defined Network (SDN) is still a distributed system, with inherent delays between the switches and the controller. Especially the problem of changing network configurations in a consistent manner, also known as the consistent network update problem, has received much attention over the last years. This paper revisits the problem of how to update an SDN in a transiently consistent, loop-free manner. First, we rigorously prove that computing a maximum (“greedy”) loop-free network update is generally NP-hard; this result has implications for the classic maximum acyclic subgraph problem (the dual feedback arc set problem) as well. Second, we show that for special problem instances, fast and good approximation algorithms exist.

References

  1. 1.
    Brandt, S., Förster, K.-T., Wattenhofer, R.: On consistent migration of flows in SDNs. In: Proceedings of IEEE INFOCOM (2016)Google Scholar
  2. 2.
    Bu, T., Gao, L., Towsley, D.: On characterizing BGP routing table growth. Comput. Netw. 45(1), 45–54 (2004)CrossRefGoogle Scholar
  3. 3.
    Canini, M., Kuznetsov, P., Levin, D., Schmid, S.: A distributed and robust SDN control plane for transactional network updates. In: Proceedings of IEEE INFOCOM (2015)Google Scholar
  4. 4.
    Chen, J., Liu, Y., Lu, S., O’sullivan, B., Razgon, I.: A fixed-parameter algorithm for the directed feedback vertex set problem. J. ACM 55(5), 21:1–21:19 (2008)Google Scholar
  5. 5.
    Dudycz, S., Ludwig, A., Schmid, S.: Can’t touch this: consistent network updates for multiple policies. In: Proceedings of 46th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN) (2016)Google Scholar
  6. 6.
    Flum, J., Grohe, M.: Parameterized complexity theory. In: Texts in Theoretical Computer Science. An EATCS Series. Springer, Heidelberg (2006)Google Scholar
  7. 7.
    Förster, K.-T., Mahajan, R., Wattenhofer, R.: Consistent updates in software defined networks: on dependencies, loop freedom, and blackholes. In: Proceedings of 15th IFIP Networking (2016)Google Scholar
  8. 8.
    Förster, K.-T., Wattenhofer, R.: The power of two in consistent network updates: hard loop freedom, easy flow migration. In: Proceedings of 25th International Conference on Computer Communication and Networks (ICCCN) (2016)Google Scholar
  9. 9.
    Ghorbani, S., Godfrey, B.: Towards correct network virtualization. In: Proceedings of ACM HotSDN, pp. 109–114 (2014)Google Scholar
  10. 10.
    Jin, X., Liu, H., Gandhi, R., Kandula, S., Mahajan, R., Rexford, J., Wattenhofer, R., Zhang, M.: Dionysus: dynamic scheduling of network updates. In: Proceedings of ACM SIGCOMM (2014)Google Scholar
  11. 11.
    Kann, V.: On the approximability of NP-complete optimization problems. Ph.D. thesis (1992)Google Scholar
  12. 12.
    Kuzniar, M., Peresíni, P., Kostic, D.: Providing reliable FIB update acknowledgments in SDN. In: Proceedings of 10th ACM CoNEXT, pp. 415–422 (2014)Google Scholar
  13. 13.
    Kuźniar, M., Perešíni, P., Kostić, D.: What you need to know about SDN flow tables. In: Mirkovic, J., Liu, Y. (eds.) PAM 2015. LNCS, vol. 8995, pp. 347–359. Springer, Heidelberg (2015)Google Scholar
  14. 14.
    Ludwig, A., Dudycz, S., Rost, M., Schmid, S.: Transiently secure network updates. In: Proceedings of ACM SIGMETRICS (2016)Google Scholar
  15. 15.
    Ludwig, A., Marcinkowski, J., Schmid, S.: Scheduling loop-free network updates: it’s good to relax! In: Proceedings of ACM Symposium on Principles of Distributed Computing (PODC) (2015)Google Scholar
  16. 16.
    Ludwig, A., Rost, M., Foucard, D., Schmid, S.: Good network updates for bad packets: waypoint enforcement beyond destination-based routing policies. In: Proceedings of ACM Workshop on Hot Topics in Networks (HotNets) (2014)Google Scholar
  17. 17.
    Mahajan, R., Wattenhofer, R.: On consistent updates in software defined networks. In: Proceedings of ACM HotNets (2013)Google Scholar
  18. 18.
    Padon, O., Immerman, N., Karbyshev, A., Lahav, O., Sagiv, M., Shoham, S.: Decentralizing SDN policies. In: Proceedings of 42nd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL), pp. 663–676 (2015)Google Scholar
  19. 19.
    Reitblatt, M., Foster, N., Rexford, J., Schlesinger, C., Walker, D.: Abstractions for network update. In: Proceedings of ACM SIGCOMM, pp. 323–334 (2012)Google Scholar
  20. 20.
    Qazi, Z., et al.: Simple-fying middlebox policy enforcement using SDN. In: Proceedings of ACM SIGCOMM (2013)Google Scholar
  21. 21.
    Zhou, W., (Kevin) Jin, D., Croft, J., Caesar, M., Godfrey, P.B.: Enforcing customizable consistency properties in software-defined networks. In: Proceedings of 12th USENIX Symposium on Networked Systems Design and Implementation (NSDI), pp. 73–85 (2015)Google Scholar

Copyright information

© Springer International Publishing AG 2016

Authors and Affiliations

  • Saeed Akhoondian Amiri
    • 1
  • Arne Ludwig
    • 1
  • Jan Marcinkowski
    • 2
  • Stefan Schmid
    • 3
  1. 1.Technical University BerlinBerlinGermany
  2. 2.University of WroclawWroclawPoland
  3. 3.Aalborg UniversityAalborgDenmark

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