Towards Verification of the Pastry Protocol Using TLA + 

  • Tianxiang Lu
  • Stephan Merz
  • Christoph Weidenbach
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6722)


Pastry is an algorithm that provides a scalable distributed hash table over an underlying P2P network. Several implementations of Pastry are available and have been applied in practice, but no attempt has so far been made to formally describe the algorithm or to verify its properties. Since Pastry combines rather complex data structures, asynchronous communication, concurrency, resilience to churn and fault tolerance, it makes an interesting target for verification. We have modeled Pastry’s core routing algorithms and communication protocol in the specification language TLA + . In order to validate the model and to search for bugs we employed the TLA +  model checker tlc to analyze several qualitative properties. We obtained non-trivial insights in the behavior of Pastry through the model checking analysis. Furthermore, we started to verify Pastry using the very same model and the interactive theorem prover tlaps for TLA + . A first result is the reduction of global Pastry correctness properties to invariants of the underlying data structures.


formal specification model checking verification methods network protocols 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Bakhshi, R., Gurov, D.: Verification of peer-to-peer algorithms: A case study. Electr. Notes Theor. Comput. Sci. 181, 35–47 (2007)CrossRefGoogle Scholar
  2. 2.
    Borgström, J., Nestmann, U., Onana, L., Gurov, D.: Verifying a structured peer-to-peer overlay network: The static case. In: Priami, C., Quaglia, P. (eds.) GC 2004. LNCS, vol. 3267, pp. 250–265. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  3. 3.
    Castro, M., Costa, M., Rowstron, A.I.T.: Performance and dependability of structured peer-to-peer overlays. In: International Conference on Dependable Systems and Networks (DSN 2004), Florence, Italy, pp. 9–18. IEEE Computer Society Press, Los Alamitos (2004)CrossRefGoogle Scholar
  4. 4.
    Chaudhuri, K., Doligez, D., Lamport, L., Merz, S.: Verifying safety properties with the TLA +  proof system. In: Giesl, J., Hähnle, R. (eds.) IJCAR 2010. LNCS, vol. 6173, pp. 142–148. Springer, Heidelberg (2010)CrossRefGoogle Scholar
  5. 5.
    Haeberlen, A., Hoye, J., Mislove, A., Druschel, P.: Consistent key mapping in structured overlays. Technical Report TR05-456, Rice University, Department of Computer Science (August 2005)Google Scholar
  6. 6.
    Lamport, L.: Specifying Systems, The TLA+ Language and Tools for Hardware and Software Engineers. Addison-Wesley, Reading (2002)Google Scholar
  7. 7.
    Lu, T., Merz, S., Weidenbach, C.: Towards verification of the pastry protocol using TLA+. Technical Report MPI-I-2011-RG1-002, Max-Planck-Institute für Informatik (April 2011)Google Scholar
  8. 8.
    Rice University and Max-Planck Institute for Software Systems. Pastry: A substrate for peer-to-peer applications,
  9. 9.
    Rowstron, A., Druschel, P.: Pastry: Scalable, distributed object location and routing for large-scale peer-to-peer systems. In: IFIP/ACM International Conference on Distributed Systems Platforms (Middleware), pp. 329–350 (November 2001)Google Scholar
  10. 10.
    Velipasalar, S., Lin, C.H., Schlessman, J., Wolf, W.: Design and verification of communication protocols for peer-to-peer multimedia systems. In: IEEE Intl. Conf. Multimedia and Expo (ICME 2006), Toronto, Canada, pp. 1421–1424. IEEE, Los Alamitos (2006)CrossRefGoogle Scholar
  11. 11.
    Yu, Y., Manolios, P., Lamport, L.: Model checking TLA+ specifications. In: Pierre, L., Kropf, T. (eds.) CHARME 1999. LNCS, vol. 1703, pp. 54–66. Springer, Heidelberg (1999)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Tianxiang Lu
    • 1
    • 2
  • Stephan Merz
    • 2
  • Christoph Weidenbach
    • 1
  1. 1.Max-Planck-Institut für InformatikSaarbrückenGermany
  2. 2.INRIA Nancy & LORIANancyFrance

Personalised recommendations