HP: Hybrid paxos for WANs

Dan Dobre, Matthias Majuntke, Marco Serafini, Neeraj Suri

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Citations (Scopus)


Implementing a fault-tolerant state machine boils down to reaching consensus on a sequence of commands. In wide area networks (WANs), where network delays are typically large and unpredictable, choosing the best consensus protocol is difficult. During normal operation, Classic Paxos (CP) requires three message delays, whereas Fast Paxos (FP) requires only two. However, when collisions occur, due to interfering commands issued concurrently, FP requires four extra message delays. In addition, FP uses larger quorums than CP. Therefore, CP can outperform FP in many situations. We present Hybrid Paxos (HP), a consensus protocol that combines the features of FP and CP. HP implements generalized consensus, where collisions are caused only by interfering commands. In the absence of collisions HP requires two message delays, and only one extra message delay otherwise. Our evaluation shows that when collisions are rare, the latency of HP reaches the theoretical minimum. When collisions are frequent, HP behaves like CP.

Original languageEnglish
Title of host publicationEDCC-8 - Proceedings of the 8th European Dependable Computing Conference
Number of pages10
Publication statusPublished - 12 Jul 2010
Externally publishedYes
Event8th European Dependable Computing Conference, EDCC-8 - Valencia, Spain
Duration: 28 Apr 201030 Apr 2010


Other8th European Dependable Computing Conference, EDCC-8


ASJC Scopus subject areas

  • Theoretical Computer Science
  • Software
  • Computer Graphics and Computer-Aided Design

Cite this

Dobre, D., Majuntke, M., Serafini, M., & Suri, N. (2010). HP: Hybrid paxos for WANs. In EDCC-8 - Proceedings of the 8th European Dependable Computing Conference (pp. 117-126). [5474190] https://doi.org/10.1109/EDCC.2010.23