17,284 research outputs found
Brief Announcement: Authenticated Consensus in Synchronous Systems with Mixed Faults
Protocols solving authenticated consensus in synchronous networks with Byzantine faults have been widely researched and known to exists if and only if n > 2f for f Byzantine faults. Similarly, protocols solving authenticated consensus in partially synchronous networks are known to exist if n > 3f+2k for f Byzantine faults and k crash faults. In this work we fill a natural gap in our knowledge by presenting MixSync, an authenticated consensus protocol in synchronous networks resilient to f Byzantine faults and k crash faults if n > 2f+k. As a basic building block, we first define and then construct a publicly verifiable crusader agreement protocol with the same resilience. The protocol uses a simple double-send round to guarantee non-equivocation, a technique later used in the MixSync protocol. We then discuss how to construct a state machine replication protocol using these ideas, and how they can be used in general to make such protocols resilient to crash faults. Finally, we prove lower bounds showing that n > 2f+k is optimally resilient for consensus and state machine replication protocols
Partial replication in the database state machine
This paper investigates the use of partial replication in the Database State Machine approach introduced ear- lier for fully replicated databases. It builds on the or- der and atomicity properties of group communication primitives to achieve strong consistency and proposes two new abstractions: Resilient Atomic Commit and Fast Atomic Broadcast. Even with atomic broadcast, partial replication re- quires a termination protocol such as atomic commit to ensure transaction atomicity. With Resilient Atomic Commit our termination protocol allows the commit of a transaction despite the failure of some of the par- ticipants. Preliminary performance studies suggest that the additional cost of supporting partial replica- tion can be mitigated through the use of Fast Atomic Broadcast
H2O: An Autonomic, Resource-Aware Distributed Database System
This paper presents the design of an autonomic, resource-aware distributed
database which enables data to be backed up and shared without complex manual
administration. The database, H2O, is designed to make use of unused resources
on workstation machines. Creating and maintaining highly-available, replicated
database systems can be difficult for untrained users, and costly for IT
departments. H2O reduces the need for manual administration by autonomically
replicating data and load-balancing across machines in an enterprise.
Provisioning hardware to run a database system can be unnecessarily costly as
most organizations already possess large quantities of idle resources in
workstation machines. H2O is designed to utilize this unused capacity by using
resource availability information to place data and plan queries over
workstation machines that are already being used for other tasks. This paper
discusses the requirements for such a system and presents the design and
implementation of H2O.Comment: Presented at SICSA PhD Conference 2010 (http://www.sicsaconf.org/
Hosting Byzantine Fault Tolerant Services on a Chord Ring
In this paper we demonstrate how stateful Byzantine Fault Tolerant services
may be hosted on a Chord ring. The strategy presented is fourfold: firstly a
replication scheme that dissociates the maintenance of replicated service state
from ring recovery is developed. Secondly, clients of the ring based services
are made replication aware. Thirdly, a consensus protocol is introduced that
supports the serialization of updates. Finally Byzantine fault tolerant
replication protocols are developed that ensure the integrity of service data
hosted on the ring.Comment: Submitted to DSN 2007 Workshop on Architecting Dependable System
Authenticated Consensus in Synchronous Systems with Mixed Faults
Protocols solving authenticated consensus in synchronous networks with Byzantine faults have been widely researched and known to exists if and only if for Byzantine faults. Similarly, protocols solving authenticated consensus in partially synchronous networks are known to exist if for Byzantine faults and crash faults.
Currently, the only known synchronous protocol for consensus with a resilience of is a binary consensus protocol. In this work we fill a natural gap in our knowledge by presenting MixSync, an authenticated multivalued consensus protocol in synchronous networks resilient to Byzantine faults and crash faults if . As a basic building block, we first define and then construct a publicly verifiable crusader agreement protocol with the same resilience. The protocol uses a simple double-send round to guarantee non-equivocation, a technique later used in the MixSync protocol. We then discuss how to construct a state machine replication protocol using these ideas, and how they can be used in general to make such protocols resilient to crash faults. Finally, we prove lower bounds showing that is optimally resilient for consensus and state machine replication protocols
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