Università della Svizzera italiana

P-Store : genuine partial replication in wide area networks

Schiper, Nicolas ; Sutra, Pierre ; Pedone, Fernando

Partial replication is a way to increase the scalability of replicated systems since updates only need to be applied to a subset of the system’s sites, thus allowing replicas to handle independent parts of the workload in parallel. In this paper, we propose P-Store, a partial database replication protocol for wide area networks. In P-Store, each transaction T optimistically executes on one...

Università della Svizzera italiana

Fast, flexible, and highly resilient genuine fifo and causal multicast algorithms

Schiper, Nicolas ; Pedone, Fernando

We study the fifo and causal multicast problem, two group-communication abstractions that deliver messages in an order consistent with their context. With fifo multicast, the context of a message m at a process p is all messages that were previously multicast by m’s sender and addressed to p. Causal multicast extends the notion of context to all messages that are causally linked to m by a...

Università della Svizzera italiana

Genuine versus non-genuine atomic multicast protocols

Schiper, Nicolas ; Sutra, Pierre ; Pedone, Fernando

In this paper, we study atomic multicast, a fundamental abstraction for building fault-tolerant systems. We suppose a system composed of data centers, or groups, that host many processes connected through high-end local links; a few groups exist, interconnected through high-latency communication links. In this context, a recent paper has shown that no multicast protocol can deliver messages...

Università della Svizzera italiana

On multicast primitives in large networks and partial replication protocols

Schiper, Nicolas ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2009 ; 2009INFO005.

Recent years have seen the rapid growth of web-based applications such as search engines, social networks, and e-commerce platforms. As a consequence, our daily life activities rely on computers more and more each day. Designing reliable computer systems has thus become of a prime importance. Reliability alone is not sufficient however. These systems must support high loads of client...

Università della Svizzera italiana

Optimistic algorithms for partial database replication

Schiper, Nicolas ; Schmidt, Rodrigo ; Pedone, Fernando

In this paper, we study the problem of partial database replication. Numerous previous works have investigated database replication, however, most of them focus on full replication. We are here interested in genuine partial replication protocols, which require replicas to permanently store only information about data items they replicate. We define two properties to characterize partial...

Università della Svizzera italiana

Solving atomic multicast when groups crash

Schiper, Nicolas ; Pedone, Fernando

In this paper, we study the atomic multicast problem, a fundamental abstraction for building faulttolerant systems. In the atomic multicast problem, the system is divided into non-empty and disjoint groups of processes. Multicast messages may be addressed to any subset of groups, each message possibly being multicast to a different subset. Several papers previously studied this problem either in...

Università della Svizzera italiana

Optimal atomic broadcast and multicast algorithms for wide area networks

Schiper, Nicolas ; Pedone, Fernando

In this paper, we study the atomic broadcast and multicast problems, two fundamental abstractions for building fault-tolerant systems. As opposed to atomic broadcast, atomic multicast allows messages to be addressed to a subset of the processes in the system, each message possibly being multicast to a different subset. We require atomic multicast algorithms to be genuine, i.e., only processes...

Università della Svizzera italiana

A robust and lightweight stable leader election service for dynamic systems

Schiper, Nicolas ; Toueg, Sam

We describe the implementation and experimental evaluation of a fault-tolerant leader election service for dynamic systems. Intuitively, distributed applications can use this service to elect and maintain an operational leader for any group of processes which may dynamically change. If the leader of a group crashes, is temporarily disconnected, or voluntarily leaves the group, the service...