Università della Svizzera italiana

Building global and scalable systems with atomic multicast

Benz, Samuel ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2018 ; 2018INFO003.

The rise of worldwide Internet-scale services demands large distributed systems. Indeed, when handling several millions of users, it is common to operate thousands of servers spread across the globe. Here, replication plays a central role, as it contributes to improve the user experience by hiding failures and by providing acceptable latency. In this thesis, we claim that atomic multicast,...

Università della Svizzera italiana

On the many faces of atomic multicast

Coelho, Paulo ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2019 ; 2019INFO004.

Many current online services need to serve clients distributed across geographic areas. Coordinating highly available and scalable geographically distributed replicas, however, is challenging. While State Machine Replication is the most direct way of achieving availability, no scalability comes from the traditional approach. Typically, scalability is obtained by partitioning the original...

Università della Svizzera italiana

Consensus protocols exploiting network programmability

Dang, Huynh Tu ; Soulé, Robert (Dir.) ; Pedone, Fernando (Codir.)

Thèse de doctorat : Università della Svizzera italiana, 2019 ; 2019INFO003.

Services rely on replication mechanisms to be available at all time. The service demanding high availability is replicated on a set of machines called replicas. To maintain the consistency of replicas, a consensus protocol such as Paxos or Raft is used to synchronize the replicas' state. As a result, failures of a minority of replicas will not affect the service as other non-faulty replicas...

Università della Svizzera italiana

High-performance state-machine replication

Jalili Marandi, Parisa ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2014 ; 2014INFO006.

Replication, a common approach to protecting applications against failures, refers to maintaining several copies of a service on independent machines (replicas). Unlike a stand-alone service, a replicated service remains available to its clients despite the failure of some of its copies. Consistency among replicas is an immediate concern raised by replication. In effect, an important factor...

Università della Svizzera italiana

Building blocks for leveraging in-network computing

Jepsen, Theo ; Soulé, Robert (Dir.) ; Pedone, Fernando (Codir.)

Thèse de doctorat : Università della Svizzera italiana, 2020 ; 2020INFO012.

With the end of Moore's law and Dennard scaling, applications no longer enjoy performance improvements by simply waiting for the next generation of CPUs. This has led to the rise of domain-specific computing. As developers try to squeeze more performance out of applications, they have offloaded application functionality to specialized hardware, such as GPUs, FPGAs and ASICs. Programming these...

Università della Svizzera italiana

A transport protocol for best-effort content-based networks

Malekpour, Amirhossein ; Carzaniga, Antonio ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2012 ; 2012INFO007.

Content-based publish/subscribe (or simply content-based) networking is a relatively new communication paradigm compared to IP networking, with a different approach to addressing network hosts. In content- based networking addressing as well as information dissemination center around information and interests. A host's address is represented by its interest and information is routed by a...

Università della Svizzera italiana

On non-intrusive workload-aware database replication

Narváez, Vaide ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2009 ; 2009INFO002.

Performance and high-availability are the crucial factors in the development of nowadays distributed database systems. Both of these challenges are commonly addressed by means of the same technique, database replication. The overall throughput of the system is increased by leveraging parallel computation on different sites, and in case of replica failures, availability is improved by...

Università della Svizzera italiana

High performance deferred update replication

Sciascia, Daniele ; Pedone, Fernando (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2015 ; 2015INFO004.

Replication is a well-known approach to implementing storage systems that can tolerate failures. Replicated storage systems are designed such that the state of the system is kept at several replicas. A replication protocol ensures that the failure of a replica is masked by the rest of the system, in a way that is transparent to its users. Replicated storage systems are among the most...