Sérgio Filipe Garrau dos Santos Almeida

Geo-Replication in Large Scale Cloud Computing Applications

Tese submetida para provas de mestrado em Engenharia Informática e de Computadores Instituto Superior Técnico, Universidade Técnica de Lisboa.


Managing the tradeoffs among consistency, availability, and scalability, namely in systems supporting Geo-replication, is one of the most challenging aspects of the design of distributed datastores for cloud-computing applications. As a result, several combinations of different con- sistency guarantees and replication protocols have been proposed in the last few years. The work described in this report makes a step forward in this path, by proposing a novel dis- tributed datastore design, named ChainReaction, that offers causal+ consistency, with high performance, fault-tolerance, and scalability. We introduce a new replication technique based on Chain Replication, a very interesting replication technique that provides linearizability and high performance in a very simple way. Our approach avoids the bottlenecks of linearizability while providing competitive performance when compared with systems merely offering eventual consistency. Furthermore, ChainReaction can be deployed both in a single datacenter and Geo- replicated scenarios, over multiple datacenters. We have experimentally evaluated the benefits of our approach by applying the Yahoo Cloud Serving Benchmark to a prototype deployment that includes our own solution as well as Apache Cassandra and FAWN-KV. Finally, our solution also provides a transactional construct that allows a client obtain the value of multiple objects in a consistent way. Experimental results show that this extension has no negative impact on the performance of ChainReaction.


Geo-Replication in Large Scale Cloud Computing Applications
Sérgio Filipe Garrau dos Santos Almeida
MSc Thesis. Instituto Superior Técnico, Universidade Técnica de Lisboa.
October, 2012.
Available BibTeX, MSC Thesis, extended abstract of the thesis, and mid-term report.
ChainReaction: uma Variante de Replicação em Cadeia com Coerência Causal+.
S. Almeida, J. Leitão, and L. Rodrigues.
Actas do quarto Simpósio de Informática (Inforum), Caparica, Portugal, Sep, 2012
Available BibTeX, extended report (pdf).
ChainReaction a Causal+ Consistent Datastore based on Chain Replication.
S. Almeida, J. Leitão and L. Rodrigues.
Proceedings of the EuroSys 2013, Prague, Czech Republic, April 2013.
Available BibTeX, abstract (html).

Luís Rodrigues