Invited talks

Verifying Eventual Consistency of Optimistic Replication Systems
Ahmed Bouajjani, Univ. Paris Diderot (Paris 7)
We address the verification problem of eventual consistency of optimistic replication systems. Such systems are typically used to implement distributed data structures over large scale networks. We introduce a formal definition of eventual consistency that applies to a wide class of existing implementations, including the ones using speculative executions. Then, we reduce the problem of checking eventual consistency to reachability and model checking problems. This reduction enables the use of existing verification tools for message-passing programs in the context of verifying optimistic replication systems.This is a joint work with Constantin Enea and Jad Hamza. 

Automating the choice of consistency using SIEVE
Rodrigo Rodrigues, Universidade NOVA de Lisboa
The increasing use of (geo-)replication for improving performance highlighted the tension between consistency and performance. In this context, several proposals allow operations to run at different consistency levels, aiming to approximate the best of both worlds. However, the burden of deciding which level to use for each operation lies on the programmer. We present SIEVE, a tool that relieves Java programmers from this decision, allowing applications to automatically use weak consistency for better performance when possible, while resorting to strong consistency when necessary. Taking as input a set of application-specific invariants and some annotations regarding merge semantics, SIEVE performs a combination of static and dynamic analysis, offline and at runtime, to determine when to use strong consistency to preserve these invariants and when to use eventually consistent commutative replicated data types (CRDTs). 

Cloud Types: Robust Abstractions for Replicated Shared Data
Sebastian Burckhardt, Microsoft Research

In the age of cloud-connected mobile devices, users want responsive apps that read and write shared data everywhere, at all times, even if network connections are slow or unavailable. Cloud types lets programmers declare, read, and update shared structured data while hiding tricky consistency issues related to update propagation and conflict resolution. In this talk, I will examine (1) how to understand the weak consistency model operationally, (2) anti-patterns where consistency pitfalls continue to lurk, and (3) how to use robust streaming and optimal delta reduction to implement the system efficiently and reliably. 


Session 1 - 8:30 - 10:30 - Replicated objects and composition

Cloud Types: Robust Abstractions for Replicated Shared Data, Sebastian Burckhardt (invited talk)

Riak DT Map: A Composable, Convergent Replicated Dictionary, Russell Brown, Sean Cribbs, Sam Elliott and Christopher Meiklejohn

An open implementation of Cloud Types for the Web, Tim Coppieters, Laure Philips, Tom Van Cutsem and Wolfgang De Meuter

Efficient State-based CRDTs by Decomposition (Work in progress report), Paulo Sérgio Almeida, Ali Shoker and Carlos Baquero

Triton: a Peer-Assisted Cloud Storage System, Antonio Davoli and Alessandro Mei

Beyond Replicated Storage: Eventually-Consistent Distributed Data Structures, Konrad Iwanicki

Coffee break - 10:30 - 11:00

Session 2 - 11:00 - 12:30 - Operations and logging

Closing The Performance Gap between Causal Consistency and Eventual Consistency, Jiaqing Du, Calin Iorgulescu, Amitabha Roy and Willy Zwaenepoel

Simizer: evaluating consistency trade offs through simulation, Sylvain Lefebvre, Sathiya Prabhu Kumar and Raja Chiky

Making operation based CRDTs operation based (Work in progress report), Carlos Baquero, Paulo Sérgio Almeida and Ali Shoker

Citrea and Swarm: partially ordered op logs in the browser, Victor Grishchenko

Merging OT and CRDT Algorithms, Mehdi Ahmed-Nacer, Pascal Urso, Nuno Preguica and Valter Balegas

Lunch - 12:30 - 14:00

Session 3 - 14:00 - 15:30 - Consistency trade-offs

Automating the choice of consistency using SIEVE, Rodrigo Rodrigues (invited talk)

Having Your Cake and Eating it Too: Combining Strong and Eventual Consistency, Paweł T. Wojciechowski and Konrad Siek

The Case for Fast and Invariant-Preserving Geo-Replication, Valter Balegas and Mahsa Najafzadeh

Bridging the Gap: Opportunities in Coordination-Avoiding Database Research, Peter Bailis, Alan Fekete, Michael J. Franklin, Ali Ghodsi, Joseph M. Hellerstein and Ion Stoica

Coffee break + poster session - 15:30 - 16:30

Session 4 - 16:30 - 18:00 - Correctness

Verifying Eventual Consistency of Optimistic Replication Systems, Ahmed Bouajjani, (invited talk)

Towards Verifying Eventually Consistent Applications, Burcu Külahçıoğlu Özkan, Erdal Mutlu and Serdar Tasiran

A Generic Model of Consistency Guarantees for Replicated Services, Szymon Francuzik, Cezary Sobaniec and Dariusz Wawrzyniak

On The Composability of the Riak DT Map: Expanding From Embedded To Multi-Key Structures (work in progress report), Christopher Meiklejohn