Masters’ Student Project and Internship

Advisor : Marc Shapiro, Senior Researcher at INRIA-LIP6

Introduction

Data replication is necessary for co-operative work. When updates occur, keeping replicas consistent is a problem, and it appears necessary to take data semantics into account. We use the Action-Constraint Framework (ACF) to describe both application semantics and replication protocols.

We are developing the Telex middleware based on ACF. Actions (operations) submitted at some site are recorded in its log. Semantic constraints, relating different actions, are also recorded in the log. Sites exchange their logs and each site maintains its own view of the shared documents.

Logging enables a new approach to security. A user might perform illegal actions locally, but remote sites may choose to ignore those actions, even though they are in the log. This would be the case when determined that a user performed illegal actions (even in the past). However, it is necessary to study the interactions of such security mechanisms with consistency and garbage collection.

Objectives

This internship aims to design and implement generic mechanisms in Telex, enabling different security policies.

Work programme

The internship shall start with a brief study of the state of the art in co-operative development environments, in order to compare their approaches to security. Then the intern will design and develop basic security mechanisms in our Telex middleware, and to use them to implement a specific security policy. Then he/she shall evaluate the performance by simulation and by using real traces from co-operative development environments such as CVS or BSCW.

Pre-requisites

To have a working knowledge of Java, to be interested in security in distributed systems and in optimistic replication.

Location

The work will take place in the Laboratoire d’Informatique de Paris-6 (LIP6 : the Paris-6 University Computer Science Laboratory), in Paris, France. The Regal group is affiliated to both INRIA Paris-Rocquencourt and LIP6.

To apply

Please contact Marc Shapiro with the following information :

 A resume or curriculum vitae.

 The list of courses followed in the past two years, and your grades.

 The name and contact information of two references, i.e., people who know you professionally (e.g. professors, advisors, or employers), and who we may contact for a recommendation.

 A short essay (1—2 pages) on the proposed topic. It is free form, but here are some suggestions. Using the bibliography and your technical knowledge, motivate your interest in the topic and your qualifications for it ; discuss scientific and practical issues, problems and difficulties, possible solutions, relate the issues with your own experience, etc.

 If applicable : any programs, articles or reports you wrote in the past year (in either English or French).

Bibliography

 Telex : A Semantic Platform for Cooperative Application Development. Benmouffok, Busca, Marquès, Shapiro, Sutra, Tsoukalas. Conférence Française de Systèmes d’Exploitation (CFSE), Toulouse, September 2009. PDF

 Effective and Efficient Compromise Recovery for Weakly Consistent Replication. Mahajan et al. EuroSys 2009, April 2009. More info.

Start date

As soon as possible.