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Title: Applications and Network in Data Centers: Friends or Foes?

Abstract: Since the early days of networks, a basic principle has been that applications treat the network as a black box. An application injects a packet with a destination address and the network delivers the packet. This principle has served us well, and has enabled the Internet to scale to billions of devices using networks owned by competing companies and running applications developed by different parties. However, this approach might not be optimal for large-scale Internet data centers, such as those run by Amazon, Google, Microsoft and Facebook, in which all the components are controlled by a single entity.

In this talk, I will describe two examples where a richer interaction between applications and network is beneficial for both. First, I will briefly overview our recent research in the context of providing applications with predictable performance in multi-tenant data centers. Then, I will describe more extensively CamCube, a recent project in collaboration with Microsoft Research, in which, we have been looking at a different approach to build data centers, borrowing ideas from the fields of high performance parallel computing, distributed systems and networking. We use a direct-connect topology, similar to those used in HPC, and a novel networking stack, which supports a key-based routing functionality. By providing applications with a more fine-grained control on network resources, CamCube enables increasing performance and reducing development complexity and cluster costs. I will describe and motivate its peculiar design choices and then discuss a number of services that we implemented on CamCube. These include a MapReduce service that provides significant higher performance than existing solutions running on traditional clusters.

Bio: Paolo Costa holds an Imperial’s fellowship at the Department of Computing of Imperial College London. Before joining Imperial, he spent 2.5 years in the Systems and Networking Group of the Microsoft Research Lab in Cambridge. Prior to that, he was a Postdoctoral Researcher in the Computer Systems group at Vrije Universiteit Amsterdam. Paolo holds a M. Sc. and Ph.D. degree in Computer Engineering from the Politecnico di Milano, received, respectively, in 2002 and 2006.

Where: INRIA Rennes – Salle Sardaigne, Batiment 12 F, Campus de Beaulieu

When: On Wed 08-02-2012, at 2pm (until 3pm)

Organized by: ASAP Team – INRIA Rennes

Please confirm your presence by sending an email to: davide.frey@inria.fr

Title:
The Battle for Privacy
Abstract:
This talk is about attacking and defending IP privacy; or, in other
words, violating your boss’ privacy and protecting Wikileaks’ sources.
First, I discuss how to reverse engineer Skype to find out the IP
address of a targeted person.  This could be exploited for many
malicious purposes such as finding out whether your boss is
downloading copyrighted-porn material.  This privacy attack can be
scaled to track, for example, all users working for a large
corporation such the Universal music group.  Furthermore, the attack
can be launched from the comfort of one’s home, without any legal
power, and without the targeted users knowing.  (The story goes that
the first author of this research used this attack to track his
Ph.D. committee.)
Second, I present a system for efficiently defending against IP-based
privacy attacks, even when the attacker is a powerful government such
as the USA. I motivate our novel design by showing that onion routing,
the reference design for IP anonymity, has fundamental scaling issues
when defending against an attacker able to analyze packet logs.  On
the other hand, I show that our design scales with the number of users
while being more efficient than existing solutions.  By combining
anonymity and efficiency, we expect our system to appeal to regular
Internet users, such as visitors of the late MegaUpload, and
whistleblowers alike.
Bio:
Stevens Le Blond holds a M.Sc. from Vrije Universiteit, Amsterdam and
a Ph.D. from INRIA Sophia Antipolis. Stevens seeks to tackle
high-risk/high-impact research problems in the system and networking
areas. At the moment, he believes that many such problems lie in
online privacy.  After enjoying sun bathing in Nice, Stevens is now
enjoying actual bathing in Germany where he’s a postdoc in Paul
Francis’ group at MPI-SWS.

Title:
——-
Resource provisioning for complex Web applications

Abstract:
————-
Dynamic resource provisioning aims at maintaining the end-to-end response time of a web application within a pre-defined range (Service Level Objective, SLO). Provisioning resources for applications composed of multiple services remains a challenge. When the SLO is violated, one must decide /which/ service(s) should be re-provisioned for optimal effect. We propose to assign an SLO only to the front-end service. Other services are not given any particular response time objectives. Services are autonomously responsible for their own provisioning operations and collaboratively negotiate performance objectives with each other to decide the provisioning service(s). After presenting the resource provisioning techniques themselves, I will discuss their application and implementation in the context of the ConPaaS runtime environment for elastic Cloud applications.

Bio:
——
Guillaume Pierre is an associate professor at VU University Amsterdam. His research focuses on the management of very large-scale distributed systems. He particularly studied Web applications as a good example of demanding large-scale systems and Cloud computing platforms. His research addresses a variety of questions such as how to make applications scale, how to control their non-functional properties, and how to design large-scale decentralized infrastructures where they can be deployed.

Tolérer les fautes transitoires, permanentes et intermittentes

Lorsque la taille d’un système réparti devient importante ou lorsque ce système est déployé dans un environnement non contrôlé, la probabilité que certains éléments du système subissent des fautes (panne, corruption de mémoire, piratage, …) devient non négligeable. Ces fautes peuvent être classifiées en fonction de leur durée, de leur étendue et de leur nature. Dans ce séminaire, nous nous intéressons aux systèmes répartis capables de tolérer simultanément plusieurs types de fautes à travers l’étude de trois problèmes fondamentaux. Nous présentons ainsi un protocole réparti simulant un registre atomique mono-écrivan multi-lecteurs en présence de fautes transitoires et de fautes permanentes de type crash. Ce protocole repose sur deux outils ré-utilisables : un protocole de communication et un système d’estampillage borné. Ensuite, nous proposons une étude de la synchronisation faible d’horloges logiques en présence de fautes transitoires et de fautes intermittentes Byzantines. Finalement, nous définissons trois nouveaux concepts de tolérance pour les systèmes répartis sujets à des fautes transitoires et des fautes intermittentes Byzantines. Nous donnons un protocole de construction d’une vaste classe d’arbres couvrants optimal selon ces trois concepts.

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