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Lucas Nussbaum's Homepage

Assistant professor at Université Nancy 2. Researcher in the AlGorille team, which is a joint team of the LORIA laboratory and INRIA Nancy - Grand Est.

Je suis Maître de Conférences à l'IUT Nancy-Charlemagne (Université Nancy 2). Mes activités de recherche s'effectuent au sein du LORIA, dans l'équipe AlGorille.

Précédemment, j'étais doctorant au Laboratoire d'Informatique de Grenoble (LIG), dans l'équipe MESCAL, puis ATER à l'Université Claude Bernard Lyon 1 (mes activités de recherche s'effectuaient alors au Laboratoire de l'Informatique du Parallélisme (LIP), à l'ENS Lyon, dans l'équipe RESO).

Contact information

Email: lucas.nussbaum@loria.fr

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Ireland, 2007

Internship proposals / Propositions de stages

Research / Recherche

Topic: methods and tools for the evaluation of distributed systems

Publications

Usually also available on hal.archives-ouvertes.fr

International journals, conferences and workshops

(Also includes some research reports, but only when there's no other corresponding article)

National (french) journals, conferences and workshops

Thèse / PhD Thesis

Talks

Non-academic talks

Being involved in the Free Software community, I often give talks at various conferences, mostly about Debian and Ubuntu. Here are some slides for the most recent of those talks.

Others

Teaching / Enseignement

Je suis Maître de conférences à l'Université Nancy 2, affecté à l'IUT Nancy-Charlemagne.

Liens utiles

Useful Resources

Katapult

Katapult is a simple script allowing to automatically deploy nodes, check that they work properly, and then run a specified script on them.

It has its own homepage.

NISTNet on recent Linux kernels (2.6.26+)

The original NISTNet doesn't work on recent Linux kernels. There are some instructions (and a patch) to make it work on more recent kernels available here, but even this patch fails to work with more recent Linux kernels (apparently it worked until Linux 2.6.24). Here is an updated patch that is known to work with Linux 2.6.26. It applies to nistnet.2.0.12c.tar.gz, and the normal installation instructions work fine, provided that you install the necessary build dependencies (for Debian, at least x-dev libxt-dev libxmu-headers libxaw7-dev libc6-dev-i386 xmkmf xaw3dg-dev).

Another problem is that recent distribution kernels enable HPET, which breaks NISTNet. You need to recompile your kernel to disable it. Here is a patch against Debian's 2.6.26 kernel configuration that is known to work (a simpler diff might work too).

Note: if you are a Grid'5000 user, a sid-x64-base-1.1-nistnet image is available on Orsay (user lnussbaum). Log in as root, cd nistnet-3.0a, run make install, modprobe nistnet, and use cnistnet.

iperf's reverse mode

iperf is a popular tool to measure network throughput. However, it can only be used to measure throughput from the iperf client to the iperf server. This is a problem when one wants to measure the throughput in both directions, and one of the hosts is behind a NAT/firewall. This patch adds a reverse mode, where the data is transfered from the server to the client, allowing to measure the download throughput. This mode is enabled by specifying the -2 option. The patch has been submitted to iperf's authors, but hasn't been included yet.

Linux kernel patch to enable/disable SCTP checksum computation via sysctl

With SCTP, computing CRC32 checksums is known to add a signifiant overhead. Unfortunately, most NICs don't support offloading that computation. To be able to achieve Gigabit-grade bandwidth with SCTP with current hardware, it is required to disable SCTP checksumming. This is only possible by manually modifying the SCTP implementation. This patch adds a module option (no_checksums) that allows to easily disable checksums computation.

Note: This breaks protocol compliance. You won't be able to communicate with hosts where checksums are enabled.

Links

last update: 12/03/2010 - lucas.nussbaum@loria.fr