Section: New Results
Experimentation, Emulation, Reproducible Research
This section covers our work on experimentation on testbeds (mainly Grid'5000), on emulation (mainly around the Distem emulator), and on Reproducible Research.
Grid'5000 design and evolutions
Participants : Florent Didier, Arthur Garnier, Imed Maamria, Lucas Nussbaum [contact] , Olivier Demengeon [SED] , Teddy Valette [SED] .
The team was again heavily involved in the evolutions and the governance of the Grid'5000 testbed.
Technical team management
Since the beginning of 2017, Lucas Nussbaum serves as the Grid'5000 directeur technique (CTO), managing the global technical team (9 FTE).
We are also heavily involved in the ongoing SILECS project, that aims at creating a new infrastructure on top of the foundations of Grid'5000 and FIT in order to meet the experimental research needs of the distributed computing and networking communities.
Promoting the testbed
In order to promote the testbed to the french devops and sysadmin community, we presented in  an overview of the testbed's capabilities.
We contributed a new feature that will greatly help Big Data experimenters: the ability to reserve disks on nodes, in order to leave large datasets stored on nodes between nodes reservations.
Automated testing of the testbed
In order to ensure that all services remain functional, and that experimental results remain trustworthy and reproducible, we designed an infrastructure to automatically test the testbed and detect misconfigurations, regressions, uncontrolled hardware heterogeneity, etc. This work was described in  and later presented in .
Support for SDN experiments
We started the development of a tool to orchestrate SDN experiments on Grid'5000, combining KaVLAN and OpenVSwitch.
Emulation with Distem
Participants : Alexandre Merlin, Lucas Nussbaum [contact] .
The ADT SDT project started in March. Initial work focused on improving the software developing infrastructure by adding automated regression tests on both correctness and performance. This should allow a new release in early 2018.
I/O access patterns analysis with eBPF
Participants : Abdulqawi Saif, Lucas Nussbaum [contact] , Ye-Qiong Song.
In the context of Abdulqawi Saif's CIFRE PhD (with Xilopix), we explored the relevance of an emerging instrumentation technology for the Linux kernel, eBPF, and used it to analyze I/O access patterns of two popular NoSQL databases. A publication on this topic is expected in early 2018.
Performance study of public clouds
Participants : Souha Bel Haj Hassine, Lucas Nussbaum [contact] .
We worked on clouds performance in the context of an ongoing collaboration with CloudScreener, a French startup founded in 2012 that has developed tools for cloud price and performance benchmarks and automated cloud recommendation to optimize the decision making process in the context of cloud computing. We designed methods and tools to do performance evaluation of public clouds focusing on (1) outlining performance variability over time; (2) identifying adverse strategies that might be deployed by cloud providers in order to vary the performance level over time.
Testbeds federation and collaborations in the testbeds community
The Fed4FIRE+ H2020 project started in January 2017 and will run until the end of September 2021. This project aims at consolidating the federation of testbeds in Europe of which Grid'500 is a member.
We are also active in the GEFI initiative that aims at building links between the US testbeds community (GENI) and their european (FIRE), japanese and brazilian counterparts. We participated in the annual GEFI meeting where gave two talks  and chaired the session on reproducibility.
Experimentation and reproducible research
In addition to the work already mentioned on testbed testing , , we worked on a survey of testbeds and their features for reproducible research . We also gave several talks on reproducible research and testbeds at École ARCHI , École RESCOM , and Inria webinars on Reproducible Research .