Section: New Results

Computing on Hybrid Distributed Infrastructure

Participants : Simon Delamare, Gilles Fedak, José Saray, Anthony Simonet.

SpeQuloS: Providing Quality-of-Service to Desktop Grids using Cloud resources

EDGI is an FP7 European project, following the successful FP7 EDGeS project, whose goal is to build a Grid infrastructure composed of "Desktop Grids", such as BOINC or XtremWeb, where computing resources are provided by Internet volunteers, and "Service Grids", where computing resources are provided by institutional Grid such as EGI, gLite, Unicore and "Clouds systems" such as OpenNebula and Eucalyptus, where resources are provided on-demand. The goal of the EDGI project is to provide an infrastructure where Service Grids are extended with public and institutional Desktop Grids and Clouds.

The main limitation with the current infrastructure is that it cannot give any QoS support for applications running in the Desktop Grid (DG) part of the infrastructure. For example, a public DG system enables clients to return work-unit results in the range of weeks. Although there are EGI applications (e.g., the fusion community's applications) that can tolerate such a long latency most of the user communities want much shorter deadlines.

In 2011, we have developed the SpeQuloS middleware to solve this critical problem. Providing QoS features even in Service Grids is hard and not solved yet satisfactorily. It is even more difficult in an environment where there are no guaranteed resources. In DG systems, resources can leave the system at any time for a long time or forever even after taking several work-units with the promise of computing them. Our approach is based on the extension of DG systems with Cloud resources. For such critical work-units the SpeQuloS system is able to dynamically deploy fast and trustable clients from some Clouds that are available to support the EDGI DG systems. It takes the right decision about assigning the necessary number of trusted clients and Cloud clients for the QoS applications. In 2012, we have conducted extensive simulations to evaluate various strategies of Cloud resources provisioning. Results show that SpeQuloS improve the QoS of BoTs on three aspects: it reduces the makespan by removing the tail effect, it improves the execution stability and it allows to accurately predicts the BoT completion time [14] , [21] , [35] . The software have now been delivered to the partners and run in production in the European Desktop Grid Infrastructure.

Scheduling on Hybrid Distributed Computing Infrastructures

In collaboration with the Mircea Moca, from the Babes-Bolyai University of Cluj-Napoca (Romania), we have investigated new scheduling algorithms for pull-based scheduler, which relies on Promethee method. We have shown that these heuristics perform efficiently on three different kinds of infrastructures, namely Grids, Clouds and Desktop Grids [23] .