Market competitiveness puts enormous pressures over companies to be agile in providing their offers and adapt to fast changes. In such context, resource dimensioning is an hard and risky task which may lead companies to underprovision their data-center, and therefore be unable to cope with peak loads, or to overprovision it, and not fullfill their ROI. Cloud computing ought to provide such ability. In a previous work, we presented our solution for multi-tier web-based application hosting over a gLite based infrastructure. In this paper, we present a further development of our system towards the Cloud model. A scenario describing our system in action is also discussed.