Investigations of an SLA Support System for Cloud Computing (SLACC)

Abstract

Cloud Providers (CP) and Cloud Users (CU) need to agree on a set of parameters expressed through Service Level Agreements (SLA) for a given Cloud service. However, even with the existence of many CPs in the market, it is still impossible today to see CPs who guarantee, or at least offer, an SLA specification tailored to CU's interests: not just offering percentage of availability, but also guaranteeing, for example, specific performance parameters for a certain Cloud application. Due to (1) the huge size of CPs' IT infrastructures and (2) the high complexity with multiple inter-dependencies of resources (physical or virtual), the estimation of specific SLA parameters to compose Service Level Objectives (SLOs) with trustful Key Performance Indicators (KPIs) tends to be inaccurate. This paper investigates an SLA Support System for CC (SLACC) which aims to estimate in a formalized methodology – based on available Cloud Computing infrastructure parameters – what CPs will be able to offer/accept as SLOs or KPIs and, as a consequence, which increasing levels of SLA specificity for their customers can be reached.