SLO-ML: A Language for Service Level Objective Modelling in Multi-cloud Applications

Abstract

Cloud modelling languages (CMLs) are designed to assist customers in tackling the diversity of services in the cloud market. While many CMLs have been proposed in the literature, they lack practical support for automating the selection of services based on the specific service level objectives of a customer's application. We put forward SLO-ML, a novel and generative CML to capture service level requirements and, subsequently, to select the services to honour customer requirements and generate the deployment code appropriate to these services. We present the architectural design of SLO-ML and the associated broker that realises the deployment operations. We rigorously evaluate SLO-ML using a mixed methods approach. First, we exploit an experimental case study with a group of researchers and developers using a real-world cloud application. We also assess overheads through an exhaustive set of empirical scalability tests. Through expressing the levels of gained productivity and experienced usability, we highlight SLO-ML's profound potential in enabling user-centric cloud brokers. We also discuss limitations as application requirements grow.

Meeting SLOs in cross-platform NFV

“…It may want to apply security or isolation policies on traffic from these customers using NF chains. In doing so, however, the ISP runs the risk of violating traffic SLOs that it established with its customers because the NFs add processing overhead [9]. In discussions with ISPs, we have found that such SLOs usually have three required components: a minimum rate requirement on aggregate traffic processed by an NF chain, a maximum rate bound that limits bursts, and a maximum delay imposed by the NF chain.…”