End-to-End Service Quality for Cloud Applications

This paper aims to highlight the importance of end-to-end service quality for cloud services especially for the case of telecom carrier grade services. We will mainly focus on the multi-tenancy aspects (as the enhanced level of resource sharing raises issues in terms of stability and reliability of cloud services) as well as the area of Service Level Agreements for end-to-end scenarios. Our main proposition is that, technology-wise, we have today all the basic building blocks that may enable cloud infrastructures to exhibit stable and predictable performance to customers. However, one of the major obstacles that keep hindering the potential for a worldwide deployment of these technologies and especially for telecom services, is the fact that, in many distributed and cloud computing scenarios, there is not merely a single business entity responsible for the service delivery, but we may have multiple different, unrelated business entities with contrasting and competing requirements, interacting for the provisioning of end-to-end cloud services to customers and finally end users. It is the case, for example, of multiple cloud providers, storage providers and network service providers, that may be involved for the delivery of a distributed cloud service to a community of end users. In this context, setting up proper Service-Level Agreements (SLAs) among the involved players, for delivering strong QoS guarantees to customers, may become overwhelmy challenging. However, the main problems arising in such interactions may be mitigated by a thoughtful intervention of standardization.