Infrastructure-as-a-Service (IaaS) clouds are evolving from offering simple on-demand resources to providing diverse sets of tightly-coupled monolithic services. Like OS kernels of the 1980's and 1990's, these monolithic offerings, albeit rich in features, are significantly constraining users' freedom and control over the underlying-- cloud--resources. For example, we are unaware of a true hybrid cloud, where its users can migrate virtual machines freely across clouds. This paper argues for a new type of IaaS cloud, an xCloud, that builds on ideas from extensible OSs to give users the flexibility to install custom cloud extensions, which can address the limitations outlined above. We describe the design space for xClouds, including a practical approach for transforming today's public clouds into xClouds.
['Dan Williams', 'Eslam Elnikety', 'Mohamed Eldehiry', 'Hani Jamjoom', 'Hai Huang', 'Hakim Weatherspoon']
Unshackle the cloud