With the ever-spreading user-base in cloud datacenters, it has become increasingly challenging to satisfy each user’s service demand. Resource requirements or service demands of cloud users are embedded in virtual machines (VM). Virtual machines are software extensions of physical machines such that a single physical machine can generate a number of virtual machines and hence, can service multi...

The context is datacenter congestion control. Traditional TCP transport stacks fare poorly in this environment, which has led to considerable interest in recent years in developing specialized transports that aim to deliver high bandwidth utilization at extremely low, microsecond-level packet latency. This is important for demanding datacenter applications such as cloud storage and near-realtim...

For many organizations it is difficult to determine the total costs caused by offering own services in the cloud as well as to compare them with the costs caused by an in-house datacenter. In practice, some models exist that support organizations in analyzing costs. However, these models are mostly static and do not consider the dynamics of cost development when using cloud computing. The purpo...

Large-scale datacenters are the key infrastructures of cloud computing. Inside a datacenter, a large number of servers are interconnected using a specific datacenter network to deliver the infrastructure as a service (IaaS) for tenants. To realize novel cloud applications like the network virtualization and network isolation among tenants, the principle of software-defined network (SDN) has bee...

Due to the evolving Cloud Computing paradigm, there is a prevailing concern that in the near future data center managers may be in short supply. Cloud computing, as a whole, is becoming more prevalent into today’s computing world. In fact, cloud computing has become so popular that some are now referring to data centers as “cloud centers”. How does this interest in cloud computing translate int...

Cloud environments should provide network performance isolation for co-located untrusted tenants in a virtualized datacenter. We present key properties that a performance isolation solution should satisfy, and present our progress on Gatekeeper, a system designed to meet these requirements. Experiments on our Xen-based implementation of Gatekeeper in a datacenter cluster demonstrate effective a...

Efficient provisioning of resources is a challenging problem in cloud computing environments due to its dynamic nature and the need for supporting heterogeneous applications with different performance requirements. Currently, cloud datacenter providers either do not offer any performance guarantee or prefer static VM allocation over dynamic, which lead to inefficient utilization of resources. E...

Web browsers ostensibly provide strong isolation for the client-side components of web applications. Unfortunately, this isolation is weak in practice; as browsers add increasingly rich APIs to please developers, these complex interfaces bloat the trusted computing base and erode cross-app isolation boundaries. We reenvision the web interface based on the notion of a pico-datacenter, the client...

A key aspect of framing cloud datacenters Service Level Agreements is the derivation of downtime probability distribution function of a set of provisioned servers over a service window. This is further complicated by the hierarchy of power, network and server domains within any datacenter. This hierarchy adds significant complexity in the estimation of transient distributions. The process of fa...

A key aspect of cloud computing is the promise of infinite, scalable resources, and that cloud services should scale up and down on demand. This thesis investigates methods for dynamic resource allocation and management of services in cloud datacenters, introducing new approaches as well as improvements to established technologies. Virtualization is a key technology for cloud computing as it al...