Eric Deliot

A framework for coordinated multi-modal browsing with multiple clients

As users acquire or gain access to an increasingly diverse range of web access clients, web applications are adapting their user interfaces to support multiple modalities on multiple client types. User experiences can be enhanced by clients with differing capabilities combining to provide a distributed user interface to applications. Indeed, users will be frustrated if their interaction with applications is limited to one client at a time.This paper discusses the requirements for coordinating web interaction across an aggregation of clients. We present a framework for multi-device browsing that provides both coordinated navigation between web resources and coordinated interaction between variants, or representations, of those resources once instantiated in the clients. The framework protects the application from some of the complexities of client aggregation.We show how a small number of enhancements to the XForms and XML Events vocabularies can facilitate coordination between clients and provide an appropriate level of control to applications. We also describe a novel proxy which consolidates HTTP requests from aggregations of clients and reduces the burden that multi-client browsing places on the application.

Breaking open the set top box

In this paper we describe the work being done at HP Labs Bristol in the area of home networks and gateways. This work is based on the idea of breaking open the set top box by physically separating the access network specific functions from the application specific functions. The access network specific functions reside in an access network gateway that can be shared by many end user devices. The first section of the paper present the philosophy behind this approach. The end user devices and the access network gateways must be interconnected by a high bandwidth network which can offer a bounded delay service for delay sensitive traffic. We are advocating the use of IEEE 1394 for this network, and the next section of the paper gives a brief introduction to this technology. We then describe a prototype digital video broadcasting satellite compliant gateway that we have built. This gateway could be used, for example, by a PC for receiving a data service or by a digital TV for receiving an MPEG-2 video service. A control architecture is the presented which uses a PC application to provide a web based user interface to the system. Finally, we provide details of our work on extending the reach of IEEE 1394 and its standardization status.

CLON: Overlay Networks and Gossip Protocols for Cloud Environments

Although epidemic or gossip-based multicast is a robust and scalable approach to reliable data dissemination, its inherent redundancy results in high resource consumption on both links and nodes. This problem is aggravated in settings that have costlier or resource constrained links as happens in Cloud Computing infrastructures composed by several interconnected data centers across the globe. The goal of this work is therefore to improve the efficiency of gossip-based reliable multicast by reducing the load imposed on those constrained links. In detail, the proposed clon protocol combines an overlay that gives preference to local links and a dissemination strategy that takes into account locality. Extensive experimental evaluation using a very large number of simulated nodes shows that this results in a reduction of traffic in constrained links by an order of magnitude, while at the same time preserving the resilience properties that make gossip-based protocols so attractive.

High-speed Storage Nodes for the Cloud

In this paper, we describe an architecture for high-speed storage nodes intended for supporting cloud-based storage I/O intensive applications such as file servers, backup servers and databases. The nodes can host multiple virtual machines each having direct access to a storage array via Single Route I/O Virtualization (SR-IOV). This is done in a way which does not compromise security. We demonstrate that SR-IOV imposes negligible overhead for storage I/O and provides the hosted virtual machines with four times the storage I/O bandwidth than is available from the same hardware when I/O is redirected through the hyper visor. We describe how the storage nodes are incorporated into a heterogeneous Infrastructure as a Service (IaaS) consisting of mixed storage and compute nodes.

Cells: A Self-Hosting Virtual Infrastructure Service

We describe the design and implementation of Cells, a novel multi-tenanted virtual infrastructure service. Cells has the unique property of being self-hosting: it operates its own management system within one of the tenant virtual infrastructures that it manages and therefore benefits from the same security, flexibility and scalability as other tenant services. Cells is also differentiated by its declarative interface for infrastructure configuration, and its fine-grained control of network and storage connections within and between tenant infrastructures.

Loom: Complex large-scale visual insight for large hybrid IT infrastructure management

Abstract Interactive visual exploration techniques (IVET) such as those advocated by Shneiderman and extreme scale visual analytics have successfully increased our understanding of a variety of domains that produce huge amounts of complex data. In spite of their complexity, IT infrastructures have not benefited from the application of IVET techniques. Loom is inspired in IVET techniques and builds on them to tame increasing complexity in IT infrastructure management systems guaranteeing interactive response times and integrating key elements for IT management: Relationships between managed entities coming from different IT management subsystems, alerts and actions (or reconfigurations) of the IT setup. The Loom system builds on two main pillars: (1) a multiplex graph spanning data from different ITIMs; and (2) a novel visualisation arrangement: the Loom “Thread” visualisation model. We have tested this in a number of real-world applications, showing that Loom can handle million of entities without losing information, with minimum context switching, and offering better performance than other relational/graph-based systems. This ensures interactive response times (few seconds as 90th percentile). The value of the “Thread” visualisation model is shown in a qualitative analysis of users’ experiences with Loom.