208 research outputs found
An Autonomic Cross-Platform Operating Environment for On-Demand Internet Computing
The Internet has evolved into a global and ubiquitous communication medium interconnecting powerful application servers, diverse desktop computers and mobile notebooks. Along with recent developments in computer technology, such as the convergence of computing and communication devices, the way how people use computers and the Internet has changed people´s working habits and has led to new application scenarios. On the one hand, pervasive computing, ubiquitous computing and nomadic computing become more and more important since different computing devices like PDAs and notebooks may be used concurrently and alternately, e.g. while the user is on the move. On the other hand, the ubiquitous availability and pervasive interconnection of computing systems have fostered various trends towards the dynamic utilization and spontaneous collaboration of available remote computing resources, which are addressed by approaches like utility computing, grid computing, cloud computing and public computing. From a general point of view, the common objective of this development is the use of Internet applications on demand, i.e. applications that are not installed in advance by a platform administrator but are dynamically deployed and run as they are requested by the application user. The heterogeneous and unmanaged nature of the Internet represents a major challenge for the on demand use of custom Internet applications across heterogeneous hardware platforms, operating systems and network environments. Promising remedies are autonomic computing systems that are supposed to maintain themselves without particular user or application intervention. In this thesis, an Autonomic Cross-Platform Operating Environment (ACOE) is presented that supports On Demand Internet Computing (ODIC), such as dynamic application composition and ad hoc execution migration. The approach is based on an integration middleware called crossware that does not replace existing middleware but operates as a self-managing mediator between diverse application requirements and heterogeneous platform configurations. A Java implementation of the Crossware Development Kit (XDK) is presented, followed by the description of the On Demand Internet Computing System (ODIX). The feasibility of the approach is shown by the implementation of an Internet Application Workbench, an Internet Application Factory and an Internet Peer Federation. They illustrate the use of ODIX to support local, remote and distributed ODIC, respectively. Finally, the suitability of the approach is discussed with respect to the support of ODIC
Extending an open source enterprise service bus for multi-tenancy support focusing on administration and management
As part of cloud computing, the service model Platform-as-a-Service (PaaS) has emerged, where customers can develop and host internet-scale applications on cloud infrastructure. The Enterprise Service Bus (ESB) is one possible building block of a PaaS offering, providing integration capabilities for service-oriented architectures. Bringing the ESB to the cloud requires scalability and multi-tenancy support. When applied, these characteristics lead to economies of scale, reducing the costs per customer.
In this diploma thesis we specify, design, and implement a multi-tenant management application for an existing open source ESB. The management application grants tenant users limited configuration access to the ESB’s connectivity and integration services. A tenant registry and a service registry serve as platform-wide databases. We ensure data isolation between tenants for the management application and ESB message flows. Furthermore, the management application can control clusters of ESB instances, retaining elasticity. These goals also involve extensions to the ESB itself, which implements the Java Business Integration (JBI) specification. As a result, an integration scenario emerged from the EU-funded project 4CaaSt was applied to the system
NetServ Framework Design and Implementation 1.0
Eyeball ISPs today are under-utilizing an important asset: edge routers. We present NetServ, a programmable node architecture aimed at turning edge routers into distributed service hosting platforms. This allows ISPs to allocate router resources to content publishers and application service pro\-vi\-ders motivated to deploy content and services at the network edge. This model provides important benefits over currently available solutions like CDN. Content and services can be brought closer to end users by dynamically installing and removing custom modules as needed throughout the network. Unlike previous programmable router proposals which focused on customizing features of a router, NetServ focuses on deploying content and services. All our design decisions reflect this change in focus. We set three main design goals: a wide-area deployment, a multi-user execution environment, and a clear economic benefit. We built a prototype using Linux, NSIS signaling, and the Java OSGi framework. We also implemented four prototype applications: ActiveCDN provides publisher-specific content distribution and processing; KeepAlive Responder and Media Relay reduce the infrastructure needs of telephony providers; and Overload Control makes it possible to deploy more flexible algorithms to handle excessive traffic
Approach and realization of a multi-tenant service composition engine
The support of multi-tenancy is an essential requirement to leverage the full extent of Cloud computing. Multi-tenancy enables service providers to maximize the utilization of their infrastructure and to reduce the servicing costs per customer. With regard to the fact that nowadays new applications or services are often composed out of multiple existing services or applications, a middleware is required which enables these compositions. A Service Composition Engine (SCE) provides the required functionality to enable the definition and execution of service compositions.
In this diploma thesis we investigate the requirements and define an abstract architecture for the realization of a multi-tenant SCE. This architecture is prototypically realized with an open-source SCE and integrated into an existing multi-tenant aware ESB. The resulting middleware provides configurability for service compositions, tenant-aware messaging and tenant-based administration and management of the SCE and the ESB
Equipment management trial : final report
Executive Summary
The Equipment Management (EM) trial was one of the practical initiatives conceived and
implemented by members of The Application Home Initiative (TAHI) to demonstrate the
feasibility of interoperability between white and brown goods, and other domestic equipment.
The trial ran from October 2002 to June 2005, over which period it achieved its core
objectives through the deployment in early 2005 of an integrated system in trials in 15
occupied homes. Prior to roll out into the field, the work was underpinned by soak testing,
validation, laboratory experiments, case studies, user questionnaires, simulations and other
research, conducted in a single demonstration home in Loughborough, as well as in
Universities in the East Midlands and Scotland.
Throughout its life, the trial faced significant membership changes, which had a far greater
impact than the technical issues that were tackled. Two blue chip companies withdrew at the
point of signing the collaborative agreement; another made a major change in strategic
direction half way through and withdrew the major portion of its backing; another corporate left
at this point, a second one later; one corporate was a late entrant; the technical leader made
a boardroom decision not to do the engineering work that it had promised; one company went
into liquidation; another went up for sale whilst others reorganised. The trial was conducted
against this backdrop of continual commercial change. Despite this difficult operating
environment, the trial met its objectives, although not entirely as envisaged initially – a tribute
to the determination of the trial’s membership, the strength of its formal governance and
management processes, and especially, the financial support of the dti.
The equipment on trial featured a central heating/hot water boiler, washing machine, security
system, gas alarm and utility meters, all connected to a home gateway, integrated functionally
and presented to the users via a single interface.
The trial met its principal objective to show that by connecting appliances to each other and to
a support system, benefits in remote condition monitoring, maintenance, appliance & home
controls optimisation and convenience to the customer & service supplier could be provided.
This is one of two main reports that form the trial output (the other, the Multi Home Trial
Report, is available to EM Trial members only as it contains commercially sensitive
information). A supporting library of documents is also available and is held in the virtual
office hosted by Loughborough University Centre for the Integrated Home Environment
Network Infrastructures for Highly Distributed Cloud-Computing
Software-Defined-Network (SDN) is emerging as a solid opportunity for the Network Service Providers (NSP) to reduce costs while at the same time providing better and/or new services. The possibility to flexibly manage and configure highly-available and scalable network services through data model abstractions and easy-to-consume APIs is attractive and the adoption of such technologies is gaining momentum. At the same time, NSPs are planning to innovate their infrastructures through a process of network softwarisation and programmability. The SDN paradigm aims at improving the design, configuration, maintenance and service provisioning agility of the network through a centralised software control. This can be easily achievable in local area networks, typical of data-centers, where the benefits of having programmable access to the entire network is not restricted by latency between the network devices and the SDN controller which is reasonably located in the same LAN of the data path nodes. In Wide Area Networks (WAN), instead, a centralised control plane limits the speed of responsiveness in reaction to time-constrained network events due to unavoidable latencies caused by physical distances. Moreover, an end-to-end control shall involve the participation of multiple, domain-specific, controllers: access devices, data-center fabrics and backbone networks have very different characteristics and their control-plane could hardly coexist in a single centralised entity, unless of very complex solutions which inevitably lead to software bugs, inconsistent states and performance issues.
In recent years, the idea to exploit SDN for WAN infrastructures to connect multiple sites together has spread in both the scientific community and the industry. The former has produced interesting results in terms of framework proposals, complexity and performance analysis for network resource allocation schemes and open-source proof of concept prototypes targeting SDN architectures spanning multiple technological and administrative domains. On the other hand, much of the work still remains confined to the academy mainly because based on pure Openflow prototype implementation, networks emulated on a single general-purpose machine or on simulations proving algorithms effectiveness.
The industry has made SDN a reality via closed-source systems, running on single administrative domain networks with little if no diversification of access and backbone devices.
In this dissertation we present our contributions to the design and the implementation of SDN architectures for the control plane of WAN infrastructures. In particular, we studied and prototyped two SDN platforms to build a programmable, intent-based, control-plane suitable for the today highly distributed cloud infrastructures. Our main contributions are: (i) an holistic and architectural description of a distributed SDN control-plane for end-end QoS provisioning; we compare the legacy IntServ RSVP protocol with a novel approach for prioritising application-sensitive flows via centralised vantage points. It is based on a peer-to-peer architecture and could so be suitable for the inter-authoritative domains scenario. (ii) An open-source platform based on a two-layer hierarchy of network controllers designed to provision end-to-end connectivity in real networks composed by heterogeneous devices and links within a single authoritative domain. This platform has been integrated in CORD, an open-source project whose goal is to bring data-center economics and cloud agility to the NSP central office infrastructures, combining NFV (Network Function Virtualization), SDN and the elasticity of commodity clouds. Our platform enables the provisioning of connectivity services between multiple CORD sites, up to the customer premises. Thus our system and software contributions in SDN has been combined with a NFV infrastructure for network service automation and orchestration
A Platform as a Service Framework for Ambient Assisted Living Services
The primary objective of Ambient Assisted Living (AAL) technology is to provide
aid and assistance to individuals, particularly the elderly, in maintaining their
independence and residing in their own homes and their known environment for
an extended duration. AAL technology is becoming increasingly important due to
the continuous decrease of birth-rate and increasing life expectancy, leading to a
shrinking proportion of younger population in developed countries. This research
proposes a cloud-based platform as a service (PaaS) for AAL that enables service
providers to deliver services without the need for the user to invest in expensive
technical equipment in advance, thus reducing high start-up costs. This hurdle, as
identified by both peer groups and service solution vendors, stands as a pivotal
challenge demanding resolution.
The PaaS for AAL focuses on adaptation and personalization, as user acceptance
of AAL services depends heavily on their situational needs. To provide customization,
the PaaS for AAL can dynamically adapt its functionality and presentation of
information based on the context of the environment or user, such as the medical
state of the user and the condition at home. To store and retrieve information
about the user, an ontology-backed database is implemented, and information
about the environment is provided through interoperability with existing smart
home appliances, directly attached sensors, and external web services.
One of the key concerns of potential AAL users according to a field test during
the research is privacy-related. A PaaS for AAL places regulatory demands on
protecting the user’s privacy and personal information. Consequently, another
part of this work focuses on the question of how general data sharing is possible
based on the respective context of the user while protecting their privacy: By
implementing monitoring, access control, and enforcement of privacy preserving
data access, the platform for AAL is further enhanced. The extension of the
introduced privacy policy language with context awareness is a significant step
towards providing more robust privacy protection in AAL use cases. With a
concluding evaluation survey, it can be shown that it allows for more granular
control over data access and ensures that sensitive user data is only accessible
when necessary and under appropriate conditions
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