459,806 research outputs found
Performing Under Pressure: IT Execution in a $1.4bn Business Transformation
This teaching case provides a practical illustration of the challenges in executing large-scale ITbased
change. It describes how the Commonwealth Bank of Australia replaced its service and
sales systems between 2003 and 2006 with the goal of collating a “single view of client”. The
case is an exemplar of staged incremental development. The sponsor set up multiple work streams
and ran them as independently as possible. Regular releases delivered incremental change to the
business, incorporated lessons learned, and added further functionality. This had implications for
architecture, software development, training, testing, and risk management. There were
significant change management challenges.
The case provides students with insights into program management in IT transformations,
architecture, project management, software delivery lifecycles, risk management, logistics and IT
infrastructure
A peer-to-peer service architecture for the Smart Grid
Short paperThe Smart Grid vision needs to address hard challenges such as interoperability, reliability and scalability before it can become fulfilled. The need to provide full interoperability between current and future energy and non-energy systems and its disparate technologies along with the problem of seamless discovery, configuration, and communication of a large variety of networked devices ranging from the resource constrained sensing devices to the large machines inside a data center requires an agnostic Service Oriented Architecture. Moreover, the sheer scale of the Smart Grid and the criticality of the communication among its subsystems for proper management, demands a scalable and reliable communication framework able to work in an heterogeneous and dynamic environment. In this position paper, we propose a generic framework, based on Web Services for interoperability, and epidemic or gossip based communication protocols for reliability and scalability, that can serve a general management substrate where several Smart Grid problems can be solved. We illustrate the flexibility of the proposed framework by showing how it can be used in two specific scenarios.Important challenges in interoperability, reliability, and scalability need to be addressed before the Smart Grid vision can be fulfilled. The sheer scale of the electric grid and the criticality of the communication among its subsystems for proper management, demands a scalable and reliable communication framework able to work in an heterogeneous and dynamic environment. Moreover, the need to provide full interoperability between diverse current and future energy and non-energy systems, along with seamless discovery and configuration of a large variety of networked devices, ranging from the resource constrained sensing devices to servers in data centers, requires an implementation-agnostic Service Oriented Architecture. In this position paper we propose that this challenge can be addressed with a generic framework that reconciles the reliability and scalability of Peer-to-Peer systems, with the industrial standard interoperability of Web Services. We illustrate the flexibility of the proposed framework by showing how it can be used in two specific scenarios
An experimental dynamic RAM video cache
As technological advances continue to be made, the demand for more efficient distributed multimedia systems is also affirmed. Current support for end-to-end QoS is still limited; consequently mechanisms are required to provide flexibility in resource loading. One such mechanism, caching, may be introduced both in the end-system and network to facilitate intelligent load balancing and resource management. We introduce new work at Lancaster University investigating the use of transparent network caches for MPEG-2. A novel architecture is proposed, based on router-oriented caching and the employment of large scale dynamic RAM as the sole caching medium. The architecture also proposes the use of the ISO/IEC standardised DSM-CC protocol as a basic control infrastructure and the caching of pre-built transport packets (UDP/IP) in the data plane. Finally, the work discussed is in its infancy and consequently focuses upon the design and implementation of the caching architecture rather than an investigation into performance gains, which we intend to make in a continuation of the work
Flexible Session Management in a Distributed Environment
Many secure communication libraries used by distributed systems, such as SSL,
TLS, and Kerberos, fail to make a clear distinction between the authentication,
session, and communication layers. In this paper we introduce CEDAR, the secure
communication library used by the Condor High Throughput Computing software,
and present the advantages to a distributed computing system resulting from
CEDAR's separation of these layers. Regardless of the authentication method
used, CEDAR establishes a secure session key, which has the flexibility to be
used for multiple capabilities. We demonstrate how a layered approach to
security sessions can avoid round-trips and latency inherent in network
authentication. The creation of a distinct session management layer allows for
optimizations to improve scalability by way of delegating sessions to other
components in the system. This session delegation creates a chain of trust that
reduces the overhead of establishing secure connections and enables centralized
enforcement of system-wide security policies. Additionally, secure channels
based upon UDP datagrams are often overlooked by existing libraries; we show
how CEDAR's structure accommodates this as well. As an example of the utility
of this work, we show how the use of delegated security sessions and other
techniques inherent in CEDAR's architecture enables US CMS to meet their
scalability requirements in deploying Condor over large-scale, wide-area grid
systems
Handling Policy Conflicts in Call Control
Policies are becoming increasingly important in modern computer systems as a mechanism for end users and organisations to exhibit a level of control over software. Policies have long been established as an effective mechanism for enabling appropriate access control over resources, and for enforcing security considerations. However they are now becoming valued as a more general management mechanism for large-scale heterogeneous systems, including those exhibiting adaptive or autonomic behaviour. In the telecommunications domain, features have been widely used to provide users with (limited) control over calls. However, features have the disadvantage that they are low-level and implementation-oriented in nature. Furthermore, apart from limited parameterisation of some features, they tend to be very inflexible. Policies, in contrast, have the potential to be much higher-level, goaloriented, and very flexible. This paper presents an architecture and its realisation for distributed and hierarchical policies within the telecommunications domain. The work deals with the important issue of policy conflict – the analogy of feature interaction
Accelerating Pattern Matching in Neuromorphic Text Recognition System Using Intel Xeon Phi Coprocessor
Neuromorphic computing systems refer to the computing architecture inspired by the working mechanism of human brains. The rapidly reducing cost and increasing performance of state-of-the-art computing hardware allows large-scale implementation of machine intelligence models with neuromorphic architectures and opens the opportunity for new applications. One such computing hardware is Intel Xeon Phi coprocessor, which delivers over a TeraFLOP of computing power with 61 integrated processing cores. How to efficiently harness such computing power to achieve real time decision and cognition is one of the key design considerations. This work presents an optimized implementation of Brain-State-in-a-Box (BSB) neural network model on the Xeon Phi coprocessor for pattern matching in the context of intelligent text recognition of noisy document images. From a scalability standpoint on a High Performance Computing (HPC) platform we show that efficient workload partitioning and resource management can double the performance of this many-core architecture for neuromorphic applications
Enterprise knowledge management: introducing new technologies in traditional Information Systems
Knowledge management systems described in research papers are rarely seen implemented in business realities, at least on a large scale. Companies are often tied to existing systems and cannot or would not revolutionize the situation to accommodate completely new solutions. Given this assumption, this work investigates several small-scale modifications that could be applied to in-place Information Systems so as to improve them with new technologies without major transformations and service discontinuities. The focus is interoperability, with a particular stress on the promotion of the ebXML registry standard. A universal interface for document management was defined, and the conforming “interoperable” DMSs were arranged within an architecture explicitly designed for ebXML-compliant access. This allowed standards-based manipulation of legacy DM systems. The closely related topic of Semantic knowledge management was also tackled. We developed Semantic tools integration for traditional repositories with low architectural impact. Finally, we discussed a novel issue in document categorization, and a new kind of ontology that could be used in that contex
A self-integration testbed for decentralized socio-technical systems
The Internet of Things (IoT) comes along with new challenges for experimenting, testing, and operating decentralized socio-technical systems at large-scale. In such systems, autonomous agents interact locally with their users, and remotely with other agents to make intelligent collective choices. Via these interactions they self-regulate the consumption and production of distributed (common) resources, e.g., self-management of traffic flows and power demand in Smart Cities. While such complex systems are often deployed and operated using centralized computing infrastructures, the socio-technical nature of these decentralized systems requires new value-sensitive design paradigms; empowering trust, transparency, and alignment with citizens’ social values, such as privacy preservation, autonomy, and fairness among citizens’ choices. Currently, instruments and tools to study such systems and guide the prototyping process from simulation, to live deployment, and ultimately to a robust operation of a high Technology Readiness Level (TRL) are missing, or not practical in this distributed socio-technical context. This paper bridges this gap by introducing a novel testbed architecture for decentralized socio-technical systems running on IoT. This new architecture is designed for a seamless reusability of (i) application-independent decentralized services by an IoT application, and (ii) different IoT applications by the same decentralized service. This dual self-integration promises IoT applications that are simpler to prototype, and can interoperate with decentralized services during runtime to self-integrate more complex functionality, e.g., data analytics, distributed artificial intelligence. Additionally, such integration provides stronger validation of IoT applications, and improves resource utilization, as computational resources are shared, thus cutting down deployment and operational costs. Pressure and crash tests during continuous operations of several weeks, with more than 80K network joining and leaving of agents, 2.4M parameter changes, and 100M communicated messages, confirm the robustness and practicality of the testbed architecture. This work promises new pathways for managing the prototyping and deployment complexity of decentralized socio-technical systems running on IoT, whose complexity has so far hindered the adoption of value-sensitive self-management approaches in Smart Cities
Self-management for large-scale distributed systems
Autonomic computing aims at making computing systems self-managing by using autonomic managers in order to reduce obstacles caused by management complexity. This thesis presents results of research on self-management for large-scale distributed systems. This research was motivated by the increasing complexity of computing systems and their management.
In the first part, we present our platform, called Niche, for programming self-managing component-based distributed applications. In our work on Niche, we have faced and addressed the following four challenges in achieving
self-management in a dynamic environment characterized by volatile resources and high churn: resource discovery, robust and efficient sensing and actuation, management bottleneck, and scale. We present results of our research
on addressing the above challenges. Niche implements the autonomic computing architecture, proposed by IBM, in a fully decentralized way. Niche supports a network-transparent view of the system architecture simplifying
the design of distributed self-management. Niche provides a concise and expressive API for self-management. The implementation of the platform relies on the scalability and robustness of structured overlay networks. We proceed
by presenting a methodology for designing the management part of a distributed self-managing application. We define design steps that include partitioning of management functions and orchestration of multiple autonomic
managers. In the second part, we discuss robustness of management and data consistency, which are necessary in a distributed system. Dealing with the effect of churn on management increases the complexity of the management logic
and thus makes its development time consuming and error prone. We propose the abstraction of Robust Management Elements, which are able to heal themselves under continuous churn. Our approach is based on replicating a
management element using finite state machine replication with a reconfigurable replica set. Our algorithm automates the reconfiguration (migration) of the replica set in order to tolerate continuous churn. For data consistency, we propose a majority-based distributed key-value store supporting multiple consistency levels that is based on a peer-to-peer network. The store enables the tradeoff between high availability and data consistency. Using majority allows avoiding potential drawbacks of a master-based consistency control, namely, a single-point of failure and a potential performance bottleneck. In the third part, we investigate self-management for Cloud-based storage systems with the focus on elasticity control using elements of control theory and machine learning. We have conducted research on a number of different designs of an elasticity controller, including a State-Space feedback controller and a controller that combines feedback and feedforward control. We describe our experience in designing an elasticity controller for a Cloud-based key-value store using state-space model that enables to trade-off performance for cost. We describe the steps in designing an elasticity controller. We continue by
presenting the design and evaluation of ElastMan, an elasticity controller for Cloud-based elastic key-value stores that combines feedforward and feedback control
The ALI Architecture Description Language
Architecture Description Languages (ADLs) have emerged over the past two decades as a means to abstract details of large-scale systems in order to enable better intellectual control over the complete systems. Recently, there has been an explosion in the number of ADLs created in the research community. However, industrial adoption of these ADLs has been rather limited. This has been attributed to various reasons, including the lack of support of some ADLs for: variability management, requirements traceability, architectural artefact reusability and multiple architectural views. To overcome these limitations, this paper is a report on ALI, an ADL that was designed to complement existing work by adding mechanisms to address the aforementioned limitations. The ALI design principles, concepts, notations and formal semantics are presented in this paper. The notation is illustrated using two distinct case studies, one from the information systems domain " an Asset Management System (AMS); and another from the embedded systems domain - a Wheel Brake System (WBS)
- …