171,317 research outputs found
Optimised auto-scaling for cloud-based web service
University of Technology Sydney. Faculty of Engineering and Information Technology.Elasticity and cost-effectiveness are two key features for ensuring that cloud-based web services appeal to more businesses. However, true elasticity and cost-effectiveness in the pay-per-use cloud business model has not yet been fully achieved. The explosion of cloud-based web services brings new challenges to enable the automatic scaling up and down of service provision when the workload is time-varying.
This research studies the problems associated with these challenges. It proposes a novel scheme to achieve optimised auto-scaling for cloud-based web services from three levels of cloud structure: Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). At the various levels, auto-scaling for cloud-based web services has different problems and requires different solutions.
At the SaaS level, this study investigates how to design and develop scalable web services, especially for time-consuming applications. To achieve the greatest efficiency, the optimisation of service provision problem is studied by providing the minimum functionality and fastest scalability performance concerning the speed-up curve and QoS (Quality of Service) of the SLA (Service-Level Agreement). At the PaaS level, this work studies how to support dynamic re-configuration when workloads change and the effective deployment of various kinds of web services to the cloud. To achieve optimised auto-scaling of this deployment, a platform is designed to deploy all web services automatically with the minimal number of cloud resources by satisfying the QoS of SLAs. At the IaaS level for two infrastructure resources of virtual machine (VM) and virtual network (VN), this research focuses on studying two types of cloud-based web service: computation-intensive and bandwidth-intensive. To address the optimised auto-scaling problem for computation-intensive cloud-based web service, data-driven VM auto-scaling approaches are proposed to handle the workload in both stable and dynamic environments. To address the optimised auto-scaling problem for bandwidth-intensive cloud-based web service, this study proposes a novel approach to predict the volume of requests and dynamically adjust the software defined network (SDN)-based network configuration in the cloud to auto-scale the service with minimal cost.
This research proposes comprehensive and profound perspectives to solve the auto-scaling optimisation problems for cloud-based web services. The proposed approaches not only enable cloud-based web services to minimise resource consumption while auto-scaling service provision to achieve satisfying performance, but also save energy consumption for the global realisation of green computing. The performance of the proposed approaches has been evaluated on a public platform (e.g. Amazon EC2) with the real dataset workload of web services. The experiment results demonstrate that the proposed approaches are practicable and achieve superior performance to other benchmark methods
Blockchain-Enabled DPKI Framework
Public Key Infrastructures (PKIs), which rely on digital signature technology and establishment
of trust and security association parameters between entities, allow entities
to interoperate with authentication proofs, using standardized digital certificates (with
X.509v3 as the current reference). Despite PKI technology being used by many applications
for their security foundations (e.g. WEB/HTTPS/TLS, Cloud-Enabled Services,
LANs/WLANs Security, VPNs, IP-Security), there are several concerns regarding their
inherent design assumptions based on a centralized trust model.
To avoid some problems and drawbacks that emerged from the centralization assumptions,
a Decentralized Public Key Infrastructure (DPKI), is an alternative approach. The
main idea for DPKIs is the ability to establish trust relations between all parties, in a
web-of-trust model, avoiding centralized authorities and related root-of-trust certificates.
As a possible solution for DPKI frameworks, the Blockchain technology, as an enabler
solution, can help overcome some of the identified PKI problems and security drawbacks.
Blockchain-enabled DPKIs can be designed to address a fully decentralized ledger for
managed certificates, providing data-replication with strong consistency guarantees, and
fairly distributed trust management properties founded on a P2P trust model. In this
approach, typical PKI functions are supported cooperatively, with validity agreement
based on consistency criteria, for issuing, verification and revocation of X509v3 certificates.
It is also possible to address mechanisms to provide rapid reaction of principals in
the verification of traceable, shared and immutable history logs of state-changes related
to the life-cycle of certificates, with certificate validation rules established consistently by
programmable Smart Contracts executed by peers.
In this dissertation we designed, implemented and evaluated a Blockchain-Enabled
Decentralized Public Key Infrastructure (DPKI) framework, providing an implementation
prototype solution that can be used and to support experimental research. The
proposal is based on a framework instantiating a permissioned collaborative consortium
model, using the service planes supported in an extended Blockchain platform leveraged
by the Hyperledger Fabric (HLF) solution. In our proposed DPKI framework model,
X509v3 certificates are issued and managed following security invariants, processing
rules, managing trust assumptions and establishing consistency metrics, defined and executed in a decentralized way by the Blockchain nodes, using Smart Contracts. Certificates
are issued cooperatively and can be issued with group-oriented threshold-based
Byzantine fault-tolerant (BFT) signatures, as group-oriented authentication proofs. The
Smart Contracts dictate how Blockchain peers participate consistently in issuing, signing,
attestation, validation and revocation processes. Any peer can validate certificates
obtaining their consistent states consolidated in closed blocks in a Meckle tree structure
maintained in the Blockchain. State-transition operations are managed with serializability
guarantees, provided by Byzantine Fault Tolerant (BFT) consensus primitives
Technical Report on Deploying a highly secured OpenStack Cloud Infrastructure using BradStack as a Case Study
Cloud computing has emerged as a popular paradigm and an attractive model for
providing a reliable distributed computing model.it is increasing attracting
huge attention both in academic research and industrial initiatives. Cloud
deployments are paramount for institution and organizations of all scales. The
availability of a flexible, free open source cloud platform designed with no
propriety software and the ability of its integration with legacy systems and
third-party applications are fundamental. Open stack is a free and opensource
software released under the terms of Apache license with a fragmented and
distributed architecture making it highly flexible. This project was initiated
and aimed at designing a secured cloud infrastructure called BradStack, which
is built on OpenStack in the Computing Laboratory at the University of
Bradford. In this report, we present and discuss the steps required in
deploying a secured BradStack Multi-node cloud infrastructure and conducting
Penetration testing on OpenStack Services to validate the effectiveness of the
security controls on the BradStack platform. This report serves as a practical
guideline, focusing on security and practical infrastructure related issues. It
also serves as a reference for institutions looking at the possibilities of
implementing a secured cloud solution.Comment: 38 pages, 19 figures
High-Performance Cloud Computing: A View of Scientific Applications
Scientific computing often requires the availability of a massive number of
computers for performing large scale experiments. Traditionally, these needs
have been addressed by using high-performance computing solutions and installed
facilities such as clusters and super computers, which are difficult to setup,
maintain, and operate. Cloud computing provides scientists with a completely
new model of utilizing the computing infrastructure. Compute resources, storage
resources, as well as applications, can be dynamically provisioned (and
integrated within the existing infrastructure) on a pay per use basis. These
resources can be released when they are no more needed. Such services are often
offered within the context of a Service Level Agreement (SLA), which ensure the
desired Quality of Service (QoS). Aneka, an enterprise Cloud computing
solution, harnesses the power of compute resources by relying on private and
public Clouds and delivers to users the desired QoS. Its flexible and service
based infrastructure supports multiple programming paradigms that make Aneka
address a variety of different scenarios: from finance applications to
computational science. As examples of scientific computing in the Cloud, we
present a preliminary case study on using Aneka for the classification of gene
expression data and the execution of fMRI brain imaging workflow.Comment: 13 pages, 9 figures, conference pape
Cloudbus Toolkit for Market-Oriented Cloud Computing
This keynote paper: (1) presents the 21st century vision of computing and
identifies various IT paradigms promising to deliver computing as a utility;
(2) defines the architecture for creating market-oriented Clouds and computing
atmosphere by leveraging technologies such as virtual machines; (3) provides
thoughts on market-based resource management strategies that encompass both
customer-driven service management and computational risk management to sustain
SLA-oriented resource allocation; (4) presents the work carried out as part of
our new Cloud Computing initiative, called Cloudbus: (i) Aneka, a Platform as a
Service software system containing SDK (Software Development Kit) for
construction of Cloud applications and deployment on private or public Clouds,
in addition to supporting market-oriented resource management; (ii)
internetworking of Clouds for dynamic creation of federated computing
environments for scaling of elastic applications; (iii) creation of 3rd party
Cloud brokering services for building content delivery networks and e-Science
applications and their deployment on capabilities of IaaS providers such as
Amazon along with Grid mashups; (iv) CloudSim supporting modelling and
simulation of Clouds for performance studies; (v) Energy Efficient Resource
Allocation Mechanisms and Techniques for creation and management of Green
Clouds; and (vi) pathways for future research.Comment: 21 pages, 6 figures, 2 tables, Conference pape
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