scholarly journals Self-healing trans-cloud applications

Computing ◽  
2021 ◽  
Author(s):  
Antonio Brogi ◽  
Jose Carrasco ◽  
Francisco Durán ◽  
Ernesto Pimentel ◽  
Jacopo Soldani

AbstractTrans-cloud applications consist of multiple interacting components deployed across different cloud providers and at different service layers (IaaS and PaaS). In such complex deployment scenarios, fault handling and recovery need to deal with heterogeneous cloud offerings and to take into account inter-component dependencies. We propose a methodology for self-healing trans-cloud applications from failures occurring in application components or in the cloud services hosting them, both during deployment and while they are being operated. The proposed methodology enables reducing the time application components rely on faulted services, hence residing in “unstable” states where they can suddenly fail in cascade or exhibit erroneous behaviour. We also present an open-source prototype illustrating the feasibility of our proposal, which we have exploited to carry out an extensive evaluation based on controlled experiments and monkey testing.

2017 ◽  
Vol 26 (02) ◽  
pp. 1742003 ◽  
Author(s):  
Mohamed Mohamed ◽  
Obinna Anya ◽  
Samir Tata ◽  
Nagapramod Mandagere ◽  
Nathalie Baracaldo ◽  
...  

Cloud providers offer services at different levels of abstraction from infrastructure to applications. The quality of Cloud services is a key determinant of the overall service level a provider offers to its customers. Service Level Agreements (SLAs) are (1) crucial for Cloud customers to ensure that promised levels of services are met, (2) an important sales instrument and (3) a differentiating factor for providers. Cloud providers and services are often selected more dynamically than in traditional IT services, and as a result, SLAs need to be set up and their monitoring implemented to match the same speed. In this context, managing SLAs is complex: different Cloud providers expose different management interfaces and SLA metrics differ from one provider to another. In this paper, we will analyze how IT service quality has been defined and managed over time, discuss how to manage SLAs in today’s multi-layer, multi-sourced Cloud environments, and what to expect going forward. A particular focus will be made on the rSLA framework that enables fast setup of SLA monitoring in dynamic and heterogeneous Cloud environments. The rSLA framework is made up of three main components: the rSLA language to formally represent SLAs, the rSLA Service, which interprets the SLAs and implements the behavior specified in them, and a set of Xlets-lightweight, dynamically bound adapters to monitoring and controlling interfaces. rSLA has been tested in the context of a real pilot and found to reduce the client on-boarding process from months to weeks.


2012 ◽  
Vol 2 (1) ◽  
pp. 44-57 ◽  
Author(s):  
Yannis Siahos ◽  
Iasonas Papanagiotou ◽  
Alkis Georgopoulos ◽  
Fotis Tsamis ◽  
Ioannis Papaioannou

The authors present their experience and practices of introducing cloud services, as a means to simplify the adoption of ICT (Information Communication and Technology) in education, using Free/Open Source Software. The solution creates a hybrid cloud infrastructure, in order to provide a pre-installed (Ubuntu and Linux Terminal Server Project) virtual machine, acting as a server inside the school, providing desktop environment based on the Software as a Service cloud model, where legacy PCs act as stateless devices. Classroom management is accomplished using the application “Epoptes.” To minimize administration tasks, educational software is provided accordingly, either on-line or through repositories to automate software installation (including patches and updates). The advantages of the hybrid cloud implementation, include services that are not completely dependent on broadband connections’ state, minimal cost, reusability of obsolete equipment, ease of administration, centralized management, patches and educational software provisioning and, above all, facilitation of the educational procedure.


2015 ◽  
Vol 50 ◽  
pp. 38-48 ◽  
Author(s):  
Jen-Hsiang Chen ◽  
Fahmida Abedin ◽  
Kuo-Ming Chao ◽  
Nick Godwin ◽  
Yinsheng Li ◽  
...  

2021 ◽  
Author(s):  
Lucas Bragança ◽  
Jeronimo Penha ◽  
Michael Canesche ◽  
Dener Ribeiro ◽  
José Augusto M. Nacif ◽  
...  

FPGAs are suitable to speed up gene regulatory network (GRN) algorithms with high throughput and energy efficiency. In addition, virtualizing FPGA using hardware generators and cloud resources increases the computing ability to achieve on-demand accelerations across multiple users. Recently, Amazon AWS provides high-performance Cloud's FPGAs. This work proposes an open source accelerator generator for Boolean gene regulatory networks. The generator automatically creates all hardware and software pieces from a high-level GRN description. We evaluate the accelerator performance and cost for CPU, GPU, and Cloud FPGA implementations by considering six GRN models proposed in the literature. As a result, the FPGA accelerator is at least 12x faster than the best GPU accelerator. Furthermore, the FPGA reaches the best performance per dollar in cloud services, at least 5x better than the best GPU accelerator.


Author(s):  
Egbert de Smet

Whereas “Open Source” in software is still gaining momentum in many fields of applications, it is even more present in the “behind the curtains” scene of the Cloud. It is behind the scenes because Cloud tools are only operated by Cloud providers creating their infrastructure, not by end users. But as that infrastructure is going to be a crucial part of the IT environment of the future, like water and power supply have become for the wider living environments, it is good to note that this infrastructure is not limited to (commercial) proprietary technology and standards, but rather is subject to input from the major Open Source players. This chapter reviews the main technologies of this moment in Cloud software: CloudStack of Citrix and Apache, OpenStack of Suse and Openshift from RedHat. Also the CEPH-technology for distributed storage is added in this overview due to its obvious relevance for the Cloud. The brief review of these products confirms that FOSS indeed plays a major role in the Cloud, opening up that technology for open standards and “public” ownership of this soon-to-be an essential part of our IT environment.


Author(s):  
Sanjay P. Ahuja ◽  
Thomas F. Furman ◽  
Kerwin E. Roslie ◽  
Jared T. Wheeler

There are several public cloud providers that provide service across different cloud models such as IaaS, PaaS, and SaaS. End users require an objective means to assess the performance of the services being offered by the various cloud providers. Benchmarks have typically been used to evaluate the performance of various systems and can play a vital role in assessing performance of the different public cloud platforms in a vendor neutral manner. Amazon's EC2 Service is one of the leading public cloud service providers and offers many different levels of service. The research in this chapter focuses on system level benchmarks and looks into evaluating the memory, CPU, and I/O performance of two different tiers of hardware offered through Amazon's EC2. Using three distinct types of system benchmarks, the performance of the micro spot instance and the M1 small instance are measured and compared. In order to examine the performance and scalability of the hardware, the virtual machines are set up in a cluster formation ranging from two to eight nodes. The results show that the scalability of the cloud is achieved by increasing resources when applicable. This chapter also looks at the economic model and other cloud services offered by Amazon's EC2, Microsoft's Azure, and Google's App Engine.


Author(s):  
Ovunc Kocabas ◽  
Regina Gyampoh-Vidogah ◽  
Tolga Soyata

This chapter describes the concepts and cost models used for determining the cost of providing cloud services to mobile applications using different pricing models. Two recently implemented mobile-cloud applications are studied in terms of both the cost of providing such services by the cloud operator, and the cost of operating them by the cloud user. Computing resource requirements of both applications are identified and worksheets are presented to demonstrate how businesses can estimate the operational cost of implementing such real-time mobile cloud applications at a large scale, as well as how much cloud operators can profit from providing resources for these applications. In addition, the nature of available service level agreements (SLA) and the importance of quality of service (QoS) specifications within these SLAs are emphasized and explained for mobile cloud application deployment.


2015 ◽  
pp. 1464-1486
Author(s):  
Chengcheng Huang ◽  
Phil Smith ◽  
Zhaohao Sun

Securing a cloud network is an important challenge for delivering cloud services to enterprise clouds. There are a number of secure network protocols, such as VPN protocols, currently available, to provide different secure network solutions for enterprise clouds. For example, PPTP, IPSec, and SSL/TLS are the most widely used VPN protocols in today's securing network solutions. However, there are some significant challenges in the implementation stage. For example, which VPN solution is easy to deploy in delivering cloud services? Which VPN solution is most user-friendly in enterprise clouds? This chapter explores these issues by implementing different VPNs in a virtual cloud network environment using open source software and tools. This chapter also reviews cloud computing and cloud services and looks at their relationships. The results not only provide experimental evidence but also facilitate the network implementers in deployment of secure network solutions for enterprise cloud services.


Author(s):  
Djamel Benmerzoug

The challenges that Cloud computing poses to business processes integration, emphasize the need for addressing two major issues: (i) which integration approach should be used allowing an adequate description of interaction aspects of the composed software components ? (ii) how are these interaction descriptions stored and shared to allow other software artifacts to (re)use them ? To address these issues, in this paper the authors propose an Agent Interaction Protocols (AiP)-based approach for reusing and aggregating existing Cloud services to create a new desired business application. The proposed approach facilitates rapid development and provisioning of composite Cloud services by specifying what to compose as an AiP. Furthermore, the authors develop an agent-based architecture that supports flexible scaling of business processes in a virtualized Cloud computing environment. The main goal of the proposed architecture is to address and tackle interoperability challenges at the Cloud application level. It solves the interoperability issues between heterogeneous Cloud services environments by offering a harmonized API. Also, it enables the deployment of applications at public, private or hybrid multi-Cloud environments.


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