• Title, Summary, Keyword: High Availability

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High Availability Web Server Cluster Using Self-healing Technique (자가 치유 기법을 이용한 고가용도 웹 서버 클러스터)

  • Chung, Ji Yung;Kim, Young Ro
    • Journal of the Korea Society of Digital Industry and Information Management
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    • v.5 no.1
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    • pp.23-32
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    • 2009
  • Although the web is becoming a widely accepted medium, it provides relatively poor performance and low availability. A cluster consists of a collection of interconnected stand-alone computers working together and provides a high-availability solution in application area such as web services or information systems. Web server clusters require a high-availability service with a proactive and practical fault management. However, as the system complexity grows, it is not easy to meet the requirement. Therefore, web server clusters must have self-fault management capability for meeting high-availability requirement. In this paper, we propose high availability web server clusters using self-healing technique with a minimal human intervention. Our experimental results show that a proposed method can be used to improve the availability of web server clusters.

A Study on the High-availability Linux Server for Multimedia Tourism Information System (멀티미디어 관광정보시스템을 위한 고가용성 리눅스 서버에 관한 연구)

  • Bae, Jae-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.9B
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    • pp.818-825
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    • 2004
  • High availability means Service-technology that can provide any solution when occur a problem in relation to hardware, software, network etc. We are in the times that the network computing service are essential to our daily life. So the importance of the high availability is being higher and higher in this social change such as the arrival of information anger times, e-commerce the extension of multi-media service etc. In this thesis, I analyzed about High-availability Linux Server for Multimedia Tourism Information System, and I proposed an alternative plan which related with its result.

A Study on the Assessment Measures for Availability of Information Assets (정보 자산에 대한 가용성 평가 방안에 관한 연구)

  • Kim, MinSu;Lee, Byoungcheon
    • Convergence Security Journal
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    • v.20 no.2
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    • pp.53-58
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    • 2020
  • In this study, it suggests the High Availability (HA) implementation plan of building a continuous service infrastructure as a strategy ensuring availability, as the importance of availability securing corporate business continuity emerges in the knowledge and information society. However, if the reliability of the criticality assessment of information asset is not ensured, it requires assessment measures for availability that can be managed by mapping with service maintenance assessment items, which are availability criteria based on the asset criticality evaluated through the asset value matrix because it is difficult to maintain security in conjunction with the value of real assets. Therefore, this study suggests the assessment measures for availability of information assets.

High Availability and Load Balancing for Virtual Private Networks by Multiple Links (링크 다중화를 통한 가상 사설망의 고가용성 및 부하 분산 기법)

  • Kwon, Jin-Baek
    • Convergence Security Journal
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    • v.8 no.4
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    • pp.51-56
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    • 2008
  • A combination of VPNs and dial-up access, such as DSL and Cable, usually provides the cost-effective solution as the substitution of private networks on high-cost leased line. The business demand for high availability has increased with VPN spreading. This paper presents the schemes for a high availability of network access and a load balancing of network traffic in VPN gateways by using multiple links or multihoming capability based on active-active approach. The high availability and load balancing of network links can be achieved by duplicating external network access into multiple independent links. This can provide a continuous network connection to internal users even if one of the links is failed. Moreover, it can provide twice network bandwidth by distributing the traffic into the links. Static and dynamic algorithms are proposed as the load balancing algorithms.

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A study on high availability of the linux clustering web server (리눅스 클러스터링 웹 서버의 고가용성에 대한 연구)

  • 박지현;이상문;홍태화;김학배
    • 제어로봇시스템학회:학술대회논문집
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    • pp.88-88
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    • 2000
  • As more and more critical commercial applications move on the Internet, providing highly available servers becomes increasingly important. One of the advantages of a clustered system is that it has hardware and software redundancy. High availability can be provided by detecting node or daemon failure and reconfiguring the system appropriately so that the workload can be taken over bi the remaining nodes in the cluster. This paper presents how to provide the guaranteeing high availability of clustering web server. The load balancer becomes a single failure point of the whole system. In order to prevent the failure of the load balancer, we setup a backup server using heartbeat, fake, mon, and checkpointing fault-tolerance method. For high availability of file servers in the cluster, we setup coda file system. Coda is a advanced network fault-tolerance distributed file system.

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A PROPOSED HIGH AVAILABILITY ARCHITECTURE FOR COMS GROUND CONTROL SYSTEM

  • Kim In-Jun;Kim Jae-Hoon
    • Bulletin of the Korean Space Science Society
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    • pp.266-269
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    • 2004
  • A satellite ground control system (SGCS) which monitors and controls a geostationary satellite 24 hours a day has to achieve the system architecture assuring high-level availability and redundancy scheme. The SGCS for Communication, Ocean, and Meteorological Satellite (COMS) is currently being developed in Korea, which will be implemented to satisfy high availability (HA), expansibility, and compatibility in design. In order to implement the system architecture to meet these characteristics, the SGCS for COMS introduces the concept of the real-time distributed system structure based on redundancy scheme for high availability, data replication and sharing, and CORBA middleware.

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Availability Improvement Model of (n,k) Cluster Systems using Software Rejuvenation (소프트웨어 재활기법을 적용한 (n,k) 클러스터 시스템의 가용도 향상 모델)

  • 이재성;박기진;강창훈;박범주;김성수
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.5_6
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    • pp.290-298
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    • 2003
  • Internet-based computer systems have to provide both high-availability and high-performance. Cluster technology has been used to obtain availability and performance simultaneously Generally, high-availability cluster systems tolerate a failure of a cluster node and cost-effectively solve it. In this paper, we study availability and downtime cost of (n,k) cluster systems. By considering performance, we model state transition of (n,k) cluster systems and apply software rejuvenation technique to improve availability of the system. We find that software rejuvenation can be used to improve availability of (n,k) cluster systems.

Implementation of data synchronization for local disks in Linux high availability system (리눅스 고가용 시스템에서 로컬 디스크 간 데이터 동기화 구현)

  • Park, seong-jong;Lee, cheol-hoo
    • Proceedings of the Korea Contents Association Conference
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    • pp.547-550
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    • 2008
  • Recently, changes in the environment of user-centric internet service such as blog, UCC and IPTV and ubiquitous computing based on web service are needed to high availability system platform. High availability system is to provide safe service continuously even if system failure occurs in clustering system at the network. And it is necessary to synchronize data for reliable service in high availability system. In this paper, I implement DRBD(Disk Replicated Block Device) which is synchronization technique for data of local disks in high availability system.

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A Study on the Architecture-based Model of High Availability of Railway Control Systems (열차제어시스템의 아키텍처 기반 고가용도 모델 적용에 관한 연구)

  • Lee, Kyoung-Haing;Kwon, Yong-Soo
    • Journal of the Korean Society for Railway
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    • v.14 no.2
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    • pp.87-93
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    • 2011
  • This work describes an availability model of highly available systems to achieve Five-9's availability. Modern railway systems have raised users' expectations of powerful "always on" services. The crucial characteristics of these highly available services are essential to many modern businesses area, such as telecommunications, railway systems, information operations, Web-based businesses, and so on. The architecture-based model of system availability is useful to assess the feasibility of meeting a high availability target. The Markov model approach is straightforward for relative system engineers to adapt when they model highly available system failure and the failure recovery process. This work proposed the improved availability model through UML2.0. It is shown that the architecture-based model of system availability is a good reasonable by its application of the railway systems.

The Effect of Educational Service Quality on Educational Satisfaction and Job Availability: Focused on Foodservice related Contract Department Students (교육서비스품질이 교육만족도와 직무유용성에 미치는 영향: 외식조리 관련 계약학과 학생을 중심으로)

  • Seo, Jae-Won
    • Culinary science and hospitality research
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    • v.23 no.4
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    • pp.203-215
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    • 2017
  • The purpose of this study is to investigate the effect of educational service quality on educational satisfaction and job usability. The results of the analysis are as follows. First, based on the theoretical background, factor analysis and reliability analysis were conducted. Five factors of tangibility, responsibility, reactivity, assurance, and empathy were found in the educational service quality. In addition, it was confirmed that there was no problem as a single factor in educational satisfaction and job availability, and these factors showed high reliability and validity. Second, in the relationship between educational service quality and educational satisfaction, all five factors which education service quality factors were found to affect educational satisfaction. The higher the factor of educational service quality, the students will be able to increase their satisfaction with education, which was a degree of satisfaction with the education of contract department. Third, in the effects of educational service quality factors on job availability, tangibility, responsibility, reactivity, and assurance have no effect and empathy affects job availability. In this study, although the factors of education service quality is high except empathy, it is not possible to increase the job availability that leads to successful business results. Fourth, job availability affects educational satisfaction. Therefore, the higher the level of job availability, educational satisfaction will also increase. The following are implications of this study. First, high-quality lectures, hands-on training, and educational programs are needed and values that students pursue must continuously increase. Second, there is a need for measures to improve job availability such as the formation of curriculum related to jobs and the demand for the training courses of restaurants.