• Title, Summary, Keyword: Server

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Design and Implementation of Fault-tolerant server for Shared File System in SAN environment (SAN 환경에서 공유파일시스템을 위한 Fault-tolerant server 구현)

  • Choi, Young-Han;Lee, Ju-Pyung;Lee, Chul;Park, Kyu-Ho
    • Proceedings of the IEEK Conference
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    • pp.231-234
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    • 2003
  • This paper designs and implements fault-tolerant server of meta server for shared filesystem (SANfs) in SAN environment. SANfs is the filesystem that many clients can share data in Network-attached storage in SAN environment and meta server is the server that processes file operation in SANfs. The focus of this paper is the implementation of fault-tolerant server of meta server in SANfs. In the event of a meta server, meta server failovers to a fault-tolerant server where its processing continues seamlessly. If meta server doesn't restore, fault-tolerant server searches reliable client and makes another fault-tolerant server and work as meta server. Heartbeat monitors meta server and shadow server and controls them.

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A study on incrementally expandable online game server architecture (서비스 단계별 확장 가능한 온라인 게임 서버 구조에 대한 연구)

  • Kim Jeong-Hoon
    • Journal of the Korea Computer Industry Society
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    • v.7 no.3
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    • pp.237-244
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    • 2006
  • The purpose of this study is to propose the online game server architecture which can expand as the number of users increases. In most online game servers, there is a server group composed of a login server, a cache server, a database server, a game server, and an NPC server, and when the number of users increases, an additional server group with the same structure is installed. The server architecture proposed in this study does not install a server group composed of a login server, a cache server, a database server, a game server, an NPC server, etc., but installs a game server only. When there is a need for the cache server and database server, the required servers will be additionally installed, thus reducing costs.

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A Study of a Server Selection Model for Selecting a Replicated Server based on Downstream Measurement in the Server-side

  • Kim, Seung-Hae;Lee, Won-Hyuk;Cho, Gi-Hwan
    • Journal of Information Processing Systems
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    • v.2 no.2
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    • pp.130-134
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    • 2006
  • In the distributed replicating server model, the provision of replicated services will improve the performance of the providing service and efficiency for clients. Efficiently composing the server selection algorithm decreases the retrieval time for replicated data. In this paper, we define the system model that selects and connects the replicated server that provides an optimal service using the server-side downstream measurement and propose a server selection algorithm.

Implementation of Shadow Server for Fault-tolerance in SAN-based Shared File System (SAN 기반 공유 파일 시스템에서 Fault-tolerance를 위한 Shadow Server 구현)

  • 최영한;김형천;홍순좌
    • Proceedings of the Korean Information Science Society Conference
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    • pp.661-663
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    • 2004
  • 본 논문에서는 SAN 기반 공유 파일 시스템인 SANfs의 fault-tolerance를 보장받기 위해 fault-tolerant server인 shadow server를 구현하였다 SANfs(1)는 SAN에서 Network-attached storage에 접근하는 여러 클라이언트가 서로의 데이터를 공유할 수 있도록 도와주는 파일시스템이다. SANfs에서 파일 관리를 위해 meta server를 두고 있으며, 이 서버에서 네트워크를 통해 접근하는 털러 클라이언트의 request를 관리한다. SAMfs에서는 meta server를 통해 중앙 집중식으로 파일시스템을 관리하고 있기에 meta server가 fault가 나게 되면 전체 시스템의 동작이 멈추게 되는 single point-of-failure의 문제가 생기게 된다. 본 논문에서는 meta server가 fault가 났을 경우에도 지속적으로 서비스를 할 수 있도록 shadow server를 두었으며. 이 서버가 meta server의 이상 시 그 기능을 대행하도록 하였다. 본 논문의 shadow server는 평상시에 meta server와 파일시스템의 metadata의 동기를 맞추고 있으며, 이 정보를 가지고 meta server로 그 기능을 전환하였을 때 서비스를 해 주도록 하고 있다. 상대 서버의 이상 유무의 판단은 heartbeat를 통해 이루어지고 있으며, meta server로의 failover는 heartbeat의 주기에 영향을 받음을 실험을 통해 알게 되었다.

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Rsearch in Server Striping policy for Parallel Video Server System (Parallel Video Server system을 위한 Server Striping 정책에 관한 연구)

  • 구태연;김길용
    • Proceedings of the Korean Information Science Society Conference
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    • pp.576-578
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    • 2000
  • 현재의 대부분의 VOD System에서는 Single Server System의 제약인 확장성과 안정적 서비스를 제공하기 위해 Multi-Server System을 사용하고 있다. Multiple Server에 Video Data를 Striping한 구조를 Parallel Video Server Architecture라 한다. 본 연구에서는 Parallel Video Server System 상에서 Data의 Striping Policy에 대해 고찰해보고 이때 발생하는 load balancing과 redundancy 문제의 해결책을 제시하였다. 또한 이를 실제 local Network 시스템에 적용하여 구현하였다.

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Simulated Dynamic C&C Server Based Activated Evidence Aggregation of Evasive Server-Side Polymorphic Mobile Malware on Android

  • Lee, Han Seong;Lee, Hyung-Woo
    • International journal of advanced smart convergence
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    • v.6 no.1
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    • pp.1-8
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    • 2017
  • Diverse types of malicious code such as evasive Server-side Polymorphic are developed and distributed in third party open markets. The suspicious new type of polymorphic malware has the ability to actively change and morph its internal data dynamically. As a result, it is very hard to detect this type of suspicious transaction as an evidence of Server-side polymorphic mobile malware because its C&C server was shut downed or an IP address of remote controlling C&C server was changed irregularly. Therefore, we implemented Simulated C&C Server to aggregate activated events perfectly from various Server-side polymorphic mobile malware. Using proposed Simulated C&C Server, we can proof completely and classify veiled server-side polymorphic malicious code more clearly.

Distributed Server Configuration Scheme for Internet Online Game (인터넷 온라인 게임을 위한 서버의 분산구성 기법)

  • Lee, Nam-Jae;Seo, Duck-Won;Kwak, Hoon-Sung
    • Journal of Korea Game Society
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    • v.1 no.1
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    • pp.31-36
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    • 2001
  • Generally, the internet online game systems are divided into two parts, clients and servers. The clients provide a connection with game server to each user and communicate between them. And, the server controls all clients by the game rules fairly and manages database systems to maintain the user information. In this paper, we propose a configuration method for internet online game servers using distributed scheme. To apply this method, we divide game server into three sub-level parts again. First part of game server is login server to establish the connection between communication server and clients. Second part is communication server to connect between clients and main game server during playing the game. And last part is DBMS that performs database independently. Our proposed scheme suggests that the game server operates very stable because of decreasing of processing load by distributed scheme. So, our proposed server configuration applies to similar online game easily.

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A Study on Secure Kerberos Authentication using Trusted Authority in Network Structure (네트웍 환경에서 안전한 Kerberos 인증 메커니즘에 관한 연구)

  • 신광철;정진욱
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.12 no.2
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    • pp.123-133
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    • 2002
  • In Network Environment, Kerberos certification mechanism to require Kerberos server in other area unconditionally belief. Also, Kerberos server in cooperation area must be share server of other area and secret key. To solve these two problems, this paper proposed safe security mechanism of doing to ably IETF CAT's PKINIT/PKCROSS a1gorithm with Public Key Infrastructure and use Directory System and service between realms do trust and prove each Kerberos trust center base. Also, Although Kerberos server of each area must be foreknowing each server's secret key and public key, Obtain through Trust center and acquire each area's public key and common symmetric key, Application server excluded process that must register key in Key Distribution Center.

An Implementation of a ATMARP Multiple Server on the LINUX (리눅스 상에서 ATMARP 다중서버 구현)

  • 서은미;박광로;장일순;조경록;유영갑
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.3B
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    • pp.399-407
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    • 2000
  • Recently, supporting ATM networks under LINUX operating systems environment has been actively studied. An ATMARP server in a conventional LINUX environment was designed under the ATMARP single-server to operate independently within a Local IP Subnet(LIS). In this paper, an ATMARP multi-server is introduced and implemented an ATMARP-server managing multiple LIS's on the LINUX-based IPOA. The ATMARP protocol processing functions and addition/deletion functions on management tables are required to implement the ATMARP multi-server. These functions can solve the problem of increasing the number of ATMARP servers in ATMARP single-server environment. The file transmission experiment with a connection configuration between LIS's shows that multiple LIS' con be managed by an ATMARP-server. As the results, the ATMARP multi-server scheme yields a smaller number of servers than that of the conventional ATMARP single-server scheme, and the network composition can be improved substantially.

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Impact Evaluation of DDoS Attacks on DNS Cache Server Using Queuing Model

  • Wang, Zheng;Tseng, Shian-Shyong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.4
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    • pp.895-909
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    • 2013
  • Distributed Denial-of-Service (DDoS) attacks towards name servers of the Domain Name System (DNS) have threaten to disrupt this critical service. This paper studies the vulnerability of the cache server to the flooding DNS query traffic. As the resolution service provided by cache server, the incoming DNS requests, even the massive attacking traffic, are maintained in the waiting queue. The sojourn of requests lasts until the corresponding responses are returned from the authoritative server or time out. The victim cache server is thus overloaded by the pounding traffic and thereafter goes down. The impact of such attacks is analyzed via the model of queuing process in both cache server and authoritative server. Some specific limits hold for this practical dual queuing process, such as the limited sojourn time in the queue of cache server and the independence of the two queuing processes. The analytical results are presented to evaluate the impact of DDoS attacks on cache server. Finally, numerical results are provided for further analysis.