멀티미디어 저장 시스템을 위한 사용자 요청 통합

Unifying User Requests for Multimedia Storage Systems

  • 황인준 (아주대학교 통신전문대학원)
  • 발행 : 2002.02.01

초록

대부분의 멀티미디어 저장 시스템은 사용자의 요청을 라운드-로빈(round-robin) 방식으로 수행한다. 즉, 사용자는 일정한 간격을 두고 정해진 시간 동안 저장 시스템의 서비스를 받게 된다. 더욱이, 여기에 사용되는 대부분의 알고리즘들은 시스템과 밀접하게 연관된 비용함수를 바탕으로 평가를 받게 된다. 이러한 알고리즘의 FCFS, SCAN, SCAN-EDF 등이 있다. 본 논문에서는 주어진 사용자 요청에 대해서 사용자 대기 시간이나 최대 디스크 대역폭과 같은 제약 조건들을 만족시키는 동시에 임의의 비용 함수에 대해 최적의 스케줄인 통합 읽기 요청(Unified Read Request)을 생성하는 요청 통합기(Request Unifier) 모듈을 설계한다. 그리고 이러한 사용자 요청 통합에 사용될 수 있는 세 개의 알고리즘을 제안하고 성능 평가를 통해 그들의 장단점을 비교해 본다.

Most work on multimedia storage systems has assumed that client will be serviced using a round-robin strategy. The server services the clients in rounds and each client is allocated a time slice within that round. Furthermore, most such algorithms are evaluated on the basis of a tightly coupled cost function. This is the basis of well-known algorithm such as FCFS, SCAN, SCAN-EDF, etc. In this paper, we describe a scheduling module called Request Unifier(RU) that takes as input, a set of client request, and a set of constraints on the desired performance such as client waiting time or maximum disk bandwidth, and a cost function. It produces as output a Unified Read Request(URR), telling the storage server which data items to read and when these data items to be delivered to the clients. Given a cost function, a URR is optimal if there is no other URR satisfying the constraints with a lower cost. We present three algorithms in this paper that can accomplish this kind of request merging and compare their performance through an experimental evaluation.

키워드

참고문헌

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