An ORB Extension for support of Fault-Tolerant CORBA

고장감내 CORBA를 지원하기 위한 객체중개자의 확장

  • 신범주 (한국전자통신연구원 자료저장 S/W팀) ;
  • 손덕주 (한국전자통신연구원 인터넷서비스연구부) ;
  • 김명준 (한국전자통신연구원 컴퓨터소프트웨어기술연구소)
  • Published : 2001.04.01

Abstract

The failure of network and/or node on which server object is executed is a single point of system failure in the CORBA application. One of the possible ways to overcome such problem is to replicate server objects to several independent nodes. The replicated objects executing same tasks are called object group. In order to provide fault tolerance of server object, this paper proposes and implements new CORBA model that supports the object group based on active replication. The proposed model not only provides interoperability with existing CORBA application but also minimizes additional application interface required to support object group because it uses nop to exchange messages between client and server. And this paper extends IDL structure. Depending to application logic, it makes possible to prevent performance degradation caused by consistency maintenance. At present, this paper supports only active replication. But it can be easily extended to provide warm ancVor cold passive replication without modification of architecture required for active replication.

CORBA 응용에서는 서버 객체가 수행되는 노드 및 네트웍에 오류가 발생할 경우 전체 서비스가 중단되는 결과를 초래한다. 이 같은 문제를 해결하는 방법 중 하나는 동일한 서버 객체들을 여러 노드에 중복 수행시키는 것이다. 여러 노드에 중복되어 동일한 업무를 수행하는 객체들을 객체그룹이라 한다. 본 논문은 서버 객체의 고장감내를 지원하기 위하여 능동복제 방식의 객체그룹을 지원하는 고장감내 CORBA 모델을 제안하고 구현한 결과를 기술한다. 본 논문에서 제안하는 모델은 클라이언트와 서버 사이에 IIOP를 사용하기 때문에 기존의 CORBA 제품들과 상호 운용될 수 있을 분 아니라 추가되는 응용 프로그래밍 인터페이스를 최소화하는 장점을 제공한다. 또 응용의 특성에 따라 상태일치 과정을 피할 수 있게 하는 IDL구문을 제공함으로써 불필요한 성능저하를 방지할 수 있게 한다. 현재 능동 복제만을 지원하고 있지만 능동 복제를 지원하는 구조를 변경하지 않고 수동 복제 방식도 쉽게 지원할 수 있다.

Keywords

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