Enhancing Replica Management Services to Cope with Group Failures (1999)

Author(s): Shrivastava SK, Ezhilchelvan PD

    Abstract: In a distributed system, replication of components, such as objects, is a well known way of achieving availability. For increased availability, crashed and disconnected components must be replaced by new components on available spare nodes. This replacement results in the membership of the replicated group 'walking' over a number of machines during system operation. In this context, we address the problem of reconfiguring a group after the group as an entity has failed. Such a failure is termed a group failure which, for example, can be the crash of every component in the group or the group being partitioned into minority islands. The solution assumes crash-proof storage, and eventual recovery of crashed nodes and healing of partitions. It guarantees that (i) the number of groups reconfigured after a group failure is never more than one, and (ii) the reconfigured group contains a majority of the components which were members of the group just before the group failure occurred, so that the loss of state information due to a group failure is minimal. Though the protocol is subject to blocking, it remains efficient in terms of communication rounds and use of stable store, during both normal operations and reconfiguration after a group failure.

      • Date: October 1999
      • Series Title: School of Computing Science Technical Report Series
      • Pages: 26
      • Institution: School of Computing Science, University of Newcastle upon Tyne
      • Publication type: Report
      • Bibliographic status: Published

      Keywords: system availability, object groups, group failures, node crashes, network partitions, membership views, membership services


      Dr Paul Ezhilchelvan
      Reader in Distributed Computing

      Emeritus Professor Santosh Shrivastava
      Senior Research Investigator