Implementation and evaluation of an asynchronous group membership protocol

A group membership protocol provides the mechanisms to ensure the consistent group views among a group-oriented distributed processes. The protocol is required to dynamically re-configure the group views among the various members in the event of a change to the group due to a new member joining or a member departing. The departure may be voluntary or involuntary. The protocol must provide a scheme to detect the failure of any of the members and re-configure the group. Multiple changes to the group must be perceived at all members in the same order. This thesis deals with a particular group membership protocol. The protocol structures the group as a logical ring. Changes to the group are accomplished using a two-phase scheme. The agreement phase consists of circulation of an agree token. Processing the token makes a pending change known to all members. The commit phase incorporates the changes in the correct order. This thesis presents an implementation of this asynchronous group membership protocol. The main feature is that the decentralized nature of the protocol eliminates the need for a dedicated coordinator of changes. The processing requirements for the protocol are likewise distributed. The processing time required to implement a change to the group is shown to have a linear relationship to the group size.