Jgroup integrates the object group paradigm with the distributed object model of Java
RMI, providing a platform which is suitable for developing partitionable distributed
applications. Jgroup depends on RMI in all its interactions; whether internal
for
coordination between object group replicas, or external for communicating clients with
object group. Because of the dynamic of network which is caused by joining new servers
and leaving another ones to object group, or caused by partitioning, Partitionable Group
Membership Service tracks this changes to provide each member with a report called view.
The view contains a list of members which can communicate and coordinate activities.
The advantage of group membership in Jgroup is the ability to continue in providing
service in each partition, instead of limiting it in one partition.
When partitions merge, State Merging Service of Jgroup constructs a new global
consistent state, to reconcile any divergence caused by conflict updates in the different
partitions.
Group Membership Service is required that a view is installed only after agreement
is reached on its composition among the servers included in the view (Agreement On View
property). To achieve this property; many of Estimation messages are exchanged between
the servers, which causes overhead on the network.
This article improves the performance of group membership algorithm which is
responsible for achieving the agreement, through allowing for the first server detects the
new change in membership to send its estimation to other servers, instead of doing that by
each server.
Results show that the enhanced algorithm reduces the number of exchanged estimate
messages, and takes approximately the same period of time to reach to agreement on view
as in the default algorithm.
