How to create Groups and Group Leaders in Clusters.

Question

Hi,
As we know in unicast there is one to one communication and there are groups to control the Thread
Management, How the Groups and the Group Leaders are created.
Regards,
Vardhan.

Answer 1

Unicast clustering uses TCP/IP sockets to pass cluster messages between members. To avoid requiring each cluster member
to have connectivity to every other cluster member, WebLogic Server uses a group leader strategy whereby the oldest member
of the group (in other words, the server that was started first) is designated the group leader. All members of the cluster
connect to the group leader so that the group leader acts as the relay point for cluster messages between members.
If the group leader goes down, the next oldest member becomes the new group leader.
As you can imagine, the group leader strategy works well for small groups but becomes less efficient as the number of members
of the group grows large. As such, WebLogic Server uses a multiple group leader strategy where it limits the number of members
in a group to 10. If the cluster is larger than 10 members, WebLogic Server splits into two or more groups, each with their own
group leader. The group leaders themselves are all interconnected to minimize the number of hops that a cluster message must
traverse to reach all cluster members.