Group Membership Management Schemes

Static Membership
In this scheme, only a defined set of members can be in a group. The Group Membership Service(GMS) will detect members joining or leaving the group. External members cannot join the group. Each node may obtain the group member details from a central repository or configuration file.

Dynamic Membership
In this scheme, the membership is not predefined. Members can join a group by specifying the appropriate group name, and also can leave the group. The GMS will detect new members joining or leaving the group. The group membership information may be obtained from the GMS.

Hybrid Membership
This scheme is also called Well-Known Addressed(WKA) based membership. In this scheme, there is a set of well known members. We can consider these members as belonging to a static group. External members can join this group by notifying one of the well known members. These external members can then get the current group membership from this well known member. When new members join the group, the well known members will notify all other members. When members leave the group, the GMS can detect this event.