Abstract: Membership of a group of processors in a distributed computing environment is managed. Specific actions are identified and performed in order to manage the group membership. A processor requests to join the group of processors and thus, is added to the group. Similarly, processors may request to leave the group or may fail and then are removed from the group. The group of members also receives multicasts initiated from one member of the group to other members of the group. Additionally, each group of processors within a distributed computing environment has a group leader that controls the actions being performed for the group of members.

Abstract: Program product for managing membership of a group of processors in a distributed computing environment. Specific actions are identified and performed in order to manage the group membership. A processor requests to join the group of processors and thus, is added to the group. Similarly, processors may request to leave the group or may fail and then are removed from the group. The group of members also receives multicasts initiated from one member of the group to other members of the group. Additionally, each group of processors within a distributed computing environment has a group leader that controls the actions being performed for the group of members.

Abstract: A barrier synchronization technique in a distributed computing environment. A group of members, including a plurality of related processes executing on one or more processors of the distributed computing environment, is provided a protocol having a dynamic number of synchronization phases. The protocol is voted on by one or more members of the group to determine how the protocol should proceed for the group of members. The protocol may complete successfully, continue to another synchronization phase or be rejected. The group of members determines how many synchronization phases the protocol is to include.

Abstract: In a distributed computing environment having a plurality of groups of processors, each processor group maintains its own set of ordered messages. A message is sent to a group of processors. In particular, a request to multicast a message is sent to a leader of the group of processors, i.e., a group leader, and the group leader assigns a sequence number to the message to be sent, thereby providing an ordered message. Then, the group leader multicasts the ordered message to the group of processors. When the processors of the group receive the ordered message, each determines whether the message is in proper sequence order. If the message is out of order for a particular processor indicating that a message has been missed, then that particular processor requests the missing message from a processor within the group.