Patent ID: 6934768

Claim:
A method of dynamically modifying a fragmentation size cluster communication parameter in a clustered computer system, the method comprising: deferring processing of a requested fragmentation size change until receipt of an acknowledgment message for at least one unacknowledged message sent by a source node to a plurality of target nodes; thereafter processing the requested fragmentation size change to modify a fragmentation size cluster communication parameter used in transmitting messages from the source node to the plurality of target nodes; thereafter sending messages from the source node to the plurality of target nodes using the modified fragmentation size cluster communication parameter; and sending a sync message from the source node to the plurality of target nodes; wherein deferring processing of the requested fragmentation size change includes waiting for an acknowledgment message for the sync message from each of the plurality of target nodes, wherein processing the requested fragmentation size change includes sending a fragmentation size change message from the source node to the plurality of target nodes, the fragmentation size change message configured to modify the fragmentation size cluster communication parameter on each of the plurality of target nodes, wherein the source node comprises a message queue, wherein sending the sync message includes placing the sync message on the message queue and sending the fragmentation size change message includes placing the fragmentation size change message on the message queue, wherein the source node and the plurality of target nodes are members of a first group, wherein the source node is a member of a second group that further includes as members a second plurality of target nodes, wherein the source node further comprises a second message queue, wherein the source node includes first and second connections respectively associated with the first and second groups, wherein sending the sync message further includes placing the sync message on the second message queue to initiate, upon receipt by each target node in the second group, an immediate acknowledgment message from such target node that acknowledges receipt for each unacknowledged message received by such target node, and wherein sending the fragmentation size change message further includes placing the fragmentation size change message on the second message queue to modify the fragmentation size cluster communication parameter on each of the plurality of target nodes in the second group.