A method is disclosed for providing likely updates to views of group
members in unstable group communication systems. A group message is
received from a sender associated with a sending node in a network. The
group message includes a message view having a counter and an
acknowledgment set. The acknowledgment set identifies one or more
receiving nodes to which the group message is directed. Issuance of an
acknowledgment of the group message to the sending node is deferred. The
group message is delivered to the receiving nodes. An acknowledgment of
the message is received from one of the receiving nodes. The message view
is updated by removing each receiving node that issues an acknowledgment
from the acknowledgement set. The updated message view is provided to the
sender.