Patent ID: 6980518

Claim:
In a group-based multicast messaging system implementing dedicated logger member for logging all multicast messages sent in said system, a method for reliably delivering messages from senders to receivers of said group, said method comprising steps of: a) collecting latest state information for all senders in said, said state information including latest sequence numbers transmitted by said senders; b) a receiver detecting a gap in said sequence of multicast messages received by a member of said group; c) soliciting retransmissions of missing messages to another member or logger of said group by generating a gossip message comprising a retransmission request of said missing message, said gossip message including said collected state information; d) selecting a member of said group and sending said gossip message to said selected member; and, e) determining said receiver's missing messages as fresh or stale, and one of: enabling repair of fresh missing messages by said another member in a first message recovery phase or, enabling repair of stale missing messages by a logger in a second message recovery phase, wherein reliable delivery of messages in said multicast messaging system is ensured.