Patent ID: 8428065

Claim:
A method for communication, comprising: arranging a group of servers to receive concurrently incoming multicast messages from multiple message sources outside the group of servers, and to process the incoming multicast messages to produce multiple outgoing streams of outgoing multicast messages for delivery to recipients outside the group of the servers, wherein at least some of the incoming multicast messages are received at different servers in the group in different respective message orders; designating one of the servers as a leader; periodically determining, by the leader, a common message order for processing of the incoming multicast messages by the servers; periodically transmitting from the leader to the other servers in the group a control message indicative of the common message order determined by the leader, wherein the control message is transmitted with a quality of service (QoS) that is selected so as to ensure consistent delivery of the multicast messages over all the servers in the group; and responsively to the control message, processing all the incoming messages at all the servers according to the common message order irrespective of the different orders in which the incoming messages are received and, responsively to the processing, delivering the outgoing multicast messages in the outgoing message streams from the servers to all the recipients.