[ https://issues.jboss.org/browse/JGRP-1830?page=com.atlassian.jira.plugin.... ] Bela Ban commented on JGRP-1830: -------------------------------- To deliver a non-monotonic order, e.g. 3, 5, 6 (delivered as 6, 5, 3), we could send the previous seqno with the current seqno, e.g. {noformat} 6(5) -> 5(3) -> 3(2) {noformat} Say the current seqno is 2: * Reception of 6(5). We queue 6 as we cannot deliver it since we haven't received 5 yet * Reception of 5(3). We queue 5 as we haven't received 3 yet * Reception of 3(2). We deliver 3 as it's the next seqno to the current seqno 2 * We deliver 5 as it's the next seqno to 3 (note that we won't get a 4) * We deliver 6 as well, as it's the next seqno to 5 This simple mechanism allows us to deliver non-monotonically increasing seqnos. Having the ability to do so simplifies the implementation of coord failover. -- This message was sent by Atlassian JIRA (v6.4.11#64026)