[jboss-jira] [JBoss JIRA] Commented: (JGRP-699) NAKACK: merging of digests is incorrect

NAKACK: merging of digests is incorrect --------------------------------------- Key: JGRP-699 URL: http://jira.jboss.com/jira/browse/JGRP-699 Project: JGroups Issue Type: Bug Affects Versions: 2.4, 2.4.1, 2.4.1 SP1, 2.4.1 SP2, 2.4.1 SP3, 2.4.1 SP4, 2.4.2 Reporter: Bela Ban Assigned To: Bela Ban Fix For: 2.7, 2.6.3, 2.4.3 The merge view is: 2008-02-20 23:49:30,872 DEBUG [org.jgroups.protocols.pbcast.GMS] view=MergeView::[172.16.172.233:19382|3] [172.16.172.233:19382, 172.16.172.234:19382], subgroups=[[172.16.172.233:19382|1] [172.16.172.233:19382, 172.16.172.234:19382], [172.16.172.234:19382|2] [172.16.172.234:19382]], digest=172.16.172.233:19382: [557 : 564(564)], 172.16.172.234:19382: [901 : 923 (923)] So, the digest for 234:19382 is 901-923, which means 234 could actually satisfy the retransmit request below. However, when the xmit req arrives: 2008-02-20 23:49:32,004 ERROR [org.jgroups.protocols.pbcast.NAKACK] (requester=172.16.172.233:19382, local_addr=172.16.172.234:19382) message 172.16.172.234:19382::919 not found in retransmission table of 172.16.172.233:19382:[557 : 565 (565)] 172.16.172.234:19382: [921 : 924 (924) (size=3, missing=0, highest stability=921)] , we can see that now the digest for 234:19382 is 921-924. In 2.4, the merge algorith for digests (NAKACK.mergeDigest()) takes the *max* of the low seqnos (MAX(901,921), in 2.5 and higher we don't touch an existing entry, so the digest for 234:19382 would still be 901-923, and we could therefore satisfy the merge request. SOLUTION: use the solution implemented in 2.5 and higher: don't set digests for existing entries.