JBossCacheService: exception occurred in cache put error occurred after changing cache mode to REPL_SYNC

Question

Hi, we have a horizontal cluster set up on JBoss 4.2. The session replication worked fine until we changed cache mode from REPL_ASYNC to REPL_SYNC to fix a issue. We started to see warning for some session failovers:

[org.jboss.web.tomcat.service.session.InstantSnapshotManager.ROOT] Failed to replicate session
java.lang.RuntimeException bc [local7.warning] JBossCacheService: exception occurred in cache put ... 
org.jboss.web.tomcat.service.session.JBossCacheWrapper.put(JBossCacheWrapper.java:147)
org.jboss.web.tomcat.service.session.JBossCacheService.putSession(JBossCacheService.java:315)
org.jboss.web.tomcat.service.session.JBossCacheClusteredSession.processSessionRepl(JBossCacheClusteredSession.java:125)

Does anyone have any idea why this happen and how to fix it if we want to still use REPL_SYNC? Any help is appreciated. Thanks!

Answer 1

I found out the error exists right before the REPL_ASYNC switch. According to people from JBoss, the warning is normal during excessive garbage collection or network issues. The node did not respond to the replication request, and was suspected of being down by JGroups.