[jboss-user] [Clustering/JBoss] - NAKACK errors on retransmit when cluster is under heavy load

[hmesha]

Env:
Hardware: 2 x86 based machines
OS: Suse Linux Enterprise Server 9 SP3
Server: JBoss 4.0.5.GA
JGroups : 2.4.1

We're running a performance test on the cluster above. 100 concurrent virtual users with 1 second pause time between actions. After sometime (4hours) in the test I observed the following error on the server console.




  | 2007-02-16 17:12:32,294 ERROR [org.jgroups.protocols.pbcast.NAKACK:error] (requester=-.-.-.205:33509, local_addr=-.-.-.205:33509) message -.-.-.205:33509::1172743 not found in sent msgs. 
  | Sent messages: [1172262 - 1172861] (600)
  | 2007-02-16 17:44:39,599 ERROR [org.jgroups.protocols.pbcast.NAKACK:error] (requester=-.-.-.205:33509, local_addr=-.-.-.205:33509) message -.-.-.205:33509::1628057 not found in sent msgs. 
  | Sent messages: [1627729 - 1628398] (670)
  | 

Note: I omitted the servers subnet for security reasons.

The errors above occur not freqently (once or twice every 4 hours) on the servers but I'd like to understand why they happen. It looks to me like a concurrency issue with NAKACK when looking at the code base for JGroups 2.4.1.

Can someone explain the error?

Thanks,


View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4020142#4020142

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4020142