[jboss-cluster-dev] Re: [javagroups-users] Conversion from FD to FD_ALL

[Brian Stansberry]

Ok, thanks. Based on that my intent is to defer 
https://jira.jboss.org/jira/browse/JBAS-6604 until this is sorted. Would 
you agree?

Bela Ban wrote:
> Yes, the change from FD to FD_ALL is correct.
> 
> However, as I've found out on a recent clustering consulting gig, FD_ALL 
> has some issues with FD.shun="true" on merging. The issue we ran into 
> was a shunfest, where entire subclusters shunned all nodes in different 
> subclusters. This lead to the issue where the cluster never re-merged 
> due to excessive shunning going on.
> 
> I've created a JIRA issue [1] to look into getting rid of shunning and 
> only deal with merging. However, this is going to be in 2.9 the 
> earliest, not in the 2.6 branch.
> 
> [1] https://jira.jboss.org/jira/browse/JGRP-937
> 
> 
> Brian Stansberry wrote:
>> I have a task to convert JBoss AS's UDP-based stacks from FD to
>> FD_ALL.[1] I want to make sure I understand the configuration correctly
>> such that I can get the same behavior as we have now for the simple case
>> where one node crashes. (I realize FD_ALL can detect multiple failures
>> more quickly, which is good.)
>>
>> The AS currently uses:
>>
>> <FD timeout="6000" max_tries="5" shun="true"/>
>>
>> Would this be fairly similar:
>>
>> <FD_ALL timeout="30000" interval="6000" shun="true"/>
>>
>> In both case it takes 30 secs to suspect a node, in both cases a message
>> is sent every 6 seconds, and in both cases 5 such messages would have to
>> be lost for some reason before a healthy node would be suspected.
>>
>> [1] https://jira.jboss.org/jira/browse/JBAS-6604
> 


-- 
Brian Stansberry
Lead, AS Clustering
JBoss, a division of Red Hat
brian.stansberry at redhat.com