[jboss-jira] [JBoss JIRA] Commented: (JGRP-1107) TCP: skip_suspected_members=true prevents merge

[Bela Ban (JIRA)]

    [ https://jira.jboss.org/jira/browse/JGRP-1107?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12498518#action_12498518 ] 

Bela Ban commented on JGRP-1107:
--------------------------------

We cannot do this because the discovery protocol won't ever find other members, e.g. if TCPPING is used:
- TCPPING on A tries to contact A and B, but drops the call to B because B is in its suspected_members list, and vice versa

The fundamental issue is that we cannot unilaterally add someone to the suspected_members list and never remove it, because we might later want to talk to that member again...

I guess the only solution here is to deprecate and remove skip_suspected_members.

> TCP: skip_suspected_members=true prevents merge
> -----------------------------------------------
>
>                 Key: JGRP-1107
>                 URL: https://jira.jboss.org/jira/browse/JGRP-1107
>             Project: JGroups
>          Issue Type: Bug
>            Reporter: Bela Ban
>            Assignee: Bela Ban
>             Fix For: 2.8
>
>
> When we have A and B and both have TCP.skip_suspected_members set to true, then the following happens on a network partition:
> - A excludes B and adds B to suspected_members. Therefore A won't send any messages to B anymore
> - B does the same
> - A and B would remove the sender of a message from suspected_members, but nobody will actually send any messages !
> - On a merge, A and B need to talk to each other, but both will discard the message !
> ==> A merge will never happen
> WORKAROUND: set skip_suspected_members to false
> SOLUTION: before a merge, clear suspected_members (maybe handle MERGE event)

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira