[jboss-jira] [JBoss JIRA] (JGRP-1591) VERIFY_SUSPECT is not able to check IP multicasting

[Bela Ban (JIRA)]

     [ https://issues.jboss.org/browse/JGRP-1591?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Bela Ban resolved JGRP-1591.
----------------------------

    Resolution: Done


Added use_mcast_rsps (default: false)
                
> VERIFY_SUSPECT is not able to check IP multicasting
> ---------------------------------------------------
>
>                 Key: JGRP-1591
>                 URL: https://issues.jboss.org/browse/JGRP-1591
>             Project: JGroups
>          Issue Type: Feature Request
>    Affects Versions: 3.2.7
>         Environment: Operating system
>            Reporter: Benoit Leblanc
>            Assignee: Bela Ban
>             Fix For: 3.2.8, 3.3
>
>
> Cut-off or troubles may occur on IP multicast while unicasting still operational. This greatly affects system stability.
> To reproduce it: On Cisco switch, commands like "no ip multicast-routing" or "no ip multicast-routing distributed" disable multi-cast support.
> Analysis: When 'B' misses heartbeat (multi-cast message) coming from 'A', it marks it as suspected (failure detection protocol) then notify VERIFY_SUSPECT. This protocol checks if 'A' is really DEAD. This is done by sending (unicast) ARE_YOU_DEAD request to suspected member. 'A' sends back response I_AM_NOT_DEAD (unicast again). Thus, members 'A' and 'B' remain in the same group in spite of being "multicastly" disconnected.
> Expectation: We expect that a member that belongs to a view can send unicast and multicast message to other members of the same view. So if one support is broken, unreachable members should be excluded.
> Improvement : VERIFY-SUSPECT protocol checks both unicast and muticast support: suspected member sends back I_AM_NOT_DEAD message using IP multicasting

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira