[ClusterLabs] Three node cluster becomes completely fenced if one node leaves

[Dejan Muhamedagic]

Hi,

On Fri, Mar 31, 2017 at 02:39:02AM -0400, Digimer wrote:
> On 31/03/17 02:32 AM, Jan Friesse wrote:
> >> The original message has the logs from nodes 1 and 3. Node 2, the one
> >> that
> >> got fenced in this test, doesn't really show much. Here are the logs from
> >> it:
> >>
> >> Mar 24 16:35:10 b014 ntpd[2318]: Deleting interface #5 enp6s0f0,
> >> 192.168.100.14#123, interface stats: received=0, sent=0, dropped=0,
> >> active_time=3253 secs
> >> Mar 24 16:35:10 b014 ntpd[2318]: Deleting interface #7 enp6s0f0,
> >> fe80::a236:9fff:fe8a:6500%6#123, interface stats: received=0, sent=0,
> >> dropped=0, active_time=3253 secs
> >> Mar 24 16:35:13 b014 corosync[2166]: notice  [TOTEM ] A processor failed,
> >> forming new configuration.
> >> Mar 24 16:35:13 b014 corosync[2166]:  [TOTEM ] A processor failed,
> >> forming
> >> new configuration.
> >> Mar 24 16:35:13 b014 corosync[2166]: notice  [TOTEM ] The network
> >> interface
> >> is down.
> > 
> > This is problem. Corosync handles ifdown really badly. If this was not
> > intentional it may be caused by NetworkManager. Then please install
> > equivalent of NetworkManager-config-server package (it's actually one
> > file called 00-server.conf so you can extract it from, for example,
> > Fedora package
> > https://www.rpmfind.net/linux/RPM/fedora/devel/rawhide/x86_64/n/NetworkManager-config-server-1.8.0-0.1.fc27.noarch.html)
> 
> ifdown'ing corosync's interface happens a lot, intentionally or
> otherwise.

I'm not sure, but I think that it can happen only intentionally,
i.e. through a human intervention. If there's another problem
with the interface it doesn't disappear from the system.

Thanks,

Dejan

> I think it is reasonable to expect corosync to handle this
> properly. How hard would it be to make corosync resilient to this fault
> case?
> 
> -- 
> Digimer
> Papers and Projects: https://alteeve.com/w/
> "I am, somehow, less interested in the weight and convolutions of
> Einstein’s brain than in the near certainty that people of equal talent
> have lived and died in cotton fields and sweatshops." - Stephen Jay Gould
> 
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