[ClusterLabs] Resources still retains in Primary Node even though its interface went down

[Ken Gaillot]

On 05/03/2017 02:43 AM, pillai bs wrote:
> Hi Experts!!!
> 
>               Am having two node setup for HA (Primary/Secondary) with
> separate resources for Home/data/logs/Virtual IP.. As known the Expected
> behavior should be , if Primary node went down, secondary has to take
> in-charge (meaning initially the VIP will point the primary node, so
> user can access home/data/logs from primary node.Once primary node went
> down, the VIP/floatingIP will point the secondary node so that the user
> can experienced uninterrupted service).
>              I'm using dual ring support to avoid split brain. I have
> two interfaces (Public & Private).Intention for having private interface
> is for Data Sync alone.
> 
> I have tested my setup in two different ways:
> 1. Made primary Interface down (ifdown eth0), as expected VIP and other
> resources moved from primary to secondary node.(VIP will not be
> reachable from primary node)
> 2. Made Primary Interface down (Physically unplugged the Ethernet
> Cable). The primary node still retain the resources, VIP/FloatingIP was
> reachable from primary node.
> 
> Is my testing correct?? how come the VIP will be reachable even though
> eth0 was down. Please advice!!!
> 
> Regards,
> Madhan.B

Sorry, didn't see this message before replying to the other one :)

The IP resource is successful if the IP is up *on that host*. It doesn't
check that the IP is reachable from any other site. Similarly,
filesystem resources just make sure that the filesystem can be mounted
on the host. So, unplugging the Ethernet won't necessarily make those
resources fail.

Take a look at the ocf:pacemaker:ping resource for a way to ensure that
the primary host has connectivity to the outside world. Also, be sure
you have fencing configured, so that the surviving node can kill a node
that is completely cut off or unresponsive.