[Pacemaker] Node crash when 'ifdown eth0'

[Steven Dake]

On Mon, 2009-11-30 at 17:05 -0700, hj lee wrote:
> 
> 
> On Fri, Nov 27, 2009 at 3:05 PM, Steven Dake <sdake at redhat.com> wrote:
>         On Fri, 2009-11-27 at 11:32 -0200, Mark Horton wrote:
>         > I'm using pacemaker 1.0.6 and corosync 1.1.2 (not using
>         openais) with
>         > centos 5.4.  The packages are from here:
>         > http://www.clusterlabs.org/rpm/epel-5/
>         >
>         > Mark
>         >
>         > On Fri, Nov 27, 2009 at 9:01 AM, Oscar Remí­rez de Ganuza
>         Satrústegui
>         > <oscarrdg at unav.es> wrote:
>         > > Good morning,
>         > >
>         > > We are testing a cluster configuration on RHEL5 (x86_64)
>         with pacemaker
>         > > 1.0.5 and openais (0.80.5).
>         > > Two node cluster, active-passive, with the following
>         resources:
>         > > Mysql service resource and a NFS filesystem resource
>         (shared storage in a
>         > > SAN).
>         > >
>         > > In our tests, when we bring down the network interface
>         (ifdown eth0), the
>         
>         
>         What is the use case for ifdown eth0 (ie what are you trying
>         to verify)?
> 
> I have the same test case. In my case, when two nodes cluster is
> disconnect, I want to see split-brain. And then I want to see the
> split-brain handler resets one of nodes. What I want to verify is that
> the cluster will recover network disconnection and split-brain
> situation.
> 

ifconfig eth0 down is a totally different then testing if there is a
node disconnection.  When corosync detects eth0 being taken down, it
binds to the interface 127.0.0.1.  This is probably not what you had in
mind when you wanted to test split brain.  Keep in mind an interface
taken out of service is different then an interface failing from a posix
api perspective.

What you really want to test is pulling the network cable between the
machines.

Regards
-steve

> Thanks
> hj
> 
>