Re: Heartbeat LVS-DR config

[Malcolm Turnbull <malcolm@xxxxxxxxxxxxxxxx>]

Ah, sounds like the wrong way of doing things.
Heartbeat MUST have communication with the other node in order to work !

So use a serial cable & optionaly a network cable as well !

Then setup a 'ping node' that both nodes can ping and if a node realises 
it can't ping the
node it will notify the other that it is going offline...

Or if it dies the other one will take over anyway.
And if both can't ping the node then who cares anyway ?





Purcocks, Graham wrote:

> I have 2 LVS directors with failover using heartbeat (the real servers
> are working fine). I only use a network UDP test, no serial connection,
> because I want a failover to occur if the network connection fails on
> the primary director. I use nice_failback so there is no fixed
> master/slave.
>
> I believe I am correct in saying only if all heartbeat checks fail then
> the system fails over, so having a serial connection will not failover
> if just the UDP check fails.
>
>  
>
> In ha.cf I have
>
> <snip>
>
> udpport 694
> #
> #       What interfaces to broadcast heartbeats over?
> #
> bcast   eth0            # Linux
>
> node    lvsrouter-1.domain
> node    lvsrouter-2.domain
>
> </snip>
>
> What happens with this, is that if lvsrouter-1 is master and you pull
> the ethernet cable, then lvsrouter-2 takes over correctly but
> lvsrouter-1 stays up as it thinks the slave has just failed. When you
> put the cable back in then lvsrouter-1 comes up as master, and
> lvsrouter-2 shuts down, but then comes back up again. So you end up with
> both running as master.
>
> The more I think about this, the more it seems incorrect. It appears
> that the routers do not negotiate correctly, so maybe the config is
> wrong in some way. If you do a 'service heartbeat stop' on lvsrouter-1,
> the failover occurs and when you restart heartbeat it correctly takes up
> the slave mode.
>
> So it appears that heartbeat does not detect it should be slave when it
> just loses network connectivity and it only has UDP checking. I'm sure I
> read somewhere this case and someone had a different network test module
> which also checked network connectiviy to the next hop router.
>
> So maybe I don't have the 2 directors configured correctly, or this is a
> scenario that is not easily coped with.
>
> Does that explain it more clearly?
>
> Thanks
> Graham
>
> -----Original Message-----
> From: lvs-users-bounces@xxxxxxxxxxxxxxxxxxxxxx
> [mailto:lvs-users-bounces@xxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Malcolm
> Turnbull
> Sent: 13 April 2005 13:56
> To: LinuxVirtualServer.org users mailing list.
> Subject: Re: Heartbeat LVS-DR config
>
> Graham,
>
> I'd wouldn't say giberish.. but you haven't said what you are doing ?
>
> I assume you mean LVS-DR on one load balancer, with two real servers 
> (one set up as failover)
> using either mon, ldirectord or keepalived ?
> Or are you talking about some kind of heartbeat setup ?
> Or do you mean hosting the services (apache) on the LVS boxes with 
> heartbeat ?
>
> Purcocks, Graham wrote:
>
>  
>
> > I have just built 2 new servers with LVS-DR and they fail over fine if
> > the machine dies, but if the network interface stops they both end up
> > being live when the interface is restored. This is with only IP
> > checking.
> >
> > Sorry if it sounds gibberish but its driving me nuts. I know I've seen
> > it while Googling but I just can't find it again.
> >
> > Thanks
> > Graham
> >
> >
> >    
>
>  

--
Regards,

Malcolm Turnbull.

Loadbalancer.org Limited
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