Hi Attila,

Sorry for the delay, somehow missed your message.

On Fri, Dec 28, 2012 at 12:52:22PM +0100, Attila Megyeri wrote:
> Hi Dejan,
> 
> -----Original Message-----
> From: linux-ha-dev-boun...@lists.linux-ha.org 
> [mailto:linux-ha-dev-boun...@lists.linux-ha.org] On Behalf Of Dejan 
> Muhamedagic
> Sent: Monday, December 24, 2012 11:07 AM
> To: linux-ha-dev@lists.linux-ha.org
> Subject: Re: [Linux-ha-dev] IPsrcaddr bug, and fix recommendation
> 
> Hi,
> 
> On Thu, Dec 20, 2012 at 08:03:32PM +0100, Attila Megyeri wrote:
> > hi,
> > 
> > I have a cluster configuration with two IPsrcaddr resources (e.g. IP 
> > address "A" and "B") They are configured to two different addresses, and 
> > are never supposed to run on the same nodes. So "A" can run on nodes N1 and 
> > N2, "B" can run on  N3,N4.
> > 
> > My problem is, that in some cases, crm_mon shows that an ipsrcaddr resource 
> > is running on a node where it shouldn't, and of course it is in unmanaged 
> > state and cannot be stopped.
> > For instance:
> >                 IP address "A" is started, unamanged on node N3.
> > 
> > I am using pacemaker 1.1.6 on a debian system, with the latest RA from 
> > github.
> > 
> > I checked the RA, and here are my findings.
> > 
> > 
> > -          When status is called, it calls the srca_read() function
> > 
> > -          srca_read() returns 2, if a srcip is running on the given node, 
> > but with a different IP address.
> > 
> > -          srca_status(), when gets "2" from srca_read(), returns 
> > "$OCF_ERR_GENERIC"
> > 
> > As a result, in my case IP "B" is running on N3, which is OK, but 
> > CRM_mon reports that IP "A" is also running on N3 (unmanaged). [for some 
> > reason this is how the OCF_ERR_GENERIC is interpreted] This is definitively 
> > a bug, the question is whether in pacemaker or in the RA.
> > If I change the script to return "$OCF_NOT_RUNNING" instead of  
> > $OCF_ERR_GENERIC" it works properly.
> > 
> > What is the proper behavior in this case?
> > My recommendation is to fix the RA so that srca_read() returns 1, if there 
> > is a srcip on the node, but it is not the queried one.
> 
> The comment in the agent says:
> 
> #   NOTES:
> #
> #   1) There must be one and not more than 1 default route! Mainly because
> #   I can't see why you should have more than one.  And if there is more
> #   than one, we would have to box clever to find out which one is to be
> #   modified, or we would have to pass its identity as an argument.
> #
> 
> This should actually be in the meta-data, as it is obviously intended for 
> users.
> 
> It looks like your use case doesn't fit this description, right?
> Perhaps we could add a parameter like "allow_multiple_default_routes".
> 
> Thanks,
> 
> Dejan
> 
> 
> On the host where the resource is running I have only one default gateway. 
> The other pair of this host (the other node) uses a different default gateway 
> - but I do not think this should be a limitation (on that host I have a 
> single default gateway as well).

The "must be one and not more than 1" should also say
"cluster-wide".

> The srca_read() function does not fail in the steps that check the default 
> gateway. The function runs till the last line where 2 is returned, although 
> it is not a generic error, rather the SRC ip is not running on the node.

The exit code 2 signifies that the default route has an
unexpected address.

I think that it works as designed. As mentioned earlier, we can
extend the resource agent to support clusters with multiple
default routes, but that would need to be done with an extra
configuration parameter. Patches welcome :)

Thanks,

Dejan

> 
> Thanks,
> 
> Attila
> 
> 
> 
> 
> 
> 
> 
> > In this case the RA would return a "$OCF_NOT_RUNNING"
> > 
> > 
> > 
> > Cheers,
> > Attila
> > 
> 
> > _______________________________________________________
> > Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org 
> > http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
> > Home Page: http://linux-ha.org/
> 
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