[Pacemaker] A few questions

[Dejan Muhamedagic]

Hi,

On Wed, May 20, 2009 at 03:09:30PM -0400, Ryan Steele wrote:
> Hey folks,
>
> Been toying with OpenAIS and Pacemaker for a day or two, and I have a few 
> questions that I couldn't find verbiage on in the documentation, which I 
> hope some wiser minds might be able to answer.
>
> 1.  Is there a bug in crm_attribute, specifically with --attr-name (-n)?  I 
> can't seem to get it to return values for any key, though I'm certain they 
> exist:
>
> root:~$ pengine metadata | grep "parameter name" | awk -F\" '{print $2}'
> no-quorum-policy
> symmetric-cluster
> stonith-enabled
> stonith-action
> stonith-timeout
> startup-fencing
> default-resource-stickiness
> is-managed-default
> maintenance-mode
> cluster-delay
> batch-limit
> stop-all-resources
> default-action-timeout
> stop-orphan-resources
> stop-orphan-actions
> remove-after-stop
> pe-error-series-max
> pe-warn-series-max
> pe-input-series-max
> start-failure-is-fatal
>
> root:~$ crm_attribute -V -G -n cluster-delay
>  name=cluster-delay value=(null)
> Error performing operation: The object/attribute does not exist
> root:~$ crm_attribute -V -G -n batch-limit
>  name=cluster-delay value=(null)
> Error performing operation: The object/attribute does not exist
>
> ...so on and so forth; they all respond similarly.

The fact that pengine metadata shows all possible parameters,
doesn't mean that they are defined. Most of the configuration is
initially empty. Try

crm configure show

and you'll see which config parameters are defined.

> 2.  Is there a need for better documentation?  The 87-page PDF "Pacemaker 
> Configuration Explained" seems to be missing some OpenAIS-centric 
> information, despite the fact that there seems to be a big push for folks 
> to use OpenAIS instead of Heartbeat.  For example, in the "Cluster Nodes" 
> chapter, under the "Removing a Cluster Node" section, the OpenAIS 
> instructions are simply 'TBA', and step 4 in the "Replacing a Cluster Node" 
> section for OpenAIS is blank.  It seems counter-intuitive to be missing 
> documentation for the piece of software in the pair that's supposed to 
> usurp the other's position.

Yes, documentation is lacking still. The crm shell should be able
to delete a node. Try:

crm node delete <node>

If it doesn't work (there were recently some changes in that
area), please report a bug.

> There also seems to be no good entry point for folks who desire an 
> active/passive failover pair.  I believe it's instrumental to be able to 
> get a simple example working, so one can test and build out from there,  
> but most of the documentation examples are just snippets of larger 
> configurations which nobody will have at the get-go.  I'm happy to 
> contribute some basic examples once I've wrapped my head around them, and 
> contribute some of the missing pieces once I know what to write, but I also 
> wouldn't mind if someone (anyone) more familiar with the software would 
> like to do the same to help speed up the learning curve/adoption rate for 
> those of us still acclimating.

I guess that there are some examples out there. If not, I'm sure
some are on its way ;-) Sorry that I can't offer any right now.

Thanks,

Dejan

>
> Thanks,
> Ryan
>
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