[Pacemaker] Constraints with and without rules

Lars Marowsky-Bree lmb at suse.de
Fri Aug 22 22:14:10 UTC 2008


On 2008-08-22T16:35:45, Ben Beuchler <insyte at gmail.com> wrote:

> I apologize for the cross-post if that's not kosher.  It appears
> linux-ha still gets considerably more traffic than the pacemaker list.
> 
> Are these functionally equivalent on a cluster with symmetric-cluster=false?
> 
> This is the technique in the DRBD w/ v2 cluster document in the wiki
> (albeit with a score of INFINITY instead of 100):
> 
> <rsc_location id="drbd0-loc-1" rsc="drbd0">
>   <rule score="100">
>     <expression value="node0" attribute="#uname" operation="eq"/>
>     <expression value="node1" attribute="#uname" operation="eq"/>
>   </rule>
> </rsc_location>
> 
> And these are the type that seem to be favored in Mr. Beekhof's
> excellent "Configuration Explained" document:
> 
> <rsc_location id="drbd0-loc-1" rsc="drbd0" node="node0" score="100"/>
> <rsc_location id="drbd0-loc-2" rsc="drbd0" node="node1" score="100"/>
> 
> It seems both approaches should result in the same thing.  Any
> particular reason to prefer one over the other?

I prefer the first, because it has less redundancy.

But no, there is no particular reason.


Regards,
    Lars

-- 
Teamlead Kernel, SuSE Labs, Research and Development
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde





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