[Pacemaker] Resource capacity limit

[Andrew Beekhof]

On Fri, Oct 30, 2009 at 12:41 PM, Yan Gao <ygao at novell.com> wrote:
> Hi Andrew and Lars,
> The attachment is the first try to implement "Resource capacity limit"
> which is issued by Lars from:
> https://fate.novell.com/303384
>
> Description:
> We need a mechanism for the PE to take resource weight into account to
> prevent nodes from being overloaded.
>
> Resources would require certain minimal values for node attributes
> (this is available right now); however, they would also "consume" them,
> reducing the value of the node attributes for further resource placement.
> (This could be a special flag in the rsc_location rule, for example.)
> If a node does not have enough capacity available, it is not considered.
> ..
>
> User case:
> Xen guests have memory requirements; nodes cannot host more guests than
> the node has physical memory installed.
>
>
> Configuration example:
>
> node yingying \
>        attributes capacity="100"
> primitive dummy0 ocf:heartbeat:Dummy \
>        meta weight="90" priority="2"
> primitive dummy1 ocf:heartbeat:Dummy \
>        meta weight="60" priority="1"
> ..
> property $id="cib-bootstrap-options" \
>        limit-capacity="true"
> ..
>
> Because dummy0 has the higher priority, it'll be running on node "yingying".
> While this node only has "10" (100-90) capacity remaining now, so dummy1 cannot
> be running on this node. If there's no other node where it can be running on,
> dummy1 will be stopped.
>
> If we don't want to enable capacity limit. We could set property
> "limit-capacity" to "false", or default it.
>
>
> What do you think about the way it's implemented? Did I do it right?

Just one question, why the new cluster property?
Didn't we already have placement-strategy for that purpose?

>
> I also noticed a likely similar planned feature described in
> http://clusterlabs.org/wiki/Planned_Features
>
> "Implement adaptive service placement (based on the RAM, CPU etc.
> required by the service and made available by the nodes) "
>
> Indeed, this try only supports single kind of capacity, and it's not
> adaptive... Do you already have a thorough consideration about this
> feature?
> Any comments or suggestions are appreciated. Thanks!
>
> Regards,
>  Yan
> --
> ygao at novell.com
> Software Engineer
> China Server Team, OPS Engineering
>
> Novell, Inc.
> Making IT Work As One™
>
>
>
>
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