On 4/20/07, Yan Fitterer <[EMAIL PROTECTED]> wrote:
>> In the attached pe- warn, why is resource R_audit being started on
>> idm01 when there is an INFINITY constraint with uname eq idm04?
>>
>> BTW - idm04 is in standby at the moment. That should hardly matter. I
>> expect the resource to be "cannot run anywhere".
>>
>> I really hope it's not a typo, but I have read it as much as I can,
>> and I can't see it...
>>
>> Thanks Yan
>
> So, there is only one place it can be run, and it has score 0. (It
> can't run on a machine in standby).
>
> So, it gets run there.
>
> What's the problem?
The problem is that I need the resource to _ONLY_ run on IDM04, or not at all.
Yes, I know, this is not clustering, or HA, but there is a good reason.
If you want the long story, the reason for that is that resource R_audit (an
instance of Novell Audit) is not meant to be clustered here, but depends on
resource R_workforce_edir (eDirectory instance), which IS clustered. The issue
is that Novell Audit must start after eDirectory (Audit configuration is stored
in eDir). So the best way I could think of achieving that, was to created a
resource for Audit, with an order constraint between eDirectory and Audit. But
since Audit isn't really clustered (executables on one node only), I need to
make it run on IDM04, or nowhere. That what I thought INFINITY would mean.
If -INFINITY achieves that, but INFINITY doesn't, then it looks like broken logic to me,
where INFINITY is not the exact opposite of -INFINITY. If this is really "works as
designed", it is very highly counter-intuitive, and IMHO should be considered a bug.
Actually, INFINITY in colocation constraints _does_ mean, "work here or
nowhere". Why would it be different for location constraints?
because there is no concept of if you can't run with rscX, try rscY
and then rscZ.
ideally that might be nice capability to have, but we don't allow that
in order to make resource placement solvable.
"symmetric_cluster=true & -INFINITY"
is the inverse of
"symmetric_cluster=false & +INFINITY"
if you say: symmetric_cluster=true
then you're saying resources can run anywhere by default.
if there is somewhere a resource can't run, then you have to
explicitly say so with -INFINITY.
its the reverse of symmetric_cluster=false, where resources can't run
anywhere by default and you need explicitly say where they can run.
this particular aspect of configuration has been documented for a long
time, but perhaps Alan would feel better if it was added to his idioms
document as well.
sure, we could make
rsc_location(rscX, nodeX, INFINITY)
also modify
node in ( [nodes] - nodeX )
but then if you say:
rsc_location(rscX, nodeX, INFINITY)
rsc_location(rscX, nodeY, 10000)
rsc_location(rscX, nodeZ, 100)
then it cant still only ever run on nodeX, because -INFINITY+10000 ::= -INFINITY
Confused...
Thanks for the answer
Yan
_______________________________________________
Linux-HA mailing list
[email protected]
http://lists.linux-ha.org/mailman/listinfo/linux-ha
See also: http://linux-ha.org/ReportingProblems
_______________________________________________
Linux-HA mailing list
[email protected]
http://lists.linux-ha.org/mailman/listinfo/linux-ha
See also: http://linux-ha.org/ReportingProblems
