[Linux-HA] rsc_location problem

[Zachár Balázs]

Thx.

This helped for me...



Andrew Beekhof írta:
> On 11/9/06, Zachár Balázs <zachar at direkt-kfki.hu> wrote:
>> Yes, I see it but if I right, it isn't help me.
>>
>> If the A node can't ping the ping host (-110 score) I would like to
>> migrate the resource to B node, so the resource_stickiness must allow
>> the migration.
>> But, If the A node can ping again the ping host (+110 score) the scores
>> are the same as the start scores so It will migrate back the resource,
>> and because the resource_stickiness allow the previous migration it
>> allow this migration too.
>
> assuming:
> * no rsc_location constraints,
> * the pingd score for nodeA is X
> * the pingd score for nodeA is Y
>
> if X == Y, then even a resource_stickiness of 1 will leave it on the 
> same node.
> if X < Y, then as long as resource_stickiness < (Y-X), the resource
> will always run on Y
> if X > Y, then as long as resource_stickiness < (X-Y), the resource
> will always run on X
>
> So also assuming a pingd multiplier of 100, then resource_stickiness
> should be less than 100 to do what you want.
>
> In practice, .7 had some non-intuitive multiplications going on... so
> I'd suggest a resource_stickiness of about 10 to be on the safe side.
>