On Oct 30, 2007, at 5:30 PM, Alan Robertson wrote:
Andrew Beekhof wrote:
On Oct 30, 2007, at 2:44 AM, Alan Robertson wrote:
Hi,
I've been working with a customer - trying to get them up and
running on version 2.1.2. I got everything to work except for
one thing: They require that their web server fail over on the
3rd failure. I read the documentation on the failcount stuff on
the web site here: http://www.linux-ha.org/v2/faq/forced_failover
I think I understood it, and I created a CIB to match. In the
CIB I created, I believe it should fail over on the 3rd failure.
In practice it fails over reliably on the 9th iteration instead.
We had been doing a "killall httpd" to fail the web server.
9th is correct.
As has been explained here on the list a number of times, the
group's stickiness is N * default-resource-stickiness, where N is
the number of resources in the group.
Including the rsc_location constraint, the group stickiness is
therefor: 4 * 20 + 1 = 81
So clearly apache is going to need to fail 9 times (9 * default-
resource-failure-stickiness = -90) before the group is moved.
Of course it all starts getting even more complicated when one
starts creating rsc_colocation constraints with other groups and
primitives.
Can I specify the resource-failure-stickiness of a group either
explicitly or implicitly?
no, because groups, being meta-objects, don't fail - resources do
you can set a 'special' value for all members in the group by setting
it in the group object, but its still applied at the resource level.
one thing I would like to do is make it so that the resource-
stickiness of a group is not the sum of its components.
however due to a feature someone asked for 2 years or so ago, I'm not
sure if I can.
Since I'm writing this up for the web site, I want to make sure I
have this absolutely clear so I can write it up correctly:
Do you mean that you sum up the stickiness values for each resource
in the group,
yes, the sum
or did you really mean that you it always uses n*default
stickiness? (I'm asking for both for failure stickiness and
resource stickiness).
If I have a locational constraints for a group of 'p' points, does
that then distribute across the group of 'n' nodes so that we get a
group preference of 'p' * 'n' points? Or is it just just a total
of 'p' points for the group as a whole?
this part i actually got right, just 'p' and not n*p
My current attempt to document this can be found here:
http://linux-ha.org/v2/faq/forced_failover
--
Alan Robertson <[EMAIL PROTECTED]>
"Openness is the foundation and preservative of friendship... Let
me claim from you at all times your undisguised opinions." -
William Wilberforce
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