score="0"
is specified for a constraint, the constraint is considered optional and only has an effect when both resources are stopping and/or starting. Any change in state by the first
resource will have no effect on the then
resource.
Example 6.4. Example of an optional and mandatory ordering constraint
<constraints> <rsc_order id="order-1" first="Database" then="Webserver" /> <rsc_order id="order-2" first="IP" then="Webserver" score="0"/> </constraints>