On Thu, Nov 11, 2010 at 11:31 PM, Andrew Beekhof <and...@beekhof.net> wrote: >> colocation X-Y -2: X Y >> colocation Y-X -2: Y X > > the second one is implied by the first and is therefore redundant
If only that were true! What happens with the first rule is that other constraints that force Y to a node will evict X but not the other way around. What I'm doing is to first apply a "slight" preference for each resource to each node: location X-nodeA X 1: nodeA location Y-nodeB Y 1: nodeB And then impose absolute constraints that come from the outside environment. In the particular case that has a problem, the constraint looks like: location X-not-nodeA X -inf: nodeA The behavior I expected was for X to be placed on nodeB and Y to "anti-colocate" onto nodeA because our colocation rule is stronger than the node preference rule. What happens instead is that both X and Y run on nodeB. The similar constraint on Y (by itself) does work: location Y-not-nodeB Y -inf: nodeB and results in Y running on nodeA and X running on nodeB. This is the case whether I have one colocation rule or two, i.e. the second colocation rule is ignored. Looking at the code, I think the solution would be to short-circuit the recursion when you can only run on one node due to -inf rules rather than on a loop. Obviously, it would not be a simple change and needs some thought. If you have any other suggestions let me know. Alan _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker
