Thank you! What quantity does pacemaker tries to equalize - number of running resources per node or total stickiness per node?
Suppose I have a bunch of web server groups each with IPaddr and apache resources, and a fewer number of database groups each with IPaddr, postgres and LVM resources. In that case, does it mean that 3 web server groups are weighted the same as 2 database groups in terms of distribution? Ilia > On Feb 17, 2017, at 2:58 AM, Kristoffer Grönlund <deceive...@gmail.com> wrote: > > Ilia Sokolinski <i...@clearskydata.com> writes: > >> Suppose I have a N node cluster where N > 2 running m*N resources. Resources >> don’t have preferred nodes, but since resources take RAM and CPU it is >> important to distribute them equally among the nodes. >> Will pacemaker do the equal distribution, e.g. m resources per node? >> If a node fails, will pacemaker redistribute the resources equally too, e.g. >> m * N/(N-1) per node? >> >> I don’t see any settings controlling this behavior in the documentation, but >> perhaps, pacemaker tries to be “fair” by default. >> > > Yes, pacemaker tries to allocate resources evenly by default, and will > move resources when nodes fail in order to maintain that. > > There are several different mechanisms that influence this behaviour: > > * Any placement constraints in general influence where resources are > allocated. > > * You can set resource-stickiness to a non-zero value which determines > to which degree Pacemaker prefers to leave resources running where > they are. The score is in relation to other placement scores, like > constraint scores etc. This can be set for individual resources or > globally. [1] > > * If you have an asymmetrical cluster, resources have to be manually > allocated to nodes via constraints, see [2] > > [1]: > http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Pacemaker_Explained/index.html#s-resource-options > [2]: > http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Pacemaker_Explained/index.html#_asymmetrical_opt_in_clusters > > Cheers, > Kristoffer > >> Thanks >> >> Ilia Sokolinski >> _______________________________________________ >> Users mailing list: Users@clusterlabs.org >> http://lists.clusterlabs.org/mailman/listinfo/users >> >> Project Home: http://www.clusterlabs.org >> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf >> Bugs: http://bugs.clusterlabs.org > > -- > // Kristoffer Grönlund > // kgronl...@suse.com _______________________________________________ Users mailing list: Users@clusterlabs.org http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
