So, changing this from a mind-experiment to a real experiment I set up a simple cluster. pacemaker 1.1.10 cman 3.1.7 corosync 1.4.6 There are 2 nodes. No utilization attributes are defined for the nodes. There are 3 resources. There are no capacities defined for the resources. These are simple 'Dummy' resources. When the resources are created I see them allocated to node1, node2, and then node1. However, when I restart a node, the resources will always be allocated to a single node - the node that was not restarted. The node that restarts does not get any resources allocated to it. If I restart both nodes at about the same time, I see resources allocated to both nodes. If I restart a resource, I see it allocated to the node with the fewest resources. Good. This is the behavior I expected to see. I would like to know of a strategy to get resources 'rebalanced' when a node restarts so that all the nodes have resources. Is this possible? I know that it might not be good to have resources automatically move. The interruption of a resource probably isn't desirable. But, if I wanted to do it, could I? Regards. Mark K Vallevand Mark.Vallevand@xxxxxxxxxx <mailto:Mark.Vallevand@xxxxxxxxxx> Never try and teach a pig to sing: it's a waste of time, and it annoys the pig. THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. -----Original Message----- From: Vallevand, Mark K Sent: Thursday, October 01, 2015 12:17 PM To: 'misch@xxxxxxxxxxxxxxxxx'; linux clustering Subject: RE: Resource placement after node comes online. Thank you. As a mind-experiment, consider this very simple example. Is my understanding correct? 3 node cluster. All node equal with capacity 10. Total cluster capacity 30. 15 resources. All equal with utilization 1. All nodes are off. Node1 turns on. Joins cluster. 10 resources start. Some time later, node2 turns on. Joins cluster. 5 resources start. Resources are distributed how? 10 on node1 and 5 on node2? Will some resources migrate to node2? And even later, node3 turns on. Joins cluster. No more resources start. Resources are distributed how? 10 on node1 and 5 on node2 and 0 on node3? Or will some resources migrate to node3? Our clustering has been very successful to this point. We are considering future options. Regards. Mark K Vallevand Mark.Vallevand@xxxxxxxxxx <mailto:Mark.Vallevand@xxxxxxxxxx> Never try and teach a pig to sing: it's a waste of time, and it annoys the pig. THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. -----Original Message----- From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster-bounces@xxxxxxxxxx] On Behalf Of Michael Schwartzkopff Sent: Thursday, October 01, 2015 11:40 AM To: linux clustering Subject: Re: Resource placement after node comes online. Am Donnerstag, 1. Oktober 2015, 16:25:48 schrieb Vallevand, Mark K: > In a multiple node cluster with resources distributed across the nodes, is > there a way to automatically 'rebalance' resources when a node comes > online? pacemaker decides where to stop / start resources based on a score system every time the cluster receives an event. A node joing the cluster is definitely an event that triggers a recalculation of the scores that a resource would collect on every node. Baed on constraints you can configure your cluster to re-distribute resources in a very granular way. -- Dr. Michael Schwartzkopff Guardinistr. 63 81375 München Tel: (0162) 1650044 Fax: (089) 620 304 13 -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
