On Thursday 08 April 2021 at 16:55:47, Ken Gaillot wrote: > On Thu, 2021-04-08 at 14:32 +0000, Jason Long wrote: > > Why, when node1 is back, then web server still on node2? Why not > > switched? > > By default, there are no preferences as to where a resource should run. > The cluster is free to move or leave resources as needed. > > If you want a resource to prefer a particular node, you can use > location constraints to express that. However there is rarely a need to > do so; in most clusters, nodes are equally interchangeable.
I would add that it is generally preferable, in fact, to leave a resource where it is unless there's a good reason to move it. Imagine for example that you have three nodes and a resource is running on node A. Node A fails, the resource moves to node C, and node A then comes back again. If the resource then got moved back to node A just because it had recovered, you've now had two transitions of the resource (each of which means *some* downtime, however small that may be), whereas if it remains running on node C until such time as there's a good reason to move it away, you've only had one transition to cope with. Antony. -- "The future is already here. It's just not evenly distributed yet." - William Gibson Please reply to the list; please *don't* CC me. _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/