On Sun, May 06, 2012 at 09:45:09PM +1000, Andrew Beekhof wrote: > On Thu, May 3, 2012 at 5:38 PM, Lars Ellenberg > <lars.ellenb...@linbit.com> wrote: > > > > People sometimes think they have a use case > > for influencing which node will be the DC. > > Agreed :-) > > > > > Sometimes it is latency (certain cli commands work faster > > when done on the DC), > > Config changes can be run against any node, there is no reason to go > to the one on the DC. > > > sometimes they add a "mostly quorum" > > node which may be not quite up to the task of being DC. > > I'm not sure I buy that. Most of the load would comes from the > resources themselves. > > > Prohibiting a node from becoming DC completely would > > mean it can not even be cleanly shutdown (with 1.0.x, no MCP), > > or act on its own resources for certain no-quorum policies. > > > > So here is a patch I have been asked to present for discussion, > > May one ask where it originated? > > > against Pacemaker 1.0, that introduces a "dc-prio" configuration > > parameter, which will add some skew to the election algorithm. > > > > > > Open questions: > > * does it make sense at all? > > Doubtful :-) > > > > > * election algorithm compatibility, stability: > > will the election be correct if some nodes have this patch, > > and some don't ? > > Unlikely, but you could easily make it so by placing it after the > version check (and bumping said version in the patch) > > > * How can it be improved so that a node with dc-prio=0 will > > "give up" its DC-role as soon as there is at least one other node > > with dc-prio > 0? > > Short of causing an election every time a node joins... I doubt it.
Where would be a suitable place in the code/fsa to do so? Thanks, -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com _______________________________________________ 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://bugs.clusterlabs.org
