Hi Andrew, all, I had an idea last night, that it may be worth implementing fully-dynamic cluster resize support in pacemaker, utilizing possibilities CMAP and votequorum provide.
Idea is to: * Do not add nodes from nodelist to CIB if their join-count in cmap is zero (but do not touch CIB nodes which exist in a nodelist and have zero join-count in cmap). * Install watches on a cmap nodelist.node and runtime.totem.pg.mrp.srp.members subtrees (cmap_track_add). * Add missing nodes to CIB as soon as they are both ** defined in a nodelist ** their join count becomes non-zero. * Remove nodes from CIB when they are removed from a nodelist. Certainly, this requires some CMAP values (especially votequorum ones and may be totem mode) to have some 'well-known' values, f.e. only UDPU mode and quorum.allow_downscale=1, that should be defined yet. May be, it also have sense to make this depend on some new CMAP variable, f.e. nodelist.dynamic=1. I would even try to implement this if general agreement is gained and nobody else wants to implement this. Can you please comment on this? Vladislav _______________________________________________ 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
