On Mon, Apr 4, 2011 at 2:43 PM, Holger Teutsch <holger.teut...@web.de> wrote: > On Mon, 2011-04-04 at 11:05 +0200, Andrew Beekhof wrote: >> On Sat, Mar 19, 2011 at 11:55 AM, Holger Teutsch <holger.teut...@web.de> >> wrote: >> > Hi Dejan, >> > >> > On Fri, 2011-03-18 at 14:24 +0100, Dejan Muhamedagic wrote: >> >> Hi, >> >> >> >> On Fri, Mar 18, 2011 at 12:21:40PM +0100, Holger Teutsch wrote: >> >> > Hi, >> >> > I would like to submit 2 patches of an initial implementation for >> >> > discussion. >> > .. >> >> > To recall: >> >> > >> >> > crm_resource --move resource >> >> > creates a "standby" rule that moves the resource off the currently >> >> > active node >> >> > >> >> > while >> >> > >> >> > crm_resource --move resource --node newnode >> >> > creates a "prefer" rule that moves the resource to the new node. >> >> > >> >> > When dealing with clones and masters the behavior was random as the code >> >> > only considers the node where the first instance of the clone was >> >> > started. >> >> > >> >> > The new code behaves consistently for the master role of an m/s >> >> > resource. The options "--master" and "rsc:master" are somewhat redundant >> >> > as a "slave" move is not supported. Currently it's more an >> >> > acknowledgement of the user. >> >> > >> >> > On the other hand it is desirable (and was requested several times on >> >> > the ML) to stop a single resource instance of a clone or master on a >> >> > specific node. >> >> > >> >> > Should that be implemented by something like >> >> > >> >> > "crm_resource --move-off --resource myresource --node devel2" ? >> >> > >> >> > or should >> >> > >> >> > crm_resource refuse to work on clones >> >> > >> >> > and/or should moving the master role be the default for m/s resources >> >> > and the "--master" option discarded ? >> >> >> >> I think that we also need to consider the case when clone-max is >> >> less than the number of nodes. If I understood correctly what you >> >> were saying. So, all of move slave and move master and move clone >> >> should be possible. >> >> >> > >> > I think the following use cases cover what can be done with such kind of >> > interface: >> > >> > crm_resource --moveoff --resource myresource --node mynode >> > -> all resource variants: check whether active on mynode, then create >> > standby constraint >> > >> > crm_resource --move --resource myresource >> > -> primitive/group: convert to --moveoff --node `current_node` >> > -> clone/master: refused >> > >> > crm_resource --move --resource myresource --node mynode >> > -> primitive/group: create prefer constraint >> > -> clone/master: refused >> >> Not sure this needs to be refused. > > I see the problem that the node where the resource instance should be > moved off had to be specified as well to get predictable behavior. > > Consider a a 2 way clone on a 3 node cluster. > If the clone is active on A and B what should > > crm_resource --move --resource myClone --node C > > do ?
I would expect it to create the +inf constraint for C but no contraint(s) for the current location(s) > This would require an additional --from-node or similar. > >> Other than that the proposal looks sane. >> >> My first thought was to make --move behave like --move-off if the >> resource is a clone or /ms, but since the semantics are the exact >> opposite, that might introduce introduce more problems than it solves. > > That was my perception as well. > >> >> Does the original crm_resource patch implement this? > > No, I will submit an updated version later this week. > > - holger > > > _______________________________________________ > 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://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker > _______________________________________________ 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://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker