On Mon, Dec 20, 2010 at 10:48 PM, Andrew Beekhof <and...@beekhof.net> wrote:
> > > On Mon, Dec 20, 2010 at 10:25 PM, Patrick H. <pacema...@feystorm.net>wrote: > >> Sent: Sat Nov 13 2010 04:20:56 GMT-0700 (Mountain Standard Time) >> From: Andrew Beekhof <and...@beekhof.net> <and...@beekhof.net> >> To: The Pacemaker cluster resource manager >> <pacemaker@oss.clusterlabs.org> <pacemaker@oss.clusterlabs.org> >> Subject: Re: [Pacemaker] symmetric anti-collocation >> >> On Fri, Nov 12, 2010 at 5:27 PM, Alan Jones <falanclus...@gmail.com> >> <falanclus...@gmail.com> wrote: >> >> >> On Thu, Nov 11, 2010 at 11:31 PM, Andrew Beekhof <and...@beekhof.net> >> <and...@beekhof.net> wrote: >> >> >> colocation X-Y -2: X Y >> colocation Y-X -2: Y X >> >> >> the second one is implied by the first and is therefore redundant >> >> >> If only that were true! >> >> >> It is. I know exactly how my code works in this regard. >> More than likely a score of -2 is simply too low to have any effect. >> >> >> I'm going to have to side with Alan here, his pasted statements are *NOT* >> redundant and also do *NOT* work. Please be a little more accepting that >> your code might have problems. >> > > I think the past 7 years have adequately shown that I am under no illusions > on that score. > > However I actually know how colocation is supposed to work, and I'm and > telling you with 100% certainty that the second one is redundant. That the > combination doesn't do what you want is another story. > > Unless you use a clone in some manner, there is no way to express: > > If nodeA fails, stop rscA > If nodeB fails, stop rscB > "Unless you use scores of -INFINITY" It is very clearly documented that scores other than +/-INFINITY are _hints_ to the PE and may be ignored. > > In order to complete computations before the end of the universe, Pacemaker > requires you to decide with of rscA and rscB is more important and will > sacrifice the other. > > You can of course argue that this requirement is a crime against humanity, > but it remains how Pacemaker is currently designed to work. > > >> Exhibit A: >> crm(live)# configure show >> node nas01 \ >> attributes standby="off" >> node nas02 \ >> attributes standby="off" >> node nas03 \ >> attributes standby="on" >> primitive d1 ocf:pacemaker:Dummy >> primitive d2 ocf:pacemaker:Dummy >> colocation co1 -inf: d1 d2 >> colocation co2 -inf: d2 d1 >> property $id="cib-bootstrap-options" \ >> dc-version="1.0.10-da7075976b5ff0bee71074385f8fd02f296ec8a3" \ >> cluster-infrastructure="openais" \ >> expected-quorum-votes="3" \ >> stonith-enabled="false" \ >> default-resource-stickiness="INFINITY" >> >> >> >> >> crm(live)# status >> ============ >> Last updated: Mon Dec 20 21:03:49 2010 >> Stack: openais >> Current DC: nas01 - partition with quorum >> Version: 1.0.10-da7075976b5ff0bee71074385f8fd02f296ec8a3 >> 3 Nodes configured, 3 expected votes >> 2 Resources configured. >> ============ >> >> Node nas03: standby >> Online: [ nas01 nas02 ] >> >> d1 (ocf::pacemaker:Dummy): Started nas01 >> d2 (ocf::pacemaker:Dummy): Started nas02 >> >> >> >> >> crm(live)# node standby nas02 >> crm(live)# status >> ============ >> Last updated: Mon Dec 20 21:04:14 2010 >> Stack: openais >> Current DC: nas01 - partition with quorum >> Version: 1.0.10-da7075976b5ff0bee71074385f8fd02f296ec8a3 >> 3 Nodes configured, 3 expected votes >> 2 Resources configured. >> ============ >> >> Node nas02: standby >> Node nas03: standby >> Online: [ nas01 ] >> >> d2 (ocf::pacemaker:Dummy): Started nas01 >> >> Notice how resource 'd1' got evicted from node 'nas01' and 'd2' replaced >> it. This would indicate that the 'co2' rule is being completely ignored. In >> fact if you delete the co2 rule, you get the exact same behavior. If you >> were to delete the co1 rule, and put 'nas02' in standby, d1 would have >> stayed running on 'nas01' instead of being replaced. This would indicate >> that the constraints are NOT redundant and NOT implied by eachother. >> >> I'm not trying to be disrespectful or rude, its just that nobody is >> perfect. >> >> _______________________________________________ >> 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
