On 10/16/2014 09:00 AM, Florian Haas wrote: > On Thu, Oct 16, 2014 at 1:59 PM, Russell Bryant <rbry...@redhat.com> wrote: >> On 10/16/2014 04:29 AM, Florian Haas wrote: >>>>>>> (5) Let monitoring and orchestration services deal with these use >>>>>>> cases and >>>>>>> have Nova simply provide the primitive API calls that it already does >>>>>>> (i.e. >>>>>>> host evacuate). >>>>>> >>>>>> That would arguably lead to an incredible amount of wheel reinvention >>>>>> for node failure detection, service failure detection, etc. etc. >>>>> >>>>> How so? (5) would use existing wheels for monitoring and orchestration >>>>> instead of writing all new code paths inside Nova to do the same thing. >>>> >>>> Right, there may be some confusion here ... I thought you were both >>>> agreeing that the use of an external toolset was a good approach for the >>>> problem, but Florian's last message makes that not so clear ... >>> >>> While one of us (Jay or me) speaking for the other and saying we agree >>> is a distributed consensus problem that dwarfs the complexity of >>> Paxos, *I* for my part do think that an "external" toolset (i.e. one >>> that lives outside the Nova codebase) is the better approach versus >>> duplicating the functionality of said toolset in Nova. >>> >>> I just believe that the toolset that should be used here is >>> Corosync/Pacemaker and not Ceilometer/Heat. And I believe the former >>> approach leads to *much* fewer necessary code changes *in* Nova than >>> the latter. >> >> Have you tried pacemaker_remote yet? It seems like a better choice for >> this particular case, as opposed to using corosync, due to the potential >> number of compute nodes. > > I'll assume that you are *not* referring to running Corosync/Pacemaker > on the compute nodes plus pacemaker_remote in the VMs, because doing > so would blow up the separation between the cloud operator and tenant > space.
Correct. > Running compute nodes as baremetal extensions of a different > Corosync/Pacemaker cluster (presumably the one that manages the other > Nova services) would potentially be an option, although vendors would > need to buy into this. Ubuntu, for example, currently only ships > pacemaker-remote in universe. Yes, this is what I had in mind. -- Russell Bryant _______________________________________________ OpenStack-dev mailing list OpenStackfirstname.lastname@example.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev