The requirement for 3 Controller Nodes comes from the use of MySQL Galera Clustering, it requires a minimum of 3 nodes to minimize split brain. Tho, there is a way to run it with two, where you run a service to act as a third voting member of the cluster, just would not contain or respond to any sql queries. On Wed, Apr 9, 2014 at 10:11 AM, Alexandre De Carvalho < alexandre7.decarvalho at gmail.com> wrote: > Hi, > > I don't understand why we need 3 Controllers Nodes to do HA. > > It's not possible to do that with 2 Controllers Nodes ? > > > Thanks > > -- > Best regards, > Alexandre > > > > _______________________________________________ > Mailing list: > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack > Post to : openstack at lists.openstack.org > Unsubscribe : > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack/attachments/20140409/1578bd0d/attachment.html>