I have an overcloud with 3 controller nodes, everything is working fine, the problem is when I reboot one of the controllers. When the node comes online, all the services (nova-api, neutron-server) on the other nodes are also restarted, causing a couple of minutes of downtime until everything is recovered.
In the example below I restarted controller2 and I see these messages on controller0. My question is if this is the expected behavior, because in my opinion it shouldn't happen.
Authorization Failed: Service Unavailable (HTTP 503)
== Glance images ==
Service Unavailable (HTTP 503)
== Nova managed services ==
No handlers could be found for logger "keystoneauth.identity.generic.base"
ERROR (ServiceUnavailable): Service Unavailable (HTTP 503)
== Nova networks ==
No handlers could be found for logger "keystoneauth.identity.generic.base"
ERROR (ServiceUnavailable): Service Unavailable (HTTP 503)
== Nova instance flavors ==
No handlers could be found for logger "keystoneauth.identity.generic.base"
ERROR (ServiceUnavailable): Service Unavailable (HTTP 503)
== Nova instances ==
No handlers could be found for logger "keystoneauth.identity.generic.base"
ERROR (ServiceUnavailable): Service Unavailable (HTTP 503)
[root@overcloud-controller-0 ~]# openstack-status
Broadcast message from systemd-journald@overcloud-controller-0.localdomain (Thu 2016-08-04 09:22:31 UTC):
haproxy[2816]: proxy neutron has no server available!