Comment 0 for bug 1405588

root@juju-xh-machine-5:~# dpkg -l|grep openvswitch
ii openvswitch-common 2.0.2-0ubuntu0.14.04.1 amd64 Open vSwitch common components
ii openvswitch-switch 2.0.2-0ubuntu0.14.04.1 amd64 Open vSwitch switch implementations

root@juju-xh-machine-5:~# uname -a
Linux juju-precise-machine-5 3.13.0-43-generic #72-Ubuntu SMP Mon Dec 8 19:35:06 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

root@juju-xh-machine-5:~# cat /etc/issue
Ubuntu 14.04.1 LTS \n \l

root@juju-xh-machine-5:~# ovs-vsctl show
2014-12-25T09:26:56Z|00001|reconnect|WARN|unix:/var/run/openvswitch/db.sock: connection attempt failed (Protocol error)
ovs-vsctl: unix:/var/run/openvswitch/db.sock: database connection failed (Protocol error)

workaround:
restart openvswitch-switch

But ovs-vsctl will get this error every several minutes.