Bridge Interface shown down in Horizon Dashboard @ Openstack

sudo ovs-vsctl br-get-external-id br-ex returns nothing, and so br-ex is excluded from the list of ancillary bridges and so the gateway port always shows as DOWN.
A workaround is to set the bridge-id to br-ex and restart the L2 agent:

ovs-vsctl br-set-external-id br-ex bridge-id br-ex
ovs-vsctl br-set-external-id br-ex-2 bridge-id br-ex-2

Changing qpidd to rabbitmq for Openstack

Stopping qpidd on all server

service qpidd stop

chkconfig qpidd off

Installing packages

yum install ntp rabbitmq-server

Configuring Cluster

On Controller1

yum install ntp rabbitmq-server

chown rabbitmq:rabbitmq /var/lib/rabbitmq/*

chown rabbitmq:rabbitmq /var/lib/rabbitmq/.erlang.cookie

/etc/init.d/rabbitmq-server restart

scp /var/lib/rabbitmq/.erlang.cookie root@controller2:/var/lib/rabbitmq/

On Controller2

yum install ntp rabbitmq-server

yum install ntp rabbitmq-server

rabbitmqctl stop_app

rabbitmqctl join_cluster rabbit@controller1

rabbitmqctl start_app

rabbitmqctl cluster_status

Edit the configuration Files

Comment out the Qpidd entries In all the configuration and enter the below details. As Rabbitmq is default message broker other entries are not needed.

rabbit_host = controller

In Both the controller set the rabbitmq policy as below

rabbitmqctl set_policy HA '^(?!amq\.).*' '{"ha-mode": "all"}'

Configure HA using Corosync and pacemaker

Opening needed Ports in Iptables if We are using IPtables
/etc/sysconfig/iptables. Towards the end of the file, but before any REJECT statements, we add the following lines:
-A INPUT -p udp -m state --state NEW -m multiport --dports 5404,5405 -j ACCEPT
-A INPUT -m tcp -p tcp --dport 7788 -j ACCEPT
-A INPUT -m tcp -p tcp --dport 3306 -j ACCEPT

Installing modules
yum -y install wget
rpm -Uvh http://elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm
yum -y install drbd84-utils kmod-drbd84 --enablerepo=elrepo
yum -y install pacemaker corosync cluster-glue

wget -P /etc/yum.repos.d/ http://download.opensuse.org/repositories/network:/ha-clustering:/Stable/CentOS_CentOS-6/network:ha-clustering:Stable.repo
yum install crmsh

Configure Corosync 

vi /etc/corosync/corosync.conf
totem {
version: 2
secauth: off
threads: 0
interface {
ringnumber: 0
bindnetaddr: 10.0.0.0
mcastaddr: 226.94.1.1
mcastport: 5405
ttl: 1
}
}

logging {
fileline: off
to_stderr: no
to_logfile: yes
to_syslog: yes
logfile: /var/log/cluster/corosync.log
debug: off
timestamp: on
logger_subsys {
subsys: AMF
debug: off
}
}

amf {
mode: disabled
}

service {
        # Load the Pacemaker Cluster Resource Manager
        ver:       1
        name:      pacemaker
}

aisexec {
        user:   root
        group:  root
}


chkconfig --level 3 corosync on
service corosync start
chkconfig --level 3 pacemaker on
service pacemaker start

Checking the Cluster Connectivity
corosync-objctl runtime.totem.pg.mrp.srp.members

Check the service and cluster status
crm_mon -1


Configuring the cluster
>>crm configure
property no-quorum-policy="ignore" pe-warn-series-max="1000" pe-input-series-max="1000" pe-error-series-max="1000" cluster-recheck-interval="5min"
property stonith-enabled=false
commit

Adding a Cluster server for common IP (VIP)
>>crm configure
primitive p_api-ip ocf:heartbeat:IPaddr2 params ip="10.0.0.199" cidr_netmask="24" op monitor interval="30s"
commit

Now we need to configure the needed services in the CRM.