|author||Dan Radez <email@example.com>||2016-09-20 15:25:56 -0400|
|committer||Dan Radez <firstname.lastname@example.org>||2016-09-20 16:39:19 -0400|
diff --git a/docs/installationprocedure/architecture.rst b/docs/installationprocedure/architecture.rst
index c63da27..f1861d0 100644
@@ -23,6 +23,64 @@ The overcloud is OPNFV. Configuration will be passed into undercloud and
the undercloud will use OpenStack's orchestration component, named Heat, to
execute a deployment that will provision the target OPNFV nodes.
+Apex High Availability Architecture
+The undercloud is not Highly Available. End users do not depend on the
+underloud. It is only for management purposes.
+Apex will deploy three control nodes in an HA deployment. Each of these nodes
+will run the following services:
+- Stateless OpenStack services
+- MariaDB / Galera
+- HA Proxy
+- Pacemaker & VIPs
+Stateless OpenStack services
+ All running statesless OpenStack services are load balanced by HA Proxy.
+ Pacemaker monitors the services and ensures that they are running.
+Stateful OpenStack services
+ All running stateful OpenStack services are load balanced by HA Proxy.
+ They are monitored by pacemaker in an active/passive failover configuration.
+MariaDB / Galera
+ The MariaDB database is replicated across the control nodes using Galera.
+ Pacemaker is responsible for a proper start up of the Galera cluster. HA
+ Proxy provides and active/passive failover methodology to connections to the
+ The message bus is managed by Pacemaker to ensure proper start up and
+ establishment of clustering across cluster members.
+ OpenDaylight is currently installed on all three control nodes but only
+ started on the first control node. OpenDaylight's HA capabilities are not yet
+ mature enough to be enabled.
+ HA Proxy is monitored by Pacemaker to ensure it is running across all nodes
+ and available to balance connections.
+Pacemaker & VIPs
+ Pacemaker has relationships and restraints setup to ensure proper service
+ start up order and Virtual IPs associated with specific services are running
+ on the proper host.
+VM Migration is configured and VMs can be evacuated as needed or as invoked
+by tools such as heat as part of a monitored stack deployment in the overcloud.
OPNFV Scenario Architecture