
HA stability and scalability improvements
-----------------------------------------

Mirantis OpenStack 6.0 includes a number of internal enhancements to improve
the stability and scalability of the deployed environment:

* The :ref:`Pacemaker<pacemaker-term>` deployment configuration has been
  improved to support a larger number of OpenStack Controller nodes.

* :ref:`Corosync<corosync-term>` cluster communication framework was updated to
  version 2.0.

* Installation of Pacemaker and Corosync is now a discrete stage of deployment.

* Debug handling of OCF scripts is now unified, OCF resources have been renamed
  and no longer include the "__old" string. Previously, debugging OCF scripts
  required significant manual intervention by the cloud operator.

* The OCF service provider has been refactored to disable creating the same
  service under systemd/upstart/sysvinit.

* Diff operations against Corosync CIB can now save data to memory rather than
  a file, speeding up the shutting down of Corosync services.

* Monit is now used in conjunction with Pacemaker to monitor and automatically
  repair critical services on OpenStack Compute nodes.

* If the public NIC on the primary controller becomes unavailable,
  the public VIP now migrates to another controller.



HA stability and scalability improvements
-----------------------------------------

Mirantis OpenStack 6.0 includes a number of internal enhancements to improve
the stability and scalability of the deployed environment:

* The :ref:`Pacemaker<pacemaker-term>` deployment configuration has been
  improved to support a larger number of OpenStack Controller nodes.

* Debug handling of OCF scripts is now unified, OCF resources have been renamed
  and no longer include the "__old" string. Previously, debugging OCF scripts
  required significant manual intervention by the cloud operator.

* Pacemaker service provider has been refactored to disable creating the
  same service under systemd/upstart/sysvinit.

* Idempotency was fixed in Pacemaker provider. Puppet will not create
  duplicate objects in Corosync CIB anymore.

* Pacemaker provider doesn't use 'crm' or 'pcs' tools anymore. All operations
  are performed using native corosync tools. This allows to use provider with
  CentOS 7 and Ubuntu 14.04 as well as the currently supported OSes.

* OCF scripts were improved to cover more complex HA scenarios.

* If the public NIC on the primary controller becomes unavailable,
  the public VIP now migrates to another controller.

Add the actual tasks from HA blueprint
Add the actual tasks from HA blueprint

Change-Id: I263b329532c95f0aeefba6365716223e74c73bc8
Signed-off-by: Sergii Golovatiuk <98168b9e97e341cddc0074e7bec42876c0bd6617@mirantis.com>
