Deployment guide of Resource Agent

How to deploy Resource Agent of DataSource Node. This guide only
has configuration steps for Resource Agent with Pacemaker.

Closes-Bug: #1602853
Partially implements blueprint: high-availability-design

Change-Id: Ic7cc95396472e6c13724b196c34aae66718eb939

doc/source/ha-deployment.rst

@@ -0,0 +1,101 @@
+.. include:: aliases.rst
+
+.. _ha_deployment:
+
+
+=============
+HA deployment
+=============
+
+Overview
+--------
+
+This section shows how to deploy Congress with High Availability (HA).
+Congress is divided to 2 parts in HA. First part is API and PolicyEngine
+Node which is replicated with Active-Active style. Another part is
+DataSource Node which is deployed with warm-stanby style.
+
+.. code-block:: text
+
+  +-------------------------------------+      +--------------+
+  |       Load Balancer (eg. HAProxy)   | <----+ Push client  |
+  +----+-------------+-------------+----+      +--------------+
+       |             |             |
+  PE   |        PE   |        PE   |        all+DSDs node
+  +---------+   +---------+   +---------+   +-----------------+
+  | +-----+ |   | +-----+ |   | +-----+ |   | +-----+ +-----+ |
+  | | API | |   | | API | |   | | API | |   | | DSD | | DSD | |
+  | +-----+ |   | +-----+ |   | +-----+ |   | +-----+ +-----+ |
+  | +-----+ |   | +-----+ |   | +-----+ |   | +-----+ +-----+ |
+  | | PE  | |   | | PE  | |   | | PE  | |   | | DSD | | DSD | |
+  | +-----+ |   | +-----+ |   | +-----+ |   | +-----+ +-----+ |
+  +---------+   +---------+   +---------+   +--------+--------+
+       |             |             |                 |
+       |             |             |                 |
+       +--+----------+-------------+--------+--------+
+          |                                 |
+          |                                 |
+  +-------+----+   +------------------------+-----------------+
+  |  Oslo Msg  |   | DBs (policy, config, push data, exec log)|
+  +------------+   +------------------------------------------+
+
+
+HA for API and Policy Engine Node
+---------------------------------
+
+Please write down how to deploy API and/or PolicyEngine Node.
+
+HA for DataSource Node
+-----------------------
+
+Nodes which DataSourceDriver runs on takes warm-standby style. Congress assumes
+cluster manager handles the active-standby cluster. In this document, we describe
+how to make HA of DataSourceDriver node by `Pacemaker`_ .
+
+See the `OpenStack High Availability Guide`__ for general usage of Pacemaker
+and how to deploy Pacemaker cluster stack. The guide has some HA configuration
+for other OpenStack projects.
+
+__ http://docs.openstack.org/ha-guide/index.html
+.. _Pacemaker: http://clusterlabs.org/
+
+Prepare OCF resource agent
+==========================
+
+You need a custom Resource Agent (RA) for DataSoure Node HA. The custom RA is
+located in Congress repository, ``/path/to/congress/script/ocf/congress-datasource``.
+Install the RA with following steps.
+
+.. code-block:: sh
+
+  $ cd /usr/lib/ocf/resource.d
+  $ mkdir openstack
+  $ cd openstack
+  $ cp /path/to/congress/script/ocf/congress-datasource ./congress-datasource
+  $ chmod a+rx congress-datasource
+
+Configure RA
+============
+
+You can now add the Pacemaker configuration for Congress DataSource Node resource.
+Connect to the Pacemaker cluster with the *crm configure* command and add the
+following cluster resources. After adding the resource make sure *commit*
+the change.
+
+.. code-block:: sh
+
+  primitive ds-node ocf:openstack:congress-datasource \
+     params config="/etc/congress/congress.conf" \
+     node_id="datasource-node" \
+     op monitor interval="30s" timeout="30s"
+
+Make sure that all nodes in the cluster have same config file with same name and
+path since DataSource Node resource, ``ds-node``, uses config file defined at
+*config* parameter to launch the resource.
+
+The RA has following configurable parameters.
+
+* config: a path of Congress's config file
+* node_id(Option): a node id of the datasource node. Default is "datasource-node".
+* binary(Option): a path of Congress binary Default is "/usr/local/bin/congress-server".
+* additional_parameters(Option): additional parameters of congress-server

doc/source/index.rst

@@ -19,6 +19,7 @@ Contents:
    enforcement
    api
    config
+   ha-deployment
 
    contributing
    codeoverview