Merge "add strategy doc:storage capacity balance"

doc/source/strategies/storage_capacity_balance.rst

@@ -0,0 +1,87 @@
+========================
+Storage capacity balance
+========================
+
+Synopsis
+--------
+
+**display name**: ``Storage Capacity Balance Strategy``
+
+**goal**: ``workload_balancing``
+
+    .. watcher-term:: watcher.decision_engine.strategy.strategies.storage_capacity_balance.StorageCapacityBalance
+
+Requirements
+------------
+
+Metrics
+*******
+
+None
+
+Cluster data model
+******************
+
+Storage cluster data model is required:
+
+    .. watcher-term:: watcher.decision_engine.model.collector.cinder.CinderClusterDataModelCollector
+
+Actions
+*******
+
+Default Watcher's actions:
+
+    .. list-table::
+       :widths: 25 35
+       :header-rows: 1
+
+       * - action
+         - description
+       * - ``volume_migrate``
+         - .. watcher-term:: watcher.applier.actions.volume_migration.VolumeMigrate
+
+Planner
+*******
+
+Default Watcher's planner:
+
+    .. watcher-term:: watcher.decision_engine.planner.weight.WeightPlanner
+
+Configuration
+-------------
+
+Strategy parameter is:
+
+==================== ====== ============= =====================================
+parameter            type   default       Value description
+==================== ====== ============= =====================================
+``volume_threshold`` Number 80.0          Volume threshold for capacity balance
+==================== ====== ============= =====================================
+
+
+Efficacy Indicator
+------------------
+
+None
+
+Algorithm
+---------
+
+For more information on the zone migration strategy please refer to:
+http://specs.openstack.org/openstack/watcher-specs/specs/queens/implemented/storage-capacity-balance.html
+
+How to use it ?
+---------------
+
+.. code-block:: shell
+
+    $ openstack optimize audittemplate create \
+      at1 workload_balancing --strategy storage_capacity_balance
+
+    $ openstack optimize audit create -a at1 \
+      -p volume_threshold=85.0
+
+External Links
+--------------
+
+None