Merge "Add ceph-pool-weight option for calculating pgs"

.gitignore

@@ -10,3 +10,4 @@ xenial/
 precise/
 tests/cirros-*-disk.img
 .unit-state.db
+.idea

config.yaml

@@ -268,6 +268,21 @@ options:
       rbd pool has been created, changing this value will not have any
       effect (although it can be changed in ceph by manually configuring
       your ceph cluster).
+  ceph-pool-weight:
+    type: int
+    default: 30
+    description: |
+      Defines a relative weighting of the pool as a percentage of the total
+      amount of data in the Ceph cluster. This effectively weights the number
+      of placement groups for the pool created to be appropriately portioned
+      to the amount of data expected. For example, if the ephemeral volumes
+      for the OpenStack compute instances are expected to take up 20% of the
+      overall configuration then this value would be specified as 20. Note -
+      it is important to choose an appropriate value for the pool weight as
+      this directly affects the number of placement groups which will be
+      created for the pool. The number of placement groups for a pool can
+      only be increased, never decreased - so it is important to identify the
+      percent of data that will likely reside in the pool.
   # Other configuration options
   sysctl:
     type: string

hooks/nova_compute_hooks.py

@@ -332,8 +332,10 @@ def ceph_joined():
 
 def get_ceph_request():
     rq = CephBrokerRq()
+    name = config('rbd-pool')
     replicas = config('ceph-osd-replication-count')
-    rq.add_op_create_pool(name=config('rbd-pool'), replica_count=replicas)
+    weight = config('ceph-pool-weight')
+    rq.add_op_create_pool(name=name, replica_count=replicas, weight=weight)
     return rq
 
 

unit_tests/test_nova_compute_hooks.py

@@ -500,6 +500,15 @@ class NovaComputeRelationsTests(CharmTestCase):
         self.assertEquals(ex, configs.write.call_args_list)
         self.service_restart.assert_called_with('nova-compute')
 
+    @patch('charmhelpers.contrib.storage.linux.ceph.CephBrokerRq'
+           '.add_op_create_pool')
+    def test_get_ceph_request(self, mock_add_op):
+        self.test_config.set('rbd-pool', 'nova')
+        self.test_config.set('ceph-osd-replication-count', 3)
+        self.test_config.set('ceph-pool-weight', 28)
+        hooks.get_ceph_request()
+        mock_add_op.assert_called_with(name='nova', replica_count=3, weight=28)
+
     @patch.object(hooks, 'CONFIGS')
     def test_neutron_plugin_changed(self, configs):
         self.nova_metadata_requirement.return_value = (True,