diff --git a/ceilometer/storage/__init__.py b/ceilometer/storage/__init__.py
index 728cc1780..8465893ea 100644
--- a/ceilometer/storage/__init__.py
+++ b/ceilometer/storage/__init__.py
@@ -63,6 +63,11 @@ class StorageBadVersion(Exception):
     """Error raised when the storage backend version is not good enough."""
 
 
+class StorageBadAggregate(Exception):
+    """Error raised when an aggregate is unacceptable to storage backend."""
+    code = 400
+
+
 def get_engine(conf):
     """Load the configured engine and return an instance."""
     if conf.database_connection:
diff --git a/ceilometer/storage/impl_mongodb.py b/ceilometer/storage/impl_mongodb.py
index 365bc367e..0c6958a21 100644
--- a/ceilometer/storage/impl_mongodb.py
+++ b/ceilometer/storage/impl_mongodb.py
@@ -144,6 +144,90 @@ class Connection(pymongo_base.Connection):
         ),
     )
 
+    UNPARAMETERIZED_AGGREGATES = dict(
+        emit_initial=dict(
+            stddev=(
+                ''
+            )
+        ),
+        emit_body=dict(
+            stddev='sdsum: this.counter_volume,'
+                   'sdcount: 1,'
+                   'weighted_distances: 0,'
+                   'stddev: 0,'
+        ),
+        reduce_initial=dict(
+            stddev=''
+        ),
+        reduce_body=dict(
+            stddev='sdsum: values[0].sdsum,'
+                   'sdcount: values[0].sdcount,'
+                   'weighted_distances: values[0].weighted_distances,'
+                   'stddev: values[0].stddev,'
+        ),
+        reduce_computation=dict(
+            stddev=(
+                'var deviance = (res.sdsum / res.sdcount) - values[i].sdsum;'
+                'var weight = res.sdcount / ++res.sdcount;'
+                'res.weighted_distances += (Math.pow(deviance, 2) * weight);'
+                'res.sdsum += values[i].sdsum;'
+            )
+        ),
+        finalize=dict(
+            stddev=(
+                'value.stddev = Math.sqrt(value.weighted_distances /'
+                '  value.sdcount);'
+            )
+        ),
+    )
+
+    PARAMETERIZED_AGGREGATES = dict(
+        validate=dict(
+            cardinality=lambda p: p in ['resource_id', 'user_id', 'project_id',
+                                        'source']
+        ),
+        emit_initial=dict(
+            cardinality=(
+                'var aggregate = {};'
+                'aggregate["cardinality/%(aggregate_param)s"] ='
+                '  this["%(aggregate_param)s"];'
+            )
+        ),
+        emit_body=dict(
+            cardinality='aggregate : aggregate,'
+        ),
+        reduce_initial=dict(
+            cardinality=(
+                'var distincts = {};'
+                'distincts[values[0].aggregate['
+                '  "cardinality/%(aggregate_param)s"]] = true;'
+                'var aggregate = {};'
+                'aggregate["cardinality/%(aggregate_param)s"] = NumberInt(1);'
+            )
+        ),
+        reduce_body=dict(
+            cardinality='aggregate : aggregate,'
+        ),
+        reduce_computation=dict(
+            cardinality=(
+                'if (!(values[i].aggregate["cardinality/%(aggregate_param)s"]'
+                '    in distincts)) {'
+                '  distincts[values[i].aggregate['
+                '    "cardinality/%(aggregate_param)s"]] = true;'
+                '  res.aggregate["cardinality/%(aggregate_param)s"] ='
+                '    NumberInt(Object.keys(distincts).length);}'
+            )
+        ),
+        finalize=dict(
+            cardinality=(
+                'if (typeof value.aggregate['
+                '    "cardinality/%(aggregate_param)s"] !== "number") {'
+                '  value.aggregate["cardinality/%(aggregate_param)s"] ='
+                '     NumberInt(1);}'
+            )
+        ),
+    )
+
     EMIT_STATS_COMMON = """
         %(aggregate_initial_placeholder)s
         emit(%(key_val)s, { unit: this.counter_unit,
@@ -651,8 +735,20 @@ class Connection(pymongo_base.Connection):
         fragments = ''
 
         for a in aggregate:
-            if a.func in fragment_map:
+            if a.func in self.STANDARD_AGGREGATES[fragment_key]:
+                fragment_map = self.STANDARD_AGGREGATES[fragment_key]
                 fragments += fragment_map[a.func]
+            elif a.func in self.UNPARAMETERIZED_AGGREGATES[fragment_key]:
+                fragment_map = self.UNPARAMETERIZED_AGGREGATES[fragment_key]
+                fragments += fragment_map[a.func]
+            elif a.func in self.PARAMETERIZED_AGGREGATES[fragment_key]:
+                fragment_map = self.PARAMETERIZED_AGGREGATES[fragment_key]
+                v = self.PARAMETERIZED_AGGREGATES['validate'].get(a.func)
+                if not (v and v(a.param)):
+                    raise storage.StorageBadAggregate('Bad aggregate: %s.%s'
+                                                      % (a.func, a.param))
+                params = dict(aggregate_param=a.param)
+                fragments += (fragment_map[a.func] % params)
             else:
                 raise NotImplementedError(_('Selectable aggregate function %s'
                                             ' is not supported') % a.func)
@@ -732,16 +828,18 @@ class Connection(pymongo_base.Connection):
     @staticmethod
     def _stats_result_aggregates(result, aggregate):
         stats_args = {}
-        if isinstance(result.get('count'), (int, long)):
-            stats_args['count'] = int(result['count'])
-        for attr in ['min', 'max', 'sum', 'avg']:
+        for attr in ['count', 'min', 'max', 'sum', 'avg']:
             if attr in result:
                 stats_args[attr] = result[attr]
+
         if aggregate:
-            stats_args['aggregate'] = dict(
-                ('%s%s' % (a.func, '/%s' % a.param if a.param else ''),
-                 result[a.func]) for a in aggregate
-            )
+            stats_args['aggregate'] = {}
+            for a in aggregate:
+                ak = '%s%s' % (a.func, '/%s' % a.param if a.param else '')
+                if ak in result:
+                    stats_args['aggregate'][ak] = result[ak]
+                elif 'aggregate' in result:
+                    stats_args['aggregate'][ak] = result['aggregate'].get(ak)
         return stats_args
 
     @staticmethod
@@ -840,7 +938,9 @@ class Connection(pymongo_base.Connection):
                                                'min': True,
                                                'sum': True,
                                                'avg': True,
-                                               'count': True}}
+                                               'count': True,
+                                               'stddev': True,
+                                               'cardinality': True}}
                            },
             'alarms': {'query': {'simple': True,
                                  'complex': True},