add support of batch recording metering data for mongodb

Add support of batch recording metering data to mongodb backend, since
the pymongo support *insert_many* interface which can be used to batch
record items, in "big-data" scenarios, this change can improve the
performance of metering data recording.

Change-Id: I9e1e61d5bb139349f7c2263fff8d230cb7096b5a

ceilometer/dispatcher/database.py

@@ -71,6 +71,8 @@ class DatabaseDispatcher(dispatcher.MeterDispatcherBase,
 
     def record_metering_data(self, data):
         # We may have receive only one counter on the wire
+        if not data:
+            return
         if not isinstance(data, list):
             data = [data]
 
@@ -82,18 +84,18 @@ class DatabaseDispatcher(dispatcher.MeterDispatcherBase,
                  'resource_id': meter['resource_id'],
                  'timestamp': meter.get('timestamp', 'NO TIMESTAMP'),
                  'counter_volume': meter['counter_volume']})
-            try:
-                # Convert the timestamp to a datetime instance.
-                # Storage engines are responsible for converting
-                # that value to something they can store.
-                if meter.get('timestamp'):
-                    ts = timeutils.parse_isotime(meter['timestamp'])
-                    meter['timestamp'] = timeutils.normalize_time(ts)
-                self.meter_conn.record_metering_data(meter)
-            except Exception as err:
-                LOG.error(_LE('Failed to record metering data: %s.'), err)
-                # raise the exception to propagate it up in the chain.
-                raise
+            # Convert the timestamp to a datetime instance.
+            # Storage engines are responsible for converting
+            # that value to something they can store.
+            if meter.get('timestamp'):
+                ts = timeutils.parse_isotime(meter['timestamp'])
+                meter['timestamp'] = timeutils.normalize_time(ts)
+        try:
+            self.meter_conn.record_metering_data_batch(data)
+        except Exception as err:
+            LOG.error(_LE('Failed to record %(len)s: %(err)s.'),
+                      {'len': len(data), 'err': err})
+            raise
 
     def record_events(self, events):
         if not isinstance(events, list):

ceilometer/storage/base.py

@@ -137,6 +137,11 @@ class Connection(object):
     def upgrade():
         """Migrate the database to `version` or the most recent version."""
 
+    def record_metering_data_batch(self, samples):
+        """Record the metering data in batch"""
+        for s in samples:
+            self.record_metering_data(s)
+
     @staticmethod
     def record_metering_data(data):
         """Write the data to the backend storage system.

ceilometer/storage/impl_mongodb.py

@@ -20,6 +20,9 @@
 # under the License.
 """MongoDB storage backend"""
 
+import itertools
+import operator
+
 import copy
 import datetime
 import uuid
@@ -243,69 +246,95 @@ class Connection(pymongo_base.Connection):
         self.conn.close()
 
     def record_metering_data(self, data):
-        """Write the data to the backend storage system.
+        # TODO(liusheng): this is a workaround that is because there are
+        # storage scenario tests which directly invoke this method and pass a
+        # sample dict with all the storage backends and
+        # call conn.record_metering_data. May all the Ceilometer
+        # native storage backends can support batch recording in future, and
+        # then we need to refactor the scenario tests.
+        self.record_metering_data_batch([data])
 
-        :param data: a dictionary such as returned by
-                     ceilometer.publisher.utils.meter_message_from_counter
+    def record_metering_data_batch(self, samples):
+        """Record the metering data in batch.
+
+        :param samples: a list of samples dict.
         """
         # Record the updated resource metadata - we use $setOnInsert to
         # unconditionally insert sample timestamps and resource metadata
         # (in the update case, this must be conditional on the sample not
         # being out-of-order)
-        data = copy.deepcopy(data)
-        data['resource_metadata'] = pymongo_utils.improve_keys(
-            data.pop('resource_metadata'))
-        resource = self.db.resource.find_one_and_update(
-            {'_id': data['resource_id']},
-            {'$set': {'project_id': data['project_id'],
-                      'user_id': data['user_id'],
-                      'source': data['source'],
-                      },
-             '$setOnInsert': {'metadata': data['resource_metadata'],
-                              'first_sample_timestamp': data['timestamp'],
-                              'last_sample_timestamp': data['timestamp'],
-                              },
-             '$addToSet': {'meter': {'counter_name': data['counter_name'],
-                                     'counter_type': data['counter_type'],
-                                     'counter_unit': data['counter_unit'],
-                                     },
-                           },
-             },
-            upsert=True,
-            return_document=pymongo.ReturnDocument.AFTER,
-        )
-
-        # only update last sample timestamp if actually later (the usual
-        # in-order case)
-        last_sample_timestamp = resource.get('last_sample_timestamp')
-        if (last_sample_timestamp is None or
-                last_sample_timestamp <= data['timestamp']):
-            self.db.resource.update_one(
-                {'_id': data['resource_id']},
-                {'$set': {'metadata': data['resource_metadata'],
-                          'last_sample_timestamp': data['timestamp']}}
+        sorted_samples = sorted(
+            copy.deepcopy(samples),
+            key=lambda s: (s['resource_id'], s['timestamp']))
+        res_grouped_samples = itertools.groupby(
+            sorted_samples, key=operator.itemgetter('resource_id'))
+        samples_to_update_resource = []
+        for resource_id, g_samples in res_grouped_samples:
+            g_samples = list(g_samples)
+            g_samples[-1]['meter'] = [{'counter_name': s['counter_name'],
+                                       'counter_type': s['counter_type'],
+                                       'counter_unit': s['counter_unit'],
+                                       } for s in g_samples]
+            g_samples[-1]['last_sample_timestamp'] = g_samples[-1]['timestamp']
+            g_samples[-1]['first_sample_timestamp'] = g_samples[0]['timestamp']
+            samples_to_update_resource.append(g_samples[-1])
+        for sample in samples_to_update_resource:
+            sample['resource_metadata'] = pymongo_utils.improve_keys(
+                sample.pop('resource_metadata'))
+            resource = self.db.resource.find_one_and_update(
+                {'_id': sample['resource_id']},
+                {'$set': {'project_id': sample['project_id'],
+                          'user_id': sample['user_id'],
+                          'source': sample['source'],
+                          },
+                 '$setOnInsert': {
+                     'metadata': sample['resource_metadata'],
+                     'first_sample_timestamp': sample['timestamp'],
+                     'last_sample_timestamp': sample['timestamp'],
+                    },
+                 '$addToSet': {
+                     'meter': {'$each': sample['meter']},
+                    },
+                 },
+                upsert=True,
+                return_document=pymongo.ReturnDocument.AFTER,
             )
 
-        # only update first sample timestamp if actually earlier (the unusual
-        # out-of-order case)
-        # NOTE: a null first sample timestamp is not updated as this indicates
-        # a pre-existing resource document dating from before we started
-        # recording these timestamps in the resource collection
-        first_sample_timestamp = resource.get('first_sample_timestamp')
-        if (first_sample_timestamp is not None and
-                first_sample_timestamp > data['timestamp']):
-            self.db.resource.update_one(
-                {'_id': data['resource_id']},
-                {'$set': {'first_sample_timestamp': data['timestamp']}}
-            )
+            # only update last sample timestamp if actually later (the usual
+            # in-order case)
+            last_sample_timestamp = resource.get('last_sample_timestamp')
+            if (last_sample_timestamp is None or
+                    last_sample_timestamp <= sample['last_sample_timestamp']):
+                self.db.resource.update_one(
+                    {'_id': sample['resource_id']},
+                    {'$set': {'metadata': sample['resource_metadata'],
+                              'last_sample_timestamp':
+                                  sample['last_sample_timestamp']}}
+                )
+
+            # only update first sample timestamp if actually earlier (
+            # the unusual out-of-order case)
+            # NOTE: a null first sample timestamp is not updated as this
+            # indicates a pre-existing resource document dating from before
+            # we started recording these timestamps in the resource collection
+            first_sample_timestamp = resource.get('first_sample_timestamp')
+            if (first_sample_timestamp is not None and
+                    first_sample_timestamp > sample['first_sample_timestamp']):
+                self.db.resource.update_one(
+                    {'_id': sample['resource_id']},
+                    {'$set': {'first_sample_timestamp':
+                              sample['first_sample_timestamp']}}
+                )
 
         # Record the raw data for the meter. Use a copy so we do not
         # modify a data structure owned by our caller (the driver adds
         # a new key '_id').
-        record = copy.copy(data)
-        record['recorded_at'] = timeutils.utcnow()
-
-        self.db.meter.insert_one(record)
+        record = copy.deepcopy(samples)
+        for s in record:
+            s['recorded_at'] = timeutils.utcnow()
+            s['resource_metadata'] = pymongo_utils.improve_keys(
+                s.pop('resource_metadata'))
+        self.db.meter.insert_many(record)
 
     def clear_expired_metering_data(self, ttl):
         """Clear expired data from the backend storage system.

ceilometer/tests/functional/storage/test_storage_scenarios.py

@@ -3198,3 +3198,39 @@ class TestRecordUnicodeSamples(DBTestBase):
         self.assertEqual(expected['counter_name'], actual['counter_name'])
         self.assertEqual(expected['resource_metadata'],
                          actual['resource_metadata'])
+
+
+@tests_db.run_with('mongodb')
+class TestBatchRecordingMetering(tests_db.TestBase):
+    def test_batch_recording_metering_data(self):
+        self.sample_dicts = []
+        for i in range(1, 10):
+            s = sample.Sample(name='sample-%s' % i,
+                              type=sample.TYPE_CUMULATIVE,
+                              unit='',
+                              volume=i * 0.1,
+                              user_id='user-id',
+                              project_id='project-id',
+                              resource_id='resource-%s' % str(i % 3),
+                              timestamp=datetime.datetime(2016, 6, 1, 15, i),
+                              resource_metadata={'fake_meta': i},
+                              source=None)
+            s_dict = utils.meter_message_from_counter(
+                s, self.CONF.publisher.telemetry_secret)
+            self.sample_dicts.append(s_dict)
+        self.conn.record_metering_data_batch(self.sample_dicts)
+        results = list(self.conn.query_samples())
+        self.assertEqual(len(self.sample_dicts), len(results))
+        for sample_item in results:
+            d = sample_item.as_dict()
+            del d['recorded_at']
+            self.assertIn(d, self.sample_dicts)
+
+        resources = list(self.conn.get_resources())
+        self.assertEqual(3, len(resources))
+        self.assertEqual('resource-0', resources[0].resource_id)
+        self.assertEqual({'fake_meta': 9}, resources[0].metadata)
+        self.assertEqual('resource-2', resources[1].resource_id)
+        self.assertEqual({'fake_meta': 8}, resources[1].metadata)
+        self.assertEqual('resource-1', resources[2].resource_id)
+        self.assertEqual({'fake_meta': 7}, resources[2].metadata)

ceilometer/tests/unit/dispatcher/test_db.py

@@ -91,7 +91,7 @@ class TestDispatcherDB(base.BaseTestCase):
 
             called = False
 
-            def record_metering_data(self, data):
+            def record_metering_data_batch(self, data):
                 self.called = True
 
         self.dispatcher._meter_conn = ErrorConnection()

releasenotes/notes/support-meter-batch-recording-mongo-6c2bdf4fbb9764eb.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - Add support of batch recording metering data to mongodb backend, since
+    the pymongo support *insert_many* interface which can be used to batch
+    record items, in "big-data" scenarios, this change can improve the
+    performance of metering data recording.