From 00065bd9f62f3a7d033d88243cffe6148b7ee540 Mon Sep 17 00:00:00 2001
From: Eugeniya Kudryashova <ekudryashova@mirantis.com>
Date: Fri, 8 Aug 2014 19:16:35 +0300
Subject: [PATCH] Decrease amount of queries while adding aggregate metadata

Dict of aggregate metadata sometimes contains a lot of items,
so while adding of metadata current implementation make a lot
of inserts in database.

Using multirow INSERT instead of INSERT statement allows to
decrease amount of queries to one single query per operation.

Change-Id: I6b842459cf198f8577b615aeba091723dcb18429
---
 nova/db/sqlalchemy/api.py    | 13 ++++++++-----
 nova/tests/db/test_db_api.py | 12 ++++++++++++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index ffc23d1c7132..3401aeead69b 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -5236,14 +5236,17 @@ def aggregate_metadata_add(context, aggregate_id, metadata, set_delete=False,
                     meta_ref.update({"value": metadata[key]})
                     already_existing_keys.add(key)
 
+                new_entries = []
                 for key, value in metadata.iteritems():
                     if key in already_existing_keys:
                         continue
-                    meta_ref = models.AggregateMetadata()
-                    meta_ref.update({"key": key,
-                                     "value": value,
-                                     "aggregate_id": aggregate_id})
-                    session.add(meta_ref)
+                    new_entries.append({"key": key,
+                                        "value": value,
+                                        "aggregate_id": aggregate_id})
+                if new_entries:
+                    session.execute(
+                        models.AggregateMetadata.__table__.insert(),
+                        new_entries)
 
             return metadata
         except db_exc.DBDuplicateEntry:
diff --git a/nova/tests/db/test_db_api.py b/nova/tests/db/test_db_api.py
index 8ad651851292..5613c162a040 100644
--- a/nova/tests/db/test_db_api.py
+++ b/nova/tests/db/test_db_api.py
@@ -578,6 +578,18 @@ class AggregateDBApiTestCase(test.TestCase):
         expected = db.aggregate_metadata_get(ctxt, result['id'])
         self.assertThat(metadata, matchers.DictMatches(expected))
 
+    def test_aggregate_metadata_add_and_update(self):
+        ctxt = context.get_admin_context()
+        result = _create_aggregate(context=ctxt)
+        metadata = _get_fake_aggr_metadata()
+        key = metadata.keys()[0]
+        new_metadata = {key: 'foo',
+                        'fake_new_key': 'fake_new_value'}
+        metadata.update(new_metadata)
+        db.aggregate_metadata_add(ctxt, result['id'], new_metadata)
+        expected = db.aggregate_metadata_get(ctxt, result['id'])
+        self.assertThat(metadata, matchers.DictMatches(expected))
+
     def test_aggregate_metadata_add_retry(self):
         ctxt = context.get_admin_context()
         result = _create_aggregate(context=ctxt, metadata=None)