Sync versions: don't fetch/return all versions (#8114)

We were using this only for logging,
retrieving all versions from the db and making a string from it
may be expensive.

This may be related to the OOM error, but hard to say.
Didn't see anything else that may be causing this.

Author: stsewd

readthedocs/api/v2/utils.py

@@ -115,7 +115,10 @@ def sync_versions_to_db(project, versions, type):  # pylint: disable=redefined-b
             latest_version.verbose_name = LATEST_VERBOSE_NAME
             latest_version.save()
     if added:
-        log.info('(Sync Versions) Added Versions: [%s] ', ' '.join(added))
+        log.info(
+            '(Sync Versions) Added Versions: versions_count=%d versions=[%s]',
+            len(added), ' '.join(itertools.islice(added, 100)),
+        )
     return added
 
 
@@ -208,15 +211,12 @@ def delete_versions_from_db(project, tags_data, branches_data):
         )
         .exclude(active=True)
     )
-    deleted_versions = set(to_delete_qs.values_list('slug', flat=True))
-    if deleted_versions:
-        log.info(
-            '(Sync Versions) Deleted Versions: project=%s, versions=[%s]',
-            project.slug, ' '.join(deleted_versions),
-        )
-        to_delete_qs.delete()
-
-    return deleted_versions
+    _, deleted = to_delete_qs.delete()
+    versions_count = deleted.get('builds.Version')
+    log.info(
+        '(Sync Versions) Deleted Versions: project=%s versions_count=[%d]',
+        project.slug, versions_count,
+    )
 
 
 def get_deleted_active_versions(project, tags_data, branches_data):

readthedocs/builds/tasks.py

@@ -15,10 +15,10 @@
 )
 from readthedocs.builds.constants import (
     BRANCH,
-    EXTERNAL,
     BUILD_STATUS_FAILURE,
     BUILD_STATUS_PENDING,
     BUILD_STATUS_SUCCESS,
+    EXTERNAL,
     MAX_BUILD_COMMAND_SIZE,
     TAG,
 )
@@ -255,7 +255,7 @@ def sync_versions_task(project_pk, tags_data, branches_data, **kwargs):
 
     :param tags_data: List of dictionaries with ``verbose_name`` and ``identifier``.
     :param branches_data: Same as ``tags_data`` but for branches.
-    :returns: the identifiers for the versions that have been deleted.
+    :returns: `True` or `False` if the task succeeded.
     """
     project = Project.objects.get(pk=project_pk)
 
@@ -284,7 +284,7 @@ def sync_versions_task(project_pk, tags_data, branches_data, **kwargs):
         )
         added_versions.update(result)
 
-        deleted_versions = delete_versions_from_db(
+        delete_versions_from_db(
             project=project,
             tags_data=tags_data,
             branches_data=branches_data,
@@ -296,7 +296,7 @@ def sync_versions_task(project_pk, tags_data, branches_data, **kwargs):
         )
     except Exception:
         log.exception('Sync Versions Error')
-        return [], []
+        return False
 
     try:
         # The order of added_versions isn't deterministic.
@@ -333,5 +333,4 @@ def sync_versions_task(project_pk, tags_data, branches_data, **kwargs):
             promoted_version.active = True
             promoted_version.save()
             trigger_build(project=project, version=promoted_version)
-
-    return list(added_versions), list(deleted_versions)
+    return True

readthedocs/rtd_tests/tests/test_sync_versions.py

@@ -56,6 +56,7 @@ def setUp(self):
             type=TAG,
         )
         self.pip.update_stable_version()
+        self.pip.save()
 
     def test_proper_url_no_slash(self):
         branches_data = [
@@ -69,13 +70,19 @@ def test_proper_url_no_slash(self):
             },
         ]
 
-        added_versions, deleted_versions = sync_versions_task(
+        self.assertEqual(
+            set(self.pip.versions.all().values_list('slug', flat=True)),
+            {'master', 'latest', 'stable', '0.8.1', '0.8', 'to_delete'},
+        )
+        sync_versions_task(
             self.pip.pk,
             branches_data=branches_data,
             tags_data=[],
         )
-        self.assertEqual(deleted_versions, ['to_delete'])
-        self.assertEqual(added_versions, ['to_add'])
+        self.assertEqual(
+            set(self.pip.versions.all().values_list('slug', flat=True)),
+            {'master', 'latest', 'stable', '0.8.1', '0.8', 'to_add'},
+        )
 
     def test_new_tag_update_active(self):
         Version.objects.create(