Fix an N+1 issue in GroupPackagesFinder
🌲 Context
We're going to fix the GroupPackagesFinder. This finder, as its name implies, is in charge of returning all Packages::Package
linked to a Group
through the included Project
s. It can optionally include packages from sub groups. User permissions are checked.
#267010 (closed) shed some light on issues in the #group_projects_visible_to_current_user
function.
Simply put, this function will make use of a .select
on an ActiveRecord. This has two downsides:
- Eager load all the projects in memory to make them available to the
.select
- The
.select
block will callAbility.allowed?
which will trigger a database query on project features.
Now imagine having thousands of projects returned by the .select
statement =
Note that the packages
feature is within the repository feature
of a project. As such, the visibility of the repository feature
will have a consequence if a user have access to packages or not.
What does this MR do?
The solution to the problem at hand is simply getting rid of the .select
statement.
This MR:
- Updates
#group_projects_visible_to_current_user
to replace the.select
by the corresponding.with_feature_available_for_user
scope that will properly select the projects within the SQL query- The result is that we keep an ActiveRecord relation = lazy loading is active throughout the execution of the finder.
- Updates and cleans up the associated spec:
- Add a spec example to detect the
N+1
situation - Add a tabled based spec to check permissions. Basically, matrix between project visibility, user role and repository feature visibility.
- Give some
💚 to the spec execution time by usinglet_it_be
instead oflet
orlet!
- Add a spec example to detect the
Screenshots (strongly suggested)
n / a
Does this MR meet the acceptance criteria?
Conformity
-
Changelog entry - [-] Documentation (if required)
-
Code review guidelines -
Merge request performance guidelines -
Style guides -
Database guides -
Separation of EE specific content
Availability and Testing
-
Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process. -
Tested in all supported browsers -
Informed Infrastructure department of a default or new setting change, if applicable per definition of done
Security
If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:
-
Label as security and @ mention @gitlab-com/gl-security/appsec
-
The MR includes necessary changes to maintain consistency between UI, API, email, or other methods -
Security reports checked/validated by a reviewer from the AppSec team
Database
Explain plans
From #group_projects_visible_to_current_user
SELECT "projects".*
FROM "projects"
LEFT JOIN project_features ON projects.id = project_features.project_id
WHERE "projects"."namespace_id"
IN (WITH RECURSIVE "base_and_descendants" AS (
(SELECT "namespaces".* FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND "namespaces"."id" = 6576322)
UNION
(SELECT "namespaces".* FROM "namespaces", "base_and_descendants" WHERE "namespaces"."type" = 'Group' AND "namespaces"."parent_id" = "base_and_descendants"."id")
) SELECT "namespaces"."id" FROM "base_and_descendants" AS "namespaces"
)
AND (EXISTS (SELECT 1 FROM "project_authorizations" WHERE "project_authorizations"."user_id" = 3983112 AND (project_authorizations.project_id = projects.id)) OR projects.visibility_level IN (0,10,20)) AND ("project_features"."repository_access_level" > 0 OR "project_features"."repository_access_level" IS NULL)
plan: https://explain.depesz.com/s/aflt
From #packages_for_group_projects
SELECT "packages_packages".* FROM "packages_packages" WHERE "packages_packages"."project_id" IN (SELECT "projects"."id" FROM "projects" LEFT JOIN project_features ON projects.id = project_features.project_id WHERE "projects"."namespace_id" IN (WITH RECURSIVE "base_and_descendants" AS ((SELECT "namespaces".* FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND "namespaces"."id" = 6576322)
UNION
(SELECT "namespaces".* FROM "namespaces", "base_and_descendants" WHERE "namespaces"."type" = 'Group' AND "namespaces"."parent_id" = "base_and_descendants"."id")) SELECT "namespaces"."id" FROM "base_and_descendants" AS "namespaces") AND (EXISTS (SELECT 1 FROM "project_authorizations" WHERE "project_authorizations"."user_id" = 3983112 AND (project_authorizations.project_id = projects.id)) OR projects.visibility_level IN (0,10,20)) AND ("project_features"."repository_access_level" > 0 OR "project_features"."repository_access_level" IS NULL))
AND ("packages_packages"."package_type" != 4 OR "packages_packages"."name" != 'NuGet.Temporary.Package') AND "packages_packages"."version" IS NOT NULL ORDER BY created_at ASC