Refresh project authorizations using a Redis lease

When I proposed using serializable transactions I was hoping we would be
able to refresh data of individual users concurrently. Unfortunately
upon closer inspection it was revealed this was not the case. This could
result in a lot of queries failing due to serialization errors,
overloading the database in the process (given enough workers trying to
update the target table).

To work around this we're now using a Redis lease that is cancelled upon
completion. This ensures we can update the data of different users
concurrently without overloading the database.

The code will try to obtain the lease until it succeeds, waiting at
least 1 second between retries. This is necessary as we may otherwise
end up _not_ updating the data which is not an option.

1 files changed, 27 insertions, 0 deletions

diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 91826e5884d..14c891994d0 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -1349,4 +1349,31 @@ describe User, models: true do
       expect(projects).to be_empty
     end
   end
+
+  describe '#refresh_authorized_projects', redis: true do
+    let(:project1) { create(:empty_project) }
+    let(:project2) { create(:empty_project) }
+    let(:user) { create(:user) }
+
+    before do
+      project1.team << [user, :reporter]
+      project2.team << [user, :guest]
+
+      user.project_authorizations.delete_all
+      user.refresh_authorized_projects
+    end
+
+    it 'refreshes the list of authorized projects' do
+      expect(user.project_authorizations.count).to eq(2)
+    end
+
+    it 'sets the authorized_projects_populated column' do
+      expect(user.authorized_projects_populated).to eq(true)
+    end
+
+    it 'stores the correct access levels' do
+      expect(user.project_authorizations.where(access_level: Gitlab::Access::GUEST).exists?).to eq(true)
+      expect(user.project_authorizations.where(access_level: Gitlab::Access::REPORTER).exists?).to eq(true)
+    end
+  end
 end