BigW Consortium Gitlab

Skip to content

G
gitlab-ce
Commit ef253a1e by Stan Hu
Options

Eliminate cached N+1 queries for projects in Issue API

In CE, every `Issue` entity is also a `ProjectEntity`, which calls `entity&.project.try(:id)` to show the project ID. In an API request with 100 issues, this would hit the Rails statement cache 100 times for the same project and cause unnecessary overhead as related models would also be loaded. In EE, we call `Issue#supports_weight?` for each issue, which then calls `project&.feature_available?(:issue_weights)`. If the project is not preloaded, this incurs additional overhead, as each individual Project object has to be queried. This can lead to a significant performance hit. In loading the CE project with 100 issues, this contributed to at least 22% of the load time. See https://gitlab.com/gitlab-org/gitlab-ce/issues/47031 for why testing this is a bit tricky.
parent 37a7b590
Showing with 6 additions and 1 deletion
changelogs/unreleased/sh-fix-issue-api-perf-n-plus-one.yml 0 → 100644
---
title: Eliminate cached N+1 queries for projects in Issue API
merge_request:
author:
type: performance
lib/api/issues.rb
......@@ -16,7 +16,7 @@ module API
args[:scope] = args[:scope].underscore if args[:scope]
issues = IssuesFinder.new(current_user, args).execute
.preload(:assignees, :labels, :notes, :timelogs)
.preload(:assignees, :labels, :notes, :timelogs, :project)
issues.reorder(args[:order_by] => args[:sort])
end
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment