gitlab-org--gitlab-foss/changelogs/unreleased/sh-eliminate-gitaly-nplus-o...

---
title: Eliminate Gitaly N+1 queries with notes API
merge_request: 32089
author:
type: performance
Eliminate Gitaly N+1 queries with notes API Similar to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31834, we see that in https://gitlab.com/gitlab-org/gitlab-ce/issues/65957 there can be hundreds, even thousands, of Gitaly requests in the `/api/:version/projects/:id/merge_requests/:noteable_id/notes` endpoint. Previously, the API to retrieve notes generated hundreds of Gitaly calls to determine whether a system note should be shown to the user. It did this by: 1. Rendering the Markdown 2. Extracting cross-references from the Markdown 3. Issuing a Gitaly `FindCommit` RPC for every reference to validate that the commit exists. The last step is unnecessary because we don't need to display a commit if the user doesn't have access to the project in the first place. `RendersNotes#prepare_notes_for_rendering` is already used in `MergeRequestsController`, which is why we don't see N+1 Gitaly calls there. We use it here to optimize the note redaction process. 2019-08-22 07:19:44 +00:00			`---`
			`title: Eliminate Gitaly N+1 queries with notes API`
			`merge_request: 32089`
			`author:`
			`type: performance`