Merge branch 'hchouraria-docs-for-1420-pending-background-migration' into 'master'

Add doc for stuck migration in 14.2

See merge request gitlab-org/gitlab!86537

doc/update/index.md

@@ -193,6 +193,8 @@ pending_job_classes.each { |job_class| Gitlab::BackgroundMigration.steal(job_cla
 
 GitLab 13.6 introduced an issue where a background migration named `BackfillJiraTrackerDeploymentType2` can be permanently stuck in a **pending** state across upgrades. To clean up this stuck migration, see the [13.6.0 version-specific instructions](#1360).
 
+GitLab 14.2 introduced an issue where a background migration named `BackfillDraftStatusOnMergeRequests` can be permanently stuck in a **pending** state across upgrades when the instance lacks records that match the migration's target. To clean up this stuck migration, see the [14.2.0 version-specific instructions](#1420).
+
 GitLab 14.4 introduced an issue where a background migration named `PopulateTopicsTotalProjectsCountCache` can be permanently stuck in a **pending** state across upgrades when the instance lacks records that match the migration's target. To clean up this stuck migration, see the [14.4.0 version-specific instructions](#1440).
 
 GitLab 14.8 introduced an issue where a background migration named `PopulateTopicsNonPrivateProjectsCount` can be permanently stuck in a **pending** state across upgrades. To clean up this stuck migration, see the [14.8.0 version-specific instructions](#1480).
@@ -616,6 +618,17 @@ for how to proceed.
   ```
 
 - See [Maintenance mode issue in GitLab 13.9 to 14.4](#maintenance-mode-issue-in-gitlab-139-to-144).
+- GitLab 14.2.0 includes a
+  [background migration `BackfillDraftStatusOnMergeRequests`](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/67687)
+  that may remain stuck permanently in a **pending** state when the instance lacks records that match the migration's target.
+
+  To clean up this stuck job, run the following in the [GitLab Rails Console](../administration/operations/rails_console.md):
+
+  ```ruby
+  Gitlab::Database::BackgroundMigrationJob.pending.where(class_name: "BackfillDraftStatusOnMergeRequests").find_each do |job|
+    puts Gitlab::Database::BackgroundMigrationJob.mark_all_as_succeeded("BackfillDraftStatusOnMergeRequests", job.arguments)
+  end
+  ```
 
 ### 14.1.0