[Feature flag] Enable incremental repository backups
Summary
This issue is to rollout incremental repository backups on production,
that is currently behind the incremental_repository_backup
feature flag.
This feature configures gitaly-backup
in order to be able to take incremental repository backups.
backup.rake
is not used on .com so this feature is only to allow an easy way to revert the behaviour for on-prem installations.
Owners
- Team: Gitaly
- Most appropriate slack channel to reach out to:
#g_create_gitaly
- Best individual to reach out to: @proglottis
- PM: @mjwood
Stakeholders
Expectations
What are we expecting to happen?
Once the feature is enabled the layout for all repository backups (full or incremental) will change from the legacy layout to the pointer layout.
When is the feature viable?
N/A
What might happen if this goes wrong?
Creating or restoring a repository backup may fail.
Pointer layout is compatible with legacy layout, but legacy layout does not understand pointer layout. So backups taken with the feature enabled will not be compatible with the feature turned off.
What can we monitor to detect problems with this?
Since this feature is on-prem only. We will be relying on issues being raised.
What can we check for monitoring production after rollouts?
N/A
Rollout Steps
Release the feature with the feature flag
If you're still unsure whether the feature is deemed stable but want to release it in the current milestone, you can change the default state of the feature flag to be enabled. To do so, follow these steps:
-
Create a merge request with the following changes. Ask for review and merge it. -
Set the default_enabled
attribute in the feature flag definition totrue
. -
Create a changelog entry.
-
-
Ensure that the default-enabling MR has been deployed to both production and canary. If the merge request was deployed before the code cutoff, the feature can be officially announced in a release blog post. -
/chatops run auto_deploy status <merge-commit-of-default-enabling-mr>
-
-
Close the feature issue to indicate the feature will be released in the current milestone. -
Set the next milestone to this rollout issue for scheduling the flag removal. -
(Optional) You can create a separate issue for scheduling the steps below to Release the feature. -
Set the title to "[Feature flag] Cleanup incremental_repository_backup
". -
Execute the /copy_metadata <this-rollout-issue-link>
quick action to copy the labels from this rollout issue. -
Link this rollout issue as a related issue. -
Close this rollout issue.
-
WARNING: This approach has the downside that it makes it difficult for us to clean up the flag. For example, on-premise users could disable the feature on their GitLab instance. But when you remove the flag at some point, they suddenly see the feature as enabled and they can't roll it back to the previous behavior. To avoid this potential breaking change, use this approach only for urgent matters.
Release the feature
After the feature has been deemed stable, the clean up should be done as soon as possible to permanently enable the feature and reduce complexity in the codebase.
You can either create a follow-up issue for Feature Flag Cleanup or use the checklist below in this same issue.
-
Create a merge request to remove incremental_repository_backup
feature flag. Ask for review and merge it.-
Remove all references to the feature flag from the codebase. -
Remove the YAML definitions for the feature from the repository. -
Create a changelog entry.
-
-
Ensure that the cleanup MR has been deployed to both production and canary. If the merge request was deployed before the code cutoff, the feature can be officially announced in a release blog post. -
/chatops run auto_deploy status <merge-commit-of-cleanup-mr>
-
-
Close the feature issue to indicate the feature will be released in the current milestone. -
Clean up the feature flag from all environments by running these chatops command in #production
channel:-
/chatops run feature delete incremental_repository_backup --dev
-
/chatops run feature delete incremental_repository_backup --staging
-
/chatops run feature delete incremental_repository_backup
-
-
Close this rollout issue.
Rollback Steps
-
This feature can be disabled by running the following Chatops command:
/chatops run feature set incremental_repository_backup false