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---
stage: Systems
group: Distribution
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/product/ux/technical-writing/#assignments
---
# Avoiding required stops
Required stops are any changes to GitLab [components](architecture.md) or
dependencies that result in the need to upgrade to and stop at a specific
`major.minor` version when [upgrading GitLab](../update/index.md).
While Development maintains a [maintenance policy](../policy/maintenance.md)
that results in a three-release (3 month) backport window - GitLab maintains a
much longer window of [version support](https://about.gitlab.com/support/statement-of-support/#version-support)
that includes the current major version, as well as the two previous major
versions. Based on the schedule of previous major releases, GitLab customers can
lag behind the current release for up to three years and still expect to have
support for upgrades.
For example, a GitLab user upgrading from GitLab 14.0.12 to GitLab 16.1,
which is a fully supported [upgrade path](../update/index.md#upgrade-paths), may have
the following required stops: `14.3.6`, `14.9.5`, `14.10.5`, `15.0.5`, `15.1.6`,
`15.4.6`, and `15.11.11` before upgrading to the latest `16.1.z` version.
Past required stops have not been discovered for months after their introduction,
often as the result of extensive troubleshooting and assistance from Support
Engineers, Customer Success Managers, and Development Engineers as users upgrade
across greater than 1-3 minor releases.
Wherever possible, a required stop should be avoided. If it can't be avoided,
the required stop should be aligned to a _scheduled_ required stop.
In cases where we are considering retroactively declaring an unplanned required stop,
please contact the [Distribution team product manager](https://about.gitlab.com/handbook/product/categories/#distributionbuild-group) to advise on next steps. If there
is uncertainty about whether we should declare a required stop, the Distribution product
manager may escalate to GitLab product leadership (VP or Chief Product Officer) to make
a final determination. This may happen, for example, if a change might require a stop for
a small subset of very large self-managed installations and there are well-defined workarounds
if customers run into issues.
Scheduled required stops are often implemented for the previous `major`.`minor`
release just prior to a `major` version release in order to accommodate multiple
[planned deprecations](../update/terminology.md#deprecation) and known
[breaking changes](../update/terminology.md#breaking-change).
Additionally, as of GitLab 16, we have introduced
[_scheduled_ `major`.`minor` required stops](../update/index.md#upgrade-paths):
>>>
During GitLab 16.x, we are scheduling two or three required upgrade stops.
We will give at least two milestones of notice when we schedule a required
upgrade stop. The first planned required upgrade stop is scheduled for GitLab
16.3. If nothing is introduced requiring an upgrade stop, GitLab 16.3 will be
treated as a regular upgrade.
>>>
## Causes of required stops
### Inaccurate assumptions about completed migrations
The majority of required stops are due to assumptions about the state of the
data model in a given release, usually in the form of interdependent database
migrations, or code changes that assume that schema changes introduced in
prior migrations have completed by the time the code loads.
Designing changes and migrations for [backwards compatibility between versions](multi_version_compatibility.md) can mitigate stop concerns with continuous or
"zero-downtime" upgrades. However, the **contract** phase will likely introduce
a required stop when a migration/code change is introduced that requires
that background migrations have completed before running or loading.
WARNING:
If you're considering adding or removing a migration, or introducing code that
assumes that migrations have completed in a given release, first review
the database-related documentation on [required stops](database/required_stops.md).
#### Examples
- GitLab `12.1`: Introduced a background migration changing `merge_status` in
MergeRequests depending on the `state` value. The `state` attribute was removed
in `12.10`. It took until `13.6` to document the required stop.
- GitLab `13.8`: Includes a background migration to deal with duplicate service
records. In `13.9`, a unique index was applied in another migration that
depended on the background migration completing. Not discovered/documented until
GitLab `14.3`
- GitLab `14.3`: Includes a potentially long-running background migration against
`merge_request_diff_commits` that was foregrounded in `14.5`. This change resulted in
extensive downtime for users with large GitLab installations. Not documented
until GitLab `15.1`
- GitLab `14.9`: Includes a batched background migration for `namespaces` and `projects`
that needs to finish before another batched background migration added in `14.10` executes,
forcing a required stop. The migration can take hours or days to complete on
large GitLab installations.
Additional details as well as links to related issues and merge requests can be
found in: [Issue: Put in place measures to avoid addition/proliferation of GitLab upgrade path stops](https://gitlab.com/gitlab-org/gitlab/-/issues/375553)
### Removal of code workarounds and mitigations
Similar to assumptions about the data model/schema/migration state, required
`major.minor` stops have been introduced due to the intentional removal of
code implemented to workaround previously discovered issues.
#### Examples
- GitLab `13.1`: A security fix in Rails `6.0.3.1` introduced a CSRF token change
(causing a canary environment incident). We introduced code to maintain acceptance
of previously generated tokens, and removed the code in `13.2`, creating a known
required stop in `13.1`.
- GitLab `15.4`: Introduces a migration to fix an inaccurate `expires_at` timestamp
for job artifacts that had been mitigated in code since GitLab `14.9`. The
workaround was removed in GitLab `15.6`, causing `15.4` to be a required stop.
### Deprecations
Deprecations, particularly [breaking changes](../update/terminology.md#breaking-change)
can also cause required stops if they introduce long migration delays or require
manual actions on the part of GitLab administrators.
These are generally accepted as a required stop around a major release, either
stopping at the latest `major.minor` release immediately proceeding
a new `major` release, and potentially the lastest `major.0` patch release, and
to date, discovered required stops related to deprecations have been limited to
these releases.
#### Examples
Examples of deprecations are too numerous to be listed here, but can found
in the [deprecations and removals by version](../update/deprecations.md) as well
as the [version-specific upgrading instructions](../update/index.md#version-specific-upgrading-instructions),
[version-specific changes for the GitLab package (Omnibus)](../update/package/index.md#version-specific-changes),
and [GitLab chart upgrade notes](https://docs.gitlab.com/charts/installation/upgrade.html).
## Further reading
- [Documentation: Database - Adding required stops](database/required_stops.md)
- [Documentation: Upgrading GitLab](../update/index.md)
- [Package (Omnibus) upgrade](../update/package/index.md)
- [Docker upgrade](../install/docker.md#upgrade)
- [GitLab chart](https://docs.gitlab.com/charts/installation/upgrade.html)
- [Issue: Put in place measures to avoid addition/proliferation of GitLab upgrade path stops](https://gitlab.com/gitlab-org/gitlab/-/issues/375553)
- [Issue: Brainstorm ways for background migrations to be finalized without introducing a required upgrade step](https://gitlab.com/gitlab-org/gitlab/-/issues/357561)
- [Issue: Scheduled required paths for GitLab upgrades to improve UX](https://gitlab.com/gitlab-org/gitlab/-/issues/358417)
- [Epic: GitLab Releases and Maintenance policies](https://gitlab.com/groups/gitlab-com/gl-infra/-/epics/988)
|
