diff --git a/.gitlab/ci/rules.gitlab-ci.yml b/.gitlab/ci/rules.gitlab-ci.yml
index 008b62f6a0f..bf097ae660c 100644
--- a/.gitlab/ci/rules.gitlab-ci.yml
+++ b/.gitlab/ci/rules.gitlab-ci.yml
@@ -600,9 +600,13 @@
     - <<: *if-stable-branch-refs
       when: never
     - <<: *if-merge-request-labels-as-if-jh
+      allow_failure: true
     - <<: *if-merge-request-labels-run-all-rspec
+      allow_failure: true
     - changes: *code-backstage-qa-patterns
+      allow_failure: true
     - changes: *startup-css-patterns
+      allow_failure: true
 
 .frontend:rules:default-frontend-jobs:
   rules:
@@ -637,11 +641,15 @@
     - <<: *if-stable-branch-refs
       when: never
     - <<: *if-merge-request-labels-as-if-jh
+      allow_failure: true
     - <<: *if-merge-request-labels-run-all-rspec
+      allow_failure: true
     - <<: *if-merge-request
       changes: *startup-css-patterns
+      allow_failure: true
     - <<: *if-merge-request
       changes: *ci-patterns
+      allow_failure: true
 
 .frontend:rules:jest:
   rules:
@@ -1798,9 +1806,13 @@
     - <<: *if-stable-branch-refs
       when: never
     - <<: *if-merge-request-labels-as-if-jh
+      allow_failure: true
     - <<: *if-merge-request-labels-run-all-rspec
+      allow_failure: true
     - changes: *code-backstage-qa-patterns
+      allow_failure: true
     - changes: *startup-css-patterns
+      allow_failure: true
 
 #######################
 # Test metadata rules #
diff --git a/.markdownlint.yml b/.markdownlint.yml
index 77da3b22fbd..e1e2b246314 100644
--- a/.markdownlint.yml
+++ b/.markdownlint.yml
@@ -92,7 +92,7 @@ proper-names:
     "markdownlint",
     "Mattermost",
     "Microsoft",
-    "Minikube",
+    "minikube",
     "MinIO",
     "ModSecurity",
     "NGINX Ingress",
diff --git a/app/assets/javascripts/diffs/components/compare_versions.vue b/app/assets/javascripts/diffs/components/compare_versions.vue
index da918947cc5..442807587d5 100644
--- a/app/assets/javascripts/diffs/components/compare_versions.vue
+++ b/app/assets/javascripts/diffs/components/compare_versions.vue
@@ -182,7 +182,7 @@ export default {
           class="gl-mr-3"
           @click="expandAllFiles"
         >
-          {{ __('Expand all') }}
+          {{ __('Expand all files') }}
         </gl-button>
         <settings-dropdown />
       </div>
diff --git a/doc/.vale/gitlab/spelling-exceptions.txt b/doc/.vale/gitlab/spelling-exceptions.txt
index 307aaf8f8b8..98254c2259b 100644
--- a/doc/.vale/gitlab/spelling-exceptions.txt
+++ b/doc/.vale/gitlab/spelling-exceptions.txt
@@ -366,7 +366,7 @@ Microsoft
 middleware
 middlewares
 migratus
-Minikube
+minikube
 MinIO
 misconfiguration
 misconfigurations
diff --git a/doc/administration/compliance.md b/doc/administration/compliance.md
index 0bdaeaed971..843d5d0930a 100644
--- a/doc/administration/compliance.md
+++ b/doc/administration/compliance.md
@@ -6,37 +6,49 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # Compliance features **(FREE)**
 
-These GitLab features can help ensure that your GitLab instance meets common compliance standards. For more information
-about compliance management, see the compliance management [solutions page](https://about.gitlab.com/solutions/compliance/).
+These GitLab features can help ensure that your GitLab instance meets common
+compliance standards. For more information about compliance management, see the
+compliance management [solutions page](https://about.gitlab.com/solutions/compliance/).
 
-The [security features](../security/index.md) in GitLab may also help you meet relevant compliance standards.
+The [security features](../security/index.md) in GitLab may also help you meet
+relevant compliance standards.
 
 ## Policy management
 
-Organizations have unique policy requirements, either due to organizational standards or mandates from regulatory bodies.
-The following features help you define rules and policies to adhere to workflow requirements, separation of duties, and
-secure supply chain best practices:
+Organizations have unique policy requirements, either due to organizational
+standards or mandates from regulatory bodies. The following features help you 
+define rules and policies to adhere to workflow requirements, separation of duties,
+and secure supply chain best practices:
 
-- [**Credentials inventory**](../user/admin_area/credentials_inventory.md) (for instances): With a credentials inventory,
-  GitLab administrators can keep track of the credentials used by all of the users in their GitLab instance.
-- [**Granular user roles and flexible permissions**](../user/permissions.md) (for instances, groups, and projects): Manage
-  access and permissions with five different user roles and settings for external users. Set permissions according to people's
-  role, rather than either read or write access to a repository. Don't share the source code with people that only need
-  access to the issue tracker.
-- [**Merge request approvals**](../user/project/merge_requests/approvals/index.md) (for instances, groups, and projects):
-  Configure approvals required for merge requests.
-- [**Push rules**](../push_rules/push_rules.md) (for instances, groups, and projects): Control pushes to your
-  repositories.
+- [**Credentials inventory**](../user/admin_area/credentials_inventory.md) (for
+  instances): With a credentials inventory, GitLab administrators can keep track
+  of the credentials used by all of the users in their GitLab instance.
+- [**Granular user roles and flexible permissions**](../user/permissions.md)
+  (for instances, groups, and projects): Manage access and permissions with five
+  different user roles and settings for external users. Set permissions according
+  to people's role, rather than either read or write access to a repository. Don't
+  share the source code with people that only need access to the issue tracker.
+- [**Merge request approvals**](../user/project/merge_requests/approvals/index.md)
+  (for instances, groups, and projects): Configure approvals required for
+  merge requests.
+- [**Push rules**](../push_rules/push_rules.md) (for instances, groups, and
+  projects): Control pushes to your repositories.
 - Separation of duties using [**protected branches**](../user/project/protected_branches.md#require-code-owner-approval-on-a-protected-branch)
-  and [**custom CI/CD configuration paths**](../ci/pipelines/settings.md#specify-a-custom-cicd-configuration-file) (for projects):
-  Users can leverage the GitLab cross-project YAML configurations to define deployers of code and developers of code.
-  See how to use this setup to define these roles in:
+  and [**custom CI/CD configuration paths**](../ci/pipelines/settings.md#specify-a-custom-cicd-configuration-file) (for projects): Users can leverage the GitLab cross-project YAML configurations
+  to define deployers of code and developers of code. See how to use this setup
+  to define these roles in:
   - The [Separation of Duties deploy project](https://gitlab.com/guided-explorations/separation-of-duties-deploy/blob/master/README.md).
   - The [Separation of Duties project](https://gitlab.com/guided-explorations/separation-of-duties/blob/master/README.md).
 
 ## Compliant workflow automation
 
-It is important for compliance teams to be confident that their controls and requirements are set up correctly, but also that they _stay_ set up correctly. One way of doing this is manually checking settings periodically, but this is error prone and time consuming. A better approach is to use single-source-of-truth settings and automation to ensure that whatever a compliance team has configured, stays configured and working correctly. These features can help you automate compliance:
+It is important for compliance teams to be confident that their controls and
+requirements are set up correctly, but also that they _stay_ set up correctly.
+One way of doing this is manually checking settings periodically, but this is
+error prone and time consuming. A better approach is to use single-source-of-truth
+settings and automation to ensure that whatever a compliance team has configured,
+stays configured and working correctly. These features can help you automate
+compliance:
 
 - [**Compliance frameworks**](../user/project/settings/index.md#compliance-frameworks) (for groups): Create a custom
   compliance framework at the group level to describe the type of compliance requirements any child project needs to follow.
@@ -45,46 +57,59 @@ It is important for compliance teams to be confident that their controls and req
 
 ## Audit management
 
-An important part of any compliance program is being able to go back and understand what happened, when
-it happened, and who was responsible. This is useful in audit situations as well as for understanding
-the root cause of issues when they occur. It is useful to have both low-level, raw lists of audit data
-as well as high-level, summary lists of audit data. Between these two, compliance teams can quickly
-identify if problems exist and then drill down into the specifics of those issues. These features can help provide visibility into GitLab and audit what is happening:
+An important part of any compliance program is being able to go back and understand
+what happened, when it happened, and who was responsible. This is useful in audit
+situations as well as for understanding the root cause of issues when they occur.
+It is useful to have both low-level, raw lists of audit data as well as high-level,
+summary lists of audit data. Between these two, compliance teams can quickly
+identify if problems exist and then drill down into the specifics of those issues.
+These features can help provide visibility into GitLab and audit what is happening:
 
-- [**Audit events**](audit_events.md) (for instances, groups, and projects): To maintain the integrity of your code,
-  audit events give administrators the ability to view any modifications made within the GitLab
-  server in an advanced audit events system, so you can control, analyze, and track every change.
-- [**Audit reports**](audit_reports.md) (for instances, groups, and projects): Create and access reports based on the
-  audit events that have occurred. Use pre-built GitLab reports or the API to build your own.
-- [**Auditor users**](auditor_users.md) (for instances): Auditor users are users who are given read-only access to all
-  projects, groups, and other resources on the GitLab instance.
-- [**Compliance report**](../user/compliance/compliance_report/index.md) (for groups): Quickly get visibility into the
-  compliance posture of your organization.
+- [**Audit events**](audit_events.md) (for instances, groups, and projects): To
+  maintain the integrity of your code, audit events give administrators the
+  ability to view any modifications made within the GitLab server in an advanced
+  audit events system, so you can control, analyze, and track every change.
+- [**Audit reports**](audit_reports.md) (for instances, groups, and projects):
+  Create and access reports based on the audit events that have occurred. Use
+  pre-built GitLab reports or the API to build your own.
+- [**Auditor users**](auditor_users.md) (for instances): Auditor users are users
+  who are given read-only access to all projects, groups, and other resources on
+  the GitLab instance.
+- [**Compliance report**](../user/compliance/compliance_report/index.md) (for
+  groups): Quickly get visibility into the compliance posture of your organization.
 
 ## Other compliance features
 
 These features can also help with compliance requirements:
 
-- [**Email all users of a project, group, or entire server**](../tools/email.md) (for instances): An administrator can
-  email groups of users based on project or group membership, or email everyone using the GitLab instance. These emails
+- [**Email all users of a project, group, or entire server**](../tools/email.md)
+  (for instances): An administrator can email groups of users based on project
+  or group membership, or email everyone using the GitLab instance. These emails
   are great for scheduled maintenance or upgrades.
-- [**Enforce ToS acceptance**](../user/admin_area/settings/terms.md) (for instances): Enforce your users accepting new
-  terms of service by blocking GitLab traffic.
-- [**External Status Checks**](../user/project/merge_requests/status_checks.md) (for projects): Interface with third-party
-  systems you already use during development to ensure you remain compliant.
-- [**Generate reports on permission levels of users**](../user/admin_area/index.md#user-permission-export) (for
-  instances): Administrators can generate a report listing all users' access permissions for groups and projects in the
-  instance.
-- [**License compliance**](../user/compliance/license_compliance/index.md) (for projects): Search dependencies for their
-  licenses. This lets you determine if the licenses of your project's dependencies are compatible with your project's license.
-- [**Lock project membership to group**](../user/group/index.md#prevent-members-from-being-added-to-projects-in-a-group) (for
-  groups): Group owners can prevent new members from being added to projects within a group.
-- [**LDAP group sync**](auth/ldap/ldap_synchronization.md#group-sync) (for instances): Gives administrators the ability
-  to automatically sync groups and manage SSH keys, permissions, and authentication, so you can focus on building your
-  product, not configuring your tools.
-- [**LDAP group sync filters**](auth/ldap/ldap_synchronization.md#group-sync) (for instances): Gives more flexibility to
-  synchronize with LDAP based on filters, meaning you can leverage LDAP attributes to map GitLab permissions.
+- [**Enforce ToS acceptance**](../user/admin_area/settings/terms.md) (for
+  instances): Enforce your users accepting new terms of service by blocking GitLab
+  traffic.
+- [**External Status Checks**](../user/project/merge_requests/status_checks.md)
+  (for projects): Interface with third-party systems you already use during
+  development to ensure you remain compliant.
+- [**Generate reports on permission levels of users**](../user/admin_area/index.md#user-permission-export)
+  (for instances): Administrators can generate a report listing all users' access
+  permissions for groups and projects in the instance.
+- [**License compliance**](../user/compliance/license_compliance/index.md) (for
+  projects): Search dependencies for their licenses. This lets you determine if
+  the licenses of your project's dependencies are compatible with your project's
+  license.
+- [**Lock project membership to group**](../user/group/index.md#prevent-members-from-being-added-to-projects-in-a-group)
+  (for groups): Group owners can prevent new members from being added to projects
+  within a group.
+- [**LDAP group sync**](auth/ldap/ldap_synchronization.md#group-sync) (for
+  instances): Gives administrators the ability to automatically sync groups and
+  manage SSH keys, permissions, and authentication, so you can focus on building
+  your product, not configuring your tools.
+- [**LDAP group sync filters**](auth/ldap/ldap_synchronization.md#group-sync)
+  (for instances): Gives more flexibility to synchronize with LDAP based on
+  filters, meaning you can leverage LDAP attributes to map GitLab permissions.
 - [**Omnibus GitLab package supports log forwarding**](https://docs.gitlab.com/omnibus/settings/logs.html#udp-log-forwarding)
   (for instances): Forward your logs to a central system.
-- [**Restrict SSH Keys**](../security/ssh_keys_restrictions.md) (for instances): Control the technology and key length
-  of SSH keys used to access GitLab.
+- [**Restrict SSH Keys**](../security/ssh_keys_restrictions.md) (for instances):
+  Control the technology and key length of SSH keys used to access GitLab.
diff --git a/doc/administration/geo/replication/datatypes.md b/doc/administration/geo/replication/datatypes.md
index dbd8962414b..0fa08dcc9e0 100644
--- a/doc/administration/geo/replication/datatypes.md
+++ b/doc/administration/geo/replication/datatypes.md
@@ -188,7 +188,7 @@ successfully, you must replicate their data using some other means.
 |[Project repository](../../../user/project/repository/)                                                        | **Yes** (10.2)                                                          | **Yes** (10.7)                                                             | No                                                                            |       |
 |[Project wiki repository](../../../user/project/wiki/)                                                         | **Yes** (10.2)                                                          | **Yes** (10.7)                                                             | No                                                                            |       |
 |[Group wiki repository](../../../user/project/wiki/group.md)                                                   | [**Yes** (13.10)](https://gitlab.com/gitlab-org/gitlab/-/issues/208147) | No                                                                         | No                                                                            | Behind feature flag `geo_group_wiki_repository_replication`, enabled by default. |
-|[Uploads](../../uploads.md)                                                                                    | **Yes** (10.2)                                                          | **Yes** (14.6)                                                             | Via Object Storage provider if supported. Native Geo support (Beta).          | Replication is behind the feature flag `geo_upload_replication`, enabled by default. Verification is behind the feature flag `geo_upload_verification` introduced and enabled by default in 14.6. |
+|[Uploads](../../uploads.md)                                                                                    | **Yes** (10.2)                                                          | **Yes** (14.6)                                                             | Via Object Storage provider if supported. Native Geo support (Beta).          | Replication is behind the feature flag `geo_upload_replication`, enabled by default. Verification was behind the feature flag `geo_upload_verification`, removed in 14.8. |
 |[LFS objects](../../lfs/index.md)                                                                              | **Yes** (10.2)                                                          | **Yes** (14.6)                                                             | Via Object Storage provider if supported. Native Geo support (Beta).          | GitLab versions 11.11.x and 12.0.x are affected by [a bug that prevents any new LFS objects from replicating](https://gitlab.com/gitlab-org/gitlab/-/issues/32696).<br /><br />Replication is behind the feature flag `geo_lfs_object_replication`, enabled by default. Verification was behind the feature flag `geo_lfs_object_verification`, removed in 14.7. |
 |[Personal snippets](../../../user/snippets.md)                                                                 | **Yes** (10.2)                                                          | **Yes** (10.2)                                                             | No                                                                            |       |
 |[Project snippets](../../../user/snippets.md)                                                                  | **Yes** (10.2)                                                          | **Yes** (10.2)                                                             | No                                                                            |       |
diff --git a/doc/administration/gitaly/index.md b/doc/administration/gitaly/index.md
index b48f015a9ca..4d60832720b 100644
--- a/doc/administration/gitaly/index.md
+++ b/doc/administration/gitaly/index.md
@@ -533,12 +533,14 @@ You can also monitor the [Praefect logs](../logs.md#praefect-logs).
 
 #### Database metrics `/db_metrics` endpoint
 
+> [Introduced](https://gitlab.com/gitlab-org/gitaly/-/issues/3286) in GitLab 14.5.
+
 The following metrics are available from the `/db_metrics` endpoint:
 
 - `gitaly_praefect_unavailable_repositories`, the number of repositories that have no healthy, up to date replicas.
 - `gitaly_praefect_read_only_repositories`, the number of repositories in read-only mode within a virtual storage.
-  This is an older metric that is still available for backwards compatibility reasons. `gitaly_praefect_unavailable_repositories`
-  is a more accurate.
+  This metric is available for backwards compatibility reasons. `gitaly_praefect_unavailable_repositories` is more
+  accurate.
 - `gitaly_praefect_replication_queue_depth`, the number of jobs in the replication queue.
 
 ## Recover from failure
diff --git a/doc/administration/troubleshooting/kubernetes_cheat_sheet.md b/doc/administration/troubleshooting/kubernetes_cheat_sheet.md
index 8c756260f05..290d6d9f21d 100644
--- a/doc/administration/troubleshooting/kubernetes_cheat_sheet.md
+++ b/doc/administration/troubleshooting/kubernetes_cheat_sheet.md
@@ -221,9 +221,9 @@ all Kubernetes resources and dependent charts:
   helm get manifest <release name>
   ```
 
-## Installation of minimal GitLab configuration via Minikube on macOS
+## Installation of minimal GitLab configuration via minikube on macOS
 
-This section is based on [Developing for Kubernetes with Minikube](https://docs.gitlab.com/charts/development/minikube/index.html)
+This section is based on [Developing for Kubernetes with minikube](https://docs.gitlab.com/charts/development/minikube/index.html)
 and [Helm](https://docs.gitlab.com/charts/installation/tools.html#helm). Refer
 to those documents for details.
 
@@ -233,13 +233,13 @@ to those documents for details.
   brew install kubernetes-cli
   ```
 
-- Install Minikube via Homebrew:
+- Install minikube via Homebrew:
 
   ```shell
   brew cask install minikube
   ```
 
-- Start Minikube and configure it. If Minikube cannot start, try running `minikube delete && minikube start`
+- Start minikube and configure it. If minikube cannot start, try running `minikube delete && minikube start`
   and repeat the steps:
 
   ```shell
@@ -253,7 +253,7 @@ to those documents for details.
   brew install helm
   ```
 
-- Copy the [Minikube minimum values YAML file](https://gitlab.com/gitlab-org/charts/gitlab/raw/master/examples/values-minikube-minimum.yaml)
+- Copy the [minikube minimum values YAML file](https://gitlab.com/gitlab-org/charts/gitlab/raw/master/examples/values-minikube-minimum.yaml)
   to your workstation:
 
   ```shell
diff --git a/doc/development/architecture.md b/doc/development/architecture.md
index 078eb5dd0de..36d3655ba93 100644
--- a/doc/development/architecture.md
+++ b/doc/development/architecture.md
@@ -339,7 +339,7 @@ Component statuses are linked to configuration documentation for each component.
 
 ### Component list
 
-| Component                                             | Description                                                          | [Omnibus GitLab](https://docs.gitlab.com/omnibus/) | [GitLab Environment Toolkit (GET)](https://gitlab.com/gitlab-org/quality/gitlab-environment-toolkit) | [GitLab chart](https://docs.gitlab.com/charts/) | [Minikube Minimal](https://docs.gitlab.com/charts/development/minikube/#deploying-gitlab-with-minimal-settings) | [GitLab.com](https://gitlab.com) | [Source](../install/installation.md) | [GDK](https://gitlab.com/gitlab-org/gitlab-development-kit) |  [CE/EE](https://about.gitlab.com/install/ce-or-ee/)  |
+| Component                                             | Description                                                          | [Omnibus GitLab](https://docs.gitlab.com/omnibus/) | [GitLab Environment Toolkit (GET)](https://gitlab.com/gitlab-org/quality/gitlab-environment-toolkit) | [GitLab chart](https://docs.gitlab.com/charts/) | [minikube Minimal](https://docs.gitlab.com/charts/development/minikube/#deploying-gitlab-with-minimal-settings) | [GitLab.com](https://gitlab.com) | [Source](../install/installation.md) | [GDK](https://gitlab.com/gitlab-org/gitlab-development-kit) |  [CE/EE](https://about.gitlab.com/install/ce-or-ee/)  |
 |-------------------------------------------------------|----------------------------------------------------------------------|:--------------:|:--------------:|:------------:|:----------------:|:----------:|:------:|:---:|:-------:|
 | [Certificate Management](#certificate-management)     | TLS Settings, Let's Encrypt                                          |       ✅       |       ✅        |      ✅       |        ⚙         |     ✅      |   ⚙    |  ⚙  | CE & EE |
 | [Consul](#consul)                                     | Database node discovery, failover                                    |       ⚙       |       ✅         |      ❌       |        ❌         |     ✅      |   ❌    |  ❌  | EE Only |
@@ -797,7 +797,7 @@ For monitoring deployed apps, see the [Sentry integration docs](../operations/er
 - Configuration:
   - [Omnibus](https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/files/gitlab-config-template/gitlab.rb.template)
   - [Charts](https://docs.gitlab.com/charts/charts/gitlab/sidekiq/)
-  - [Minikube Minimal](https://docs.gitlab.com/charts/charts/gitlab/sidekiq/index.html)
+  - [minikube Minimal](https://docs.gitlab.com/charts/charts/gitlab/sidekiq/index.html)
   - [Source](https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/gitlab.yml.example)
   - [GDK](https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/gitlab.yml.example)
 - Layer: Core Service (Processor)
diff --git a/doc/development/documentation/styleguide/word_list.md b/doc/development/documentation/styleguide/word_list.md
index a8c5bf6b579..dc3dcba0c95 100644
--- a/doc/development/documentation/styleguide/word_list.md
+++ b/doc/development/documentation/styleguide/word_list.md
@@ -25,6 +25,13 @@ Try to avoid **`@mention`**. Say **mention** instead, and consider linking to th
 [mentions topic](../../../user/discussions/index.md#mentions).
 Don't use backticks.
 
+## 2FA, two-factor authentication
+
+Spell out **two-factor authentication** in sentence case for the first use and in section headings, and **2FA**
+thereafter. If the first word in a sentence, do not capitalize `factor` or `authentication`. For example:
+
+- Two-factor authentication (2FA) helps secure your account. Set up 2FA when you first log in.
+
 ## above
 
 Try to avoid using **above** when referring to an example or table in a documentation page. If required, use **previous** instead. For example:
@@ -846,6 +853,10 @@ You **turn on** or **turn off** a toggle. For example:
 
 - Turn on the **blah** toggle.
 
+## TFA, two-factor authentication
+
+Use [**2FA** and **two-factor authentication**](#2fa-two-factor-authentication) instead.
+
 ## type
 
 Do not use **type** if you can avoid it. Use **enter** instead.
diff --git a/doc/security/rate_limits.md b/doc/security/rate_limits.md
index 73cc222f843..14fc526ca7e 100644
--- a/doc/security/rate_limits.md
+++ b/doc/security/rate_limits.md
@@ -87,6 +87,33 @@ There is a rate limit for [testing webhooks](../user/project/integrations/webhoo
 
 The **rate limit** is 5 requests per minute per user.
 
+### Users sign up
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77835) in GitLab 14.7.
+
+There is a rate limit per IP address on the `/users/sign_up` endpoint. This is to mitigate attempts to misuse the endpoint. For example, to mass
+discover usernames or email addresses in use. 
+
+The **rate limit** is 20 calls per minute per IP address.
+
+### Update username
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77221) in GitLab 14.7.
+
+There is a rate limit on the update username action. This is enforced to mitigate misuse of the feature. For example, to mass discover
+which usernames are in use.
+
+The **rate limit** is 10 calls per minute per signed-in user.
+
+### Username exists
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77119) in GitLab 14.7.
+
+There is a rate limit for the internal endpoint `/users/:username/exists`, used by registration to perform a client-side validation for
+uniqueness of the chosen username. This is to mitigate the risk of misuses, such as mass discovery of usernames in use.
+
+The **rate limit** is 20 calls per minute per IP address. 
+
 ## Troubleshooting
 
 ### Rack Attack is denylisting the load balancer
diff --git a/doc/user/clusters/applications.md b/doc/user/clusters/applications.md
index 9c1908f3d25..f880e603133 100644
--- a/doc/user/clusters/applications.md
+++ b/doc/user/clusters/applications.md
@@ -443,7 +443,7 @@ You can check the recommended variables for each cluster type in the official do
 - [Google GKE](https://docs.cilium.io/en/v1.8/gettingstarted/k8s-install-gke/#deploy-cilium)
 - [AWS EKS](https://docs.cilium.io/en/v1.8/gettingstarted/k8s-install-eks/#deploy-cilium)
 
-Do not use `clusterType` for sandbox environments like [Minikube](https://minikube.sigs.k8s.io/docs/).
+Do not use `clusterType` for sandbox environments like [minikube](https://minikube.sigs.k8s.io/docs/).
 
 You can customize Cilium's Helm variables by defining the
 `.gitlab/managed-apps/cilium/values.yaml` file in your cluster
diff --git a/doc/user/infrastructure/clusters/manage/management_project_applications/cilium.md b/doc/user/infrastructure/clusters/manage/management_project_applications/cilium.md
index b5959624954..5d704a2c6df 100644
--- a/doc/user/infrastructure/clusters/manage/management_project_applications/cilium.md
+++ b/doc/user/infrastructure/clusters/manage/management_project_applications/cilium.md
@@ -37,7 +37,7 @@ You can check the recommended variables for each cluster type in the official do
 - [Google GKE](https://docs.cilium.io/en/v1.8/gettingstarted/k8s-install-gke/#deploy-cilium)
 - [AWS EKS](https://docs.cilium.io/en/v1.8/gettingstarted/k8s-install-eks/#deploy-cilium)
 
-Do not use `clusterType` for sandbox environments like [Minikube](https://minikube.sigs.k8s.io/docs/).
+Do not use `clusterType` for sandbox environments like [minikube](https://minikube.sigs.k8s.io/docs/).
 
 You can customize Cilium's Helm variables by defining the
 `applications/cilium/values.yaml` file in your cluster
diff --git a/lib/gitlab/background_migration/base_job.rb b/lib/gitlab/background_migration/base_job.rb
new file mode 100644
index 00000000000..e21e7e0e4a3
--- /dev/null
+++ b/lib/gitlab/background_migration/base_job.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # Simple base class for background migration job classes which are executed through the sidekiq queue.
+    #
+    # Any job class that inherits from the base class will have connection to the tracking database set on
+    # initialization.
+    class BaseJob
+      def initialize(connection:)
+        @connection = connection
+      end
+
+      def perform(*arguments)
+        raise NotImplementedError, "subclasses of #{self.class.name} must implement #{__method__}"
+      end
+
+      private
+
+      attr_reader :connection
+    end
+  end
+end
diff --git a/lib/gitlab/background_migration/job_coordinator.rb b/lib/gitlab/background_migration/job_coordinator.rb
index 08802ad7f7f..5dc77f935e3 100644
--- a/lib/gitlab/background_migration/job_coordinator.rb
+++ b/lib/gitlab/background_migration/job_coordinator.rb
@@ -81,7 +81,7 @@ module Gitlab
 
       def perform(class_name, arguments)
         with_shared_connection do
-          migration_class_for(class_name).new.perform(*arguments)
+          migration_instance_for(class_name).perform(*arguments)
         end
       end
 
@@ -115,6 +115,16 @@ module Gitlab
         enqueued_job?([retry_set], migration_class)
       end
 
+      def migration_instance_for(class_name)
+        migration_class = migration_class_for(class_name)
+
+        if migration_class < Gitlab::BackgroundMigration::BaseJob
+          migration_class.new(connection: connection)
+        else
+          migration_class.new
+        end
+      end
+
       def migration_class_for(class_name)
         Gitlab::BackgroundMigration.const_get(class_name, false)
       end
diff --git a/lib/gitlab/database/background_migration_job.rb b/lib/gitlab/database/background_migration_job.rb
index c046571a111..c0e3016fd3d 100644
--- a/lib/gitlab/database/background_migration_job.rb
+++ b/lib/gitlab/database/background_migration_job.rb
@@ -2,7 +2,7 @@
 
 module Gitlab
   module Database
-    class BackgroundMigrationJob < ActiveRecord::Base # rubocop:disable Rails/ApplicationRecord
+    class BackgroundMigrationJob < SharedModel
       include EachBatch
       include BulkInsertSafe
 
diff --git a/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table.rb b/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table.rb
index 17a42d997e6..f551fa06cad 100644
--- a/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table.rb
+++ b/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table.rb
@@ -4,7 +4,7 @@ module Gitlab
   module Database
     module PartitioningMigrationHelpers
       # Class that will generically copy data from a given table into its corresponding partitioned table
-      class BackfillPartitionedTable
+      class BackfillPartitionedTable < ::Gitlab::BackgroundMigration::BaseJob
         include ::Gitlab::Database::DynamicModelHelpers
 
         SUB_BATCH_SIZE = 2_500
@@ -21,7 +21,7 @@ module Gitlab
             return
           end
 
-          bulk_copy = BulkCopy.new(source_table, partitioned_table, source_column)
+          bulk_copy = BulkCopy.new(source_table, partitioned_table, source_column, connection: connection)
           parent_batch_relation = relation_scoped_to_range(source_table, source_column, start_id, stop_id)
 
           parent_batch_relation.each_batch(of: SUB_BATCH_SIZE) do |sub_batch|
@@ -36,10 +36,6 @@ module Gitlab
 
         private
 
-        def connection
-          ActiveRecord::Base.connection
-        end
-
         def transaction_open?
           connection.transaction_open?
         end
@@ -53,7 +49,8 @@ module Gitlab
         end
 
         def relation_scoped_to_range(source_table, source_key_column, start_id, stop_id)
-          define_batchable_model(source_table).where(source_key_column => start_id..stop_id)
+          define_batchable_model(source_table)
+            .where(source_key_column => start_id..stop_id)
         end
 
         def mark_jobs_as_succeeded(*arguments)
@@ -64,12 +61,13 @@ module Gitlab
         class BulkCopy
           DELIMITER = ', '
 
-          attr_reader :source_table, :destination_table, :source_column
+          attr_reader :source_table, :destination_table, :source_column, :connection
 
-          def initialize(source_table, destination_table, source_column)
+          def initialize(source_table, destination_table, source_column, connection:)
             @source_table = source_table
             @destination_table = destination_table
             @source_column = source_column
+            @connection = connection
           end
 
           def copy_between(start_id, stop_id)
@@ -85,10 +83,6 @@ module Gitlab
 
           private
 
-          def connection
-            @connection ||= ActiveRecord::Base.connection
-          end
-
           def column_listing
             @column_listing ||= connection.columns(source_table).map(&:name).join(DELIMITER)
           end
diff --git a/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb b/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb
index c382d2f0715..984c708aa48 100644
--- a/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb
+++ b/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb
@@ -406,7 +406,8 @@ module Gitlab
         end
 
         def copy_missed_records(source_table_name, partitioned_table_name, source_column)
-          backfill_table = BackfillPartitionedTable.new
+          backfill_table = BackfillPartitionedTable.new(connection: connection)
+
           relation = ::Gitlab::Database::BackgroundMigrationJob.pending
             .for_partitioning_migration(MIGRATION_CLASS_NAME, source_table_name)
 
diff --git a/spec/lib/gitlab/background_migration/base_job_spec.rb b/spec/lib/gitlab/background_migration/base_job_spec.rb
new file mode 100644
index 00000000000..86abe4257e4
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/base_job_spec.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::BaseJob, '#perform' do
+  let(:connection) { double(:connection) }
+
+  let(:test_job_class) { Class.new(described_class) }
+  let(:test_job) { test_job_class.new(connection: connection) }
+
+  describe '#perform' do
+    it 'raises an error if not overridden by a subclass' do
+      expect { test_job.perform }.to raise_error(NotImplementedError, /must implement perform/)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/background_migration/job_coordinator_spec.rb b/spec/lib/gitlab/background_migration/job_coordinator_spec.rb
index 7a524d1489a..43d41408e66 100644
--- a/spec/lib/gitlab/background_migration/job_coordinator_spec.rb
+++ b/spec/lib/gitlab/background_migration/job_coordinator_spec.rb
@@ -202,23 +202,50 @@ RSpec.describe Gitlab::BackgroundMigration::JobCoordinator do
   end
 
   describe '#perform' do
-    let(:migration) { spy(:migration) }
-    let(:connection) { double('connection') }
+    let(:connection) { double(:connection) }
 
     before do
-      stub_const('Gitlab::BackgroundMigration::Foo', migration)
-
       allow(coordinator).to receive(:connection).and_return(connection)
     end
 
-    it 'performs a background migration with the configured shared connection' do
-      expect(coordinator).to receive(:with_shared_connection).and_call_original
+    context 'when the background migration does not inherit from BaseJob' do
+      let(:migration_class) { Class.new }
 
-      expect(migration).to receive(:perform).with(10, 20).once do
-        expect(Gitlab::Database::SharedModel.connection).to be(connection)
+      before do
+        stub_const('Gitlab::BackgroundMigration::Foo', migration_class)
       end
 
-      coordinator.perform('Foo', [10, 20])
+      it 'performs a background migration with the configured shared connection' do
+        expect(coordinator).to receive(:with_shared_connection).and_call_original
+
+        expect_next_instance_of(migration_class) do |migration|
+          expect(migration).to receive(:perform).with(10, 20).once do
+            expect(Gitlab::Database::SharedModel.connection).to be(connection)
+          end
+        end
+
+        coordinator.perform('Foo', [10, 20])
+      end
+    end
+
+    context 'when the background migration inherits from BaseJob' do
+      let(:migration_class) { Class.new(::Gitlab::BackgroundMigration::BaseJob) }
+      let(:migration) { double(:migration) }
+
+      before do
+        stub_const('Gitlab::BackgroundMigration::Foo', migration_class)
+      end
+
+      it 'passes the correct connection when constructing the migration' do
+        expect(coordinator).to receive(:with_shared_connection).and_call_original
+
+        expect(migration_class).to receive(:new).with(connection: connection).and_return(migration)
+        expect(migration).to receive(:perform).with(10, 20).once do
+          expect(Gitlab::Database::SharedModel.connection).to be(connection)
+        end
+
+        coordinator.perform('Foo', [10, 20])
+      end
     end
   end
 
diff --git a/spec/lib/gitlab/database/background_migration_job_spec.rb b/spec/lib/gitlab/database/background_migration_job_spec.rb
index 42695925a1c..1117c17c84a 100644
--- a/spec/lib/gitlab/database/background_migration_job_spec.rb
+++ b/spec/lib/gitlab/database/background_migration_job_spec.rb
@@ -5,6 +5,8 @@ require 'spec_helper'
 RSpec.describe Gitlab::Database::BackgroundMigrationJob do
   it_behaves_like 'having unique enum values'
 
+  it { is_expected.to be_a Gitlab::Database::SharedModel }
+
   describe '.for_migration_execution' do
     let!(:job1) { create(:background_migration_job) }
     let!(:job2) { create(:background_migration_job, arguments: ['hi', 2]) }
diff --git a/spec/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table_spec.rb b/spec/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table_spec.rb
index c43b51e10a0..3072c413246 100644
--- a/spec/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table_spec.rb
+++ b/spec/lib/gitlab/database/partitioning_migration_helpers/backfill_partitioned_table_spec.rb
@@ -3,14 +3,15 @@
 require 'spec_helper'
 
 RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartitionedTable, '#perform' do
-  subject { described_class.new }
+  subject(:backfill_job) { described_class.new(connection: connection) }
 
+  let(:connection) { ActiveRecord::Base.connection }
   let(:source_table) { '_test_partitioning_backfills' }
   let(:destination_table) { "#{source_table}_part" }
   let(:unique_key) { 'id' }
 
   before do
-    allow(subject).to receive(:transaction_open?).and_return(false)
+    allow(backfill_job).to receive(:transaction_open?).and_return(false)
   end
 
   context 'when the destination table exists' do
@@ -50,10 +51,9 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
       stub_const("#{described_class}::SUB_BATCH_SIZE", 2)
       stub_const("#{described_class}::PAUSE_SECONDS", pause_seconds)
 
-      allow(subject).to receive(:sleep)
+      allow(backfill_job).to receive(:sleep)
     end
 
-    let(:connection) { ActiveRecord::Base.connection }
     let(:source_model) { Class.new(ActiveRecord::Base) }
     let(:destination_model) { Class.new(ActiveRecord::Base) }
     let(:timestamp) { Time.utc(2020, 1, 2).round }
@@ -66,7 +66,7 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
     it 'copies data into the destination table idempotently' do
       expect(destination_model.count).to eq(0)
 
-      subject.perform(source1.id, source3.id, source_table, destination_table, unique_key)
+      backfill_job.perform(source1.id, source3.id, source_table, destination_table, unique_key)
 
       expect(destination_model.count).to eq(3)
 
@@ -76,7 +76,7 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
         expect(destination_record.attributes).to eq(source_record.attributes)
       end
 
-      subject.perform(source1.id, source3.id, source_table, destination_table, unique_key)
+      backfill_job.perform(source1.id, source3.id, source_table, destination_table, unique_key)
 
       expect(destination_model.count).to eq(3)
     end
@@ -87,13 +87,13 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
         expect(bulk_copy).to receive(:copy_between).with(source3.id, source3.id)
       end
 
-      subject.perform(source1.id, source3.id, source_table, destination_table, unique_key)
+      backfill_job.perform(source1.id, source3.id, source_table, destination_table, unique_key)
     end
 
     it 'pauses after copying each sub-batch' do
-      expect(subject).to receive(:sleep).with(pause_seconds).twice
+      expect(backfill_job).to receive(:sleep).with(pause_seconds).twice
 
-      subject.perform(source1.id, source3.id, source_table, destination_table, unique_key)
+      backfill_job.perform(source1.id, source3.id, source_table, destination_table, unique_key)
     end
 
     it 'marks each job record as succeeded after processing' do
@@ -103,7 +103,7 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
       expect(::Gitlab::Database::BackgroundMigrationJob).to receive(:mark_all_as_succeeded).and_call_original
 
       expect do
-        subject.perform(source1.id, source3.id, source_table, destination_table, unique_key)
+        backfill_job.perform(source1.id, source3.id, source_table, destination_table, unique_key)
       end.to change { ::Gitlab::Database::BackgroundMigrationJob.succeeded.count }.from(0).to(1)
     end
 
@@ -111,24 +111,24 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
       create(:background_migration_job, class_name: "::#{described_class.name}",
         arguments: [source1.id, source3.id, source_table, destination_table, unique_key])
 
-      jobs_updated = subject.perform(source1.id, source3.id, source_table, destination_table, unique_key)
+      jobs_updated = backfill_job.perform(source1.id, source3.id, source_table, destination_table, unique_key)
 
       expect(jobs_updated).to eq(1)
     end
 
     context 'when the job is run within an explicit transaction block' do
+      subject(:backfill_job) { described_class.new(connection: mock_connection) }
+
       let(:mock_connection) { double('connection') }
 
-      before do
-        allow(subject).to receive(:connection).and_return(mock_connection)
-        allow(subject).to receive(:transaction_open?).and_return(true)
-      end
-
       it 'raises an error before copying data' do
+        expect(backfill_job).to receive(:transaction_open?).and_call_original
+
+        expect(mock_connection).to receive(:transaction_open?).and_return(true)
         expect(mock_connection).not_to receive(:execute)
 
         expect do
-          subject.perform(1, 100, source_table, destination_table, unique_key)
+          backfill_job.perform(1, 100, source_table, destination_table, unique_key)
         end.to raise_error(/Aborting job to backfill partitioned #{source_table}/)
 
         expect(destination_model.count).to eq(0)
@@ -137,24 +137,25 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::BackfillPartition
   end
 
   context 'when the destination table does not exist' do
+    subject(:backfill_job) { described_class.new(connection: mock_connection) }
+
     let(:mock_connection) { double('connection') }
     let(:mock_logger) { double('logger') }
 
     before do
-      allow(subject).to receive(:connection).and_return(mock_connection)
-      allow(subject).to receive(:logger).and_return(mock_logger)
-
-      expect(mock_connection).to receive(:table_exists?).with(destination_table).and_return(false)
+      allow(backfill_job).to receive(:logger).and_return(mock_logger)
       allow(mock_logger).to receive(:warn)
     end
 
     it 'exits without attempting to copy data' do
+      expect(mock_connection).to receive(:table_exists?).with(destination_table).and_return(false)
       expect(mock_connection).not_to receive(:execute)
 
       subject.perform(1, 100, source_table, destination_table, unique_key)
     end
 
     it 'logs a warning message that the job was skipped' do
+      expect(mock_connection).to receive(:table_exists?).with(destination_table).and_return(false)
       expect(mock_logger).to receive(:warn).with(/#{destination_table} does not exist/)
 
       subject.perform(1, 100, source_table, destination_table, unique_key)