6 files changed, 97 insertions, 22 deletions
diff --git a/doc/administration/monitoring/gitlab_self_monitoring_project/index.md b/doc/administration/monitoring/gitlab_self_monitoring_project/index.md
index 1946e55603c..6f9821f4ace 100644
--- a/doc/administration/monitoring/gitlab_self_monitoring_project/index.md
+++ b/doc/administration/monitoring/gitlab_self_monitoring_project/index.md
@@ -17,7 +17,7 @@ members to the group in order to give them maintainer access to the project.
 
 This project will be used for self monitoring your GitLab instance.
 
-## Activating the self monitoring project
+## Creating the self monitoring project
 
 1. Navigate to **Admin Area > Settings > Metrics and profiling**, and expand the **Self monitoring** section.
 1. Toggle the **Create Project** button on.
@@ -26,10 +26,11 @@ created, GitLab displays a message with a link to the project. The project
 will also be linked in the help text above the **Create Project** button. You can also
 find the project under **Projects > Your projects**.
 
-## Deactivating the self monitoring project
+## Deleting the self monitoring project
 
 CAUTION: **Warning:**
-If you deactivate the self monitoring project, it will be permanently deleted.
+If you delete the self monitoring project, you will lose any changes made to the
+project. If you create the project again, it will be created in its default state.
 
 1. Navigate to **Admin Area > Settings > Metrics and profiling**, and expand the **Self monitoring** section.
 1. Toggle the **Create Project** button off.
diff --git a/doc/administration/operations/extra_sidekiq_processes.md b/doc/administration/operations/extra_sidekiq_processes.md
index 3ad411f6f5a..f859db5caff 100644
--- a/doc/administration/operations/extra_sidekiq_processes.md
+++ b/doc/administration/operations/extra_sidekiq_processes.md
@@ -53,6 +53,20 @@ To start extra Sidekiq processes, you must enable `sidekiq-cluster`:
    ]
    ```
 
+   [In GitLab 12.9](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/26594) and
+   later, the special queue name `*` means all queues. This starts two
+   processes, each handling all queues:
+
+   ```ruby
+   sidekiq_cluster['queue_groups'] = [
+     "*",
+     "*"
+   ]
+   ```
+
+   `*` cannot be combined with concrete queue names - `*, mailers` will
+   just handle the `mailers` queue.
+
 1. Save the file and reconfigure GitLab for the changes to take effect:
 
    ```shell
@@ -154,6 +168,10 @@ from highest to lowest precedence:
 The operator precedence for this syntax is fixed: it's not possible to make AND
 have higher precedence than OR.
 
+[In GitLab 12.9](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/26594) and
+later, as with the standard queue group syntax above, a single `*` as the
+entire queue group selects all queues.
+
 ### Example queries
 
 In `/etc/gitlab/gitlab.rb`:
@@ -163,9 +181,11 @@ sidekiq_cluster['enable'] = true
 sidekiq_cluster['experimental_queue_selector'] = true
 sidekiq_cluster['queue_groups'] = [
   # Run all non-CPU-bound queues that are high urgency
-  'resource_boundary!=cpu&urgency=high,
+  'resource_boundary!=cpu&urgency=high',
   # Run all continuous integration and pages queues that are not high urgency
-  'feature_category=continuous_integration,pages&urgency!=high
+  'feature_category=continuous_integration,pages&urgency!=high',
+  # Run all queues
+  '*'
 ]
 ```
 
diff --git a/doc/administration/troubleshooting/sidekiq.md b/doc/administration/troubleshooting/sidekiq.md
index b72bce5b3c6..8176ebab2e8 100644
--- a/doc/administration/troubleshooting/sidekiq.md
+++ b/doc/administration/troubleshooting/sidekiq.md
@@ -18,6 +18,26 @@ troubleshooting steps that will help you diagnose the bottleneck.
 > may be using all available CPU, or have a Ruby Global Interpreter Lock,
 > preventing other threads from continuing.
 
+## Log arguments to Sidekiq jobs
+
+If you want to see what arguments are being passed to Sidekiq jobs you can set
+the `SIDEKIQ_LOG_ARGUMENTS` [environment variable](https://docs.gitlab.com/omnibus/settings/environment-variables.html) to `1` (true).
+
+Example:
+
+```
+gitlab_rails['env'] = {"SIDEKIQ_LOG_ARGUMENTS" => "1"}
+```
+
+Please note: It is not recommend to enable this setting in production because some
+Sidekiq jobs (such as sending a password reset email) take secret arguments (for
+example the password reset token).
+
+When using [Sidekiq JSON logging](../logs.md#sidekiqlog),
+arguments logs are limited to a maximum size of 10 kilobytes of text;
+any arguments after this limit will be discarded and replaced with a
+single argument containing the string `"..."`.
+
 ## Thread dump
 
 Send the Sidekiq process ID the `TTIN` signal and it will output thread
diff --git a/doc/ci/yaml/README.md b/doc/ci/yaml/README.md
index 00b5d5d0d6d..9976a423996 100644
--- a/doc/ci/yaml/README.md
+++ b/doc/ci/yaml/README.md
@@ -158,6 +158,42 @@ rspec 2.6:
   script: bundle exec rspec
 ```
 
+### `inherit`
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/207484) in GitLab 12.9.
+
+You can disable inheritance of globally defined defaults
+and variables with the `inherit:` parameter.
+
+In the example below:
+
+- `rubocop` **will** inherit both the `before_script` and the variable `DOMAIN`.
+- `rspec` **will not** inherit the `before_script` or the variable `DOMAIN`.
+- `capybara` **will** inherit the `before_script`, but **will not** inherit the variable `DOMAIN`.
+
+```yaml
+default:
+  before_script:
+    - echo Hello World
+
+variables:
+  DOMAIN: example.com
+
+rubocop:
+  script: bundle exec rubocop
+
+rspec:
+  inherit:
+    default: false
+    variables: false
+  script: bundle exec rspec
+
+capybara:
+  inherit:
+    variables: false
+  script: bundle exec capybara
+```
+
 ## Parameter details
 
 The following are detailed explanations for parameters used to configure CI/CD pipelines.
diff --git a/doc/development/profiling.md b/doc/development/profiling.md
index 316273f37b8..04713055117 100644
--- a/doc/development/profiling.md
+++ b/doc/development/profiling.md
@@ -120,3 +120,16 @@ Bullet will log query problems to both the Rails log as well as the Chrome
 console.
 
 As a follow up to finding `N+1` queries with Bullet, consider writing a [QueryRecoder test](query_recorder.md) to prevent a regression.
+
+## Settings that impact performance
+
+1. `development` environment by default works with hot-reloading enabled, this makes Rails to check file changes every request, and create a potential contention lock, as hot reload is single threaded.
+1. `development` environment can load code lazily once the request is fired which results in first request to always be slow.
+
+To disable those features for profiling/benchmarking set the `RAILS_PROFILE` environment variable to `true` before starting GitLab. For example when using GDK:
+
+- create a file [`env.runit`](https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/master/doc/runit.md#modifying-environment-configuration-for-services) in the root GDK directory
+- add `export RAILS_PROFILE=true` to your `env.runit` file
+- restart GDK with `gdk restart`
+
+*This environment variable is only applicable for the development mode.*
diff --git a/doc/development/sidekiq_debugging.md b/doc/development/sidekiq_debugging.md
index 2b3a9481b93..b6a11dd813d 100644
--- a/doc/development/sidekiq_debugging.md
+++ b/doc/development/sidekiq_debugging.md
@@ -2,20 +2,5 @@
 
 ## Log arguments to Sidekiq jobs
 
-If you want to see what arguments are being passed to Sidekiq jobs you can set
-the `SIDEKIQ_LOG_ARGUMENTS` [environment variable](https://docs.gitlab.com/omnibus/settings/environment-variables.html) to `1` (true).
-
-Example:
-
-```
-gitlab_rails['env'] = {"SIDEKIQ_LOG_ARGUMENTS" => "1"}
-```
-
-Please note: It is not recommend to enable this setting in production because some
-Sidekiq jobs (such as sending a password reset email) take secret arguments (for
-example the password reset token).
-
-When using [Sidekiq JSON logging](../administration/logs.md#sidekiqlog),
-arguments logs are limited to a maximum size of 10 kilobytes of text;
-any arguments after this limit will be discarded and replaced with a
-single argument containing the string `"..."`.
+This content has been moved to the
+[Troubleshooting Sidekiq docs](../administration/troubleshooting/sidekiq.md).