diff --git a/.markdownlint.yml b/.markdownlint.yml
index 4e852880d26..dd04406f68d 100644
--- a/.markdownlint.yml
+++ b/.markdownlint.yml
@@ -130,7 +130,6 @@
     "Ubuntu",
     "Ultra Auth",
     "Unicorn",
-    "unicorn-worker-killer",
     "URL",
     "WebdriverIO",
     "YAML",
diff --git a/Gemfile b/Gemfile
index 018bf5fbcbe..25fb430c290 100644
--- a/Gemfile
+++ b/Gemfile
@@ -185,7 +185,6 @@ gem 'rack-timeout', '~> 0.5.1', require: 'rack/timeout/base'
 
 group :unicorn do
   gem 'unicorn', '~> 5.5'
-  gem 'unicorn-worker-killer', '~> 0.4.4'
 end
 
 group :puma do
diff --git a/Gemfile.lock b/Gemfile.lock
index c70f1710d50..62f5eb4d3a9 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1318,9 +1318,6 @@ GEM
     unicorn (5.5.5)
       kgio (~> 2.6)
       raindrops (~> 0.7)
-    unicorn-worker-killer (0.4.4)
-      get_process_mem (~> 0)
-      unicorn (>= 4, < 6)
     uniform_notifier (1.13.0)
     unleash (0.1.5)
       murmurhash3 (~> 0.1.6)
@@ -1653,7 +1650,6 @@ DEPENDENCIES
   u2f (~> 0.2.1)
   unf (~> 0.1.4)
   unicorn (~> 5.5)
-  unicorn-worker-killer (~> 0.4.4)
   unleash (~> 0.1.5)
   valid_email (~> 0.1)
   validates_hostname (~> 1.0.11)
diff --git a/app/assets/javascripts/blob/components/table_contents.vue b/app/assets/javascripts/blob/components/table_contents.vue
index 3a0a385d494..78ecb82f2cd 100644
--- a/app/assets/javascripts/blob/components/table_contents.vue
+++ b/app/assets/javascripts/blob/components/table_contents.vue
@@ -60,7 +60,7 @@ export default {
 </script>
 
 <template>
-  <gl-dropdown v-if="!isHidden && items.length" icon="list-bulleted" class="gl-mr-2">
+  <gl-dropdown v-if="!isHidden && items.length" icon="list-bulleted" class="gl-mr-2" lazy>
     <gl-dropdown-item v-for="(item, index) in items" :key="index" :href="`#${item.anchor}`">
       <span
         :style="{ 'padding-left': `${item.spacing}px` }"
diff --git a/app/assets/javascripts/boards/components/issue_time_estimate_deprecated.vue b/app/assets/javascripts/boards/components/issue_time_estimate_deprecated.vue
index fe56833016e..8ddf50cb357 100644
--- a/app/assets/javascripts/boards/components/issue_time_estimate_deprecated.vue
+++ b/app/assets/javascripts/boards/components/issue_time_estimate_deprecated.vue
@@ -10,7 +10,7 @@ export default {
   },
   props: {
     estimate: {
-      type: Number,
+      type: [Number, String],
       required: true,
     },
   },
diff --git a/app/assets/javascripts/performance_bar/components/performance_bar_app.vue b/app/assets/javascripts/performance_bar/components/performance_bar_app.vue
index ebe9c4eee2f..1bb847217d1 100644
--- a/app/assets/javascripts/performance_bar/components/performance_bar_app.vue
+++ b/app/assets/javascripts/performance_bar/components/performance_bar_app.vue
@@ -73,6 +73,11 @@ export default {
       header: s__('PerformanceBar|External Http calls'),
       keys: ['label', 'code', 'proxy', 'error'],
     },
+    {
+      metric: 'memory',
+      header: s__('PerformanceBar|Memory'),
+      keys: ['item_header', 'item_content'],
+    },
     {
       metric: 'total',
       header: s__('PerformanceBar|Frontend resources'),
diff --git a/app/views/projects/blob/_viewer.html.haml b/app/views/projects/blob/_viewer.html.haml
index a0d82ffd2c7..8713ce79d96 100644
--- a/app/views/projects/blob/_viewer.html.haml
+++ b/app/views/projects/blob/_viewer.html.haml
@@ -5,6 +5,7 @@
 - external_embed = local_assigns.fetch(:external_embed, false)
 
 - viewer_url = local_assigns.fetch(:viewer_url) { url_for(safe_params.merge(viewer: viewer.type, format: :json)) } if load_async
+- add_page_startup_api_call viewer_url
 .blob-viewer{ data: { type: viewer.type, rich_type: rich_type, url: viewer_url, path: viewer.blob.path }, class: ('hidden' if hidden) }
   - if render_error
     = render 'projects/blob/render_error', viewer: viewer
diff --git a/config.ru b/config.ru
index 0c50b3fdf6f..ed76239ef2e 100644
--- a/config.ru
+++ b/config.ru
@@ -2,25 +2,10 @@
 
 # This file is used by Rack-based servers to start the application.
 
-if defined?(Unicorn)
-  require 'unicorn'
-
-  if ENV['RAILS_ENV'] == 'production' || ENV['RAILS_ENV'] == 'staging'
-    # Unicorn self-process killer
-    require 'unicorn/worker_killer'
-
-    min = (ENV['GITLAB_UNICORN_MEMORY_MIN'] || 400 * 1 << 20).to_i
-    max = (ENV['GITLAB_UNICORN_MEMORY_MAX'] || 650 * 1 << 20).to_i
-
-    # Max memory size (RSS) per worker
-    use Unicorn::WorkerKiller::Oom, min, max
-  end
-end
-
 require ::File.expand_path('../config/environment', __FILE__)
 
 def master_process?
-  Prometheus::PidProvider.worker_id.in? %w(unicorn_master puma_master)
+  Prometheus::PidProvider.worker_id == 'puma_master'
 end
 
 warmup do |app|
diff --git a/config/dependency_decisions.yml b/config/dependency_decisions.yml
index 774254d2ff1..d76dd8fe25b 100644
--- a/config/dependency_decisions.yml
+++ b/config/dependency_decisions.yml
@@ -130,13 +130,6 @@
     :why: http://unicorn.bogomips.org/LICENSE.html
     :versions: []
     :when: 2016-05-02 05:45:28.817510000 Z
-- - :license
-  - unicorn-worker-killer
-  - ruby
-  - :who: Connor Shea
-    :why: https://github.com/kzk/unicorn-worker-killer/blob/master/LICENSE
-    :versions: []
-    :when: 2016-05-02 05:45:38.323867000 Z
 - - :license
   - unf
   - BSD
diff --git a/config/initializers/peek.rb b/config/initializers/peek.rb
index 85bfc4f0214..6fd92865731 100644
--- a/config/initializers/peek.rb
+++ b/config/initializers/peek.rb
@@ -15,9 +15,15 @@ Peek.into Peek::Views::Elasticsearch
 Peek.into Peek::Views::Rugged
 Peek.into Peek::Views::ExternalHttp
 Peek.into Peek::Views::BulletDetailed if defined?(Bullet)
+Peek.into Peek::Views::Memory
 
 Peek.into Peek::Views::Tracing if Labkit::Tracing.tracing_url_enabled?
 
+# Trigger view creation here, since views might be subscribing to Rails notifications
+# via setup_subscribers, which is called in the initializer.
+# See https://github.com/peek/peek/blob/master/lib/peek/views/view.rb
+Peek.views
+
 ActiveSupport::Notifications.subscribe('endpoint_run.grape') do |_name, _start, _finish, _id, payload|
   if request_id = payload[:env]['action_dispatch.request_id']
     Peek.adapter.save(request_id)
diff --git a/doc/administration/environment_variables.md b/doc/administration/environment_variables.md
index a168584e754..f98cddb52c9 100644
--- a/doc/administration/environment_variables.md
+++ b/doc/administration/environment_variables.md
@@ -32,8 +32,6 @@ You can use the following environment variables to override certain values:
 | `GITLAB_HOST`                              | string  | The full URL of the GitLab server (including `http://` or `https://`).                                  |
 | `GITLAB_ROOT_PASSWORD`                     | string  | Sets the password for the `root` user on installation.                                                  |
 | `GITLAB_SHARED_RUNNERS_REGISTRATION_TOKEN` | string  | Sets the initial registration token used for runners.                                                   |
-| `GITLAB_UNICORN_MEMORY_MAX`                | integer | The maximum memory threshold (in bytes) for the [unicorn-worker-killer](operations/unicorn.md#unicorn-worker-killer). |
-| `GITLAB_UNICORN_MEMORY_MIN`                | integer | The minimum memory threshold (in bytes) for the [unicorn-worker-killer](operations/unicorn.md#unicorn-worker-killer). |
 | `RAILS_ENV`                                | string  | The Rails environment; can be one of `production`, `development`, `staging`, or `test`.                 |
 | `UNSTRUCTURED_RAILS_LOG`                   | string  | Enables the unstructured log in addition to JSON logs (defaults to `true`).                             |
 
diff --git a/doc/administration/logs.md b/doc/administration/logs.md
index 8894f46aa26..5921406973b 100644
--- a/doc/administration/logs.md
+++ b/doc/administration/logs.md
@@ -611,41 +611,6 @@ This file lives in `/var/log/gitlab/puma/puma_stderr.log` for
 Omnibus GitLab packages, or in `/home/git/gitlab/log/puma_stderr.log` for
 installations from source.
 
-## Unicorn Logs
-
-Starting with GitLab 13.0, Puma is the default web server used in GitLab
-all-in-one package based installations, and GitLab Helm chart deployments.
-
-### `unicorn_stdout.log`
-
-This file lives in `/var/log/gitlab/unicorn/unicorn_stdout.log` for
-Omnibus GitLab packages or in `/home/git/gitlab/log/unicorn_stdout.log` for
-for installations from source.
-
-### `unicorn_stderr.log`
-
-This file lives in `/var/log/gitlab/unicorn/unicorn_stderr.log` for
-Omnibus GitLab packages or in `/home/git/gitlab/log/unicorn_stderr.log` for
-for installations from source.
-
-These logs contain all information about the state of Unicorn processes at any given time.
-
-```plaintext
-I, [2015-02-13T06:14:46.680381 #9047]  INFO -- : Refreshing Gem list
-I, [2015-02-13T06:14:56.931002 #9047]  INFO -- : listening on addr=127.0.0.1:8080 fd=12
-I, [2015-02-13T06:14:56.931381 #9047]  INFO -- : listening on addr=/var/opt/gitlab/gitlab-rails/sockets/gitlab.socket fd=13
-I, [2015-02-13T06:14:56.936638 #9047]  INFO -- : master process ready
-I, [2015-02-13T06:14:56.946504 #9092]  INFO -- : worker=0 spawned pid=9092
-I, [2015-02-13T06:14:56.946943 #9092]  INFO -- : worker=0 ready
-I, [2015-02-13T06:14:56.947892 #9094]  INFO -- : worker=1 spawned pid=9094
-I, [2015-02-13T06:14:56.948181 #9094]  INFO -- : worker=1 ready
-W, [2015-02-13T07:16:01.312916 #9094]  WARN -- : #<Unicorn::HttpServer:0x0000000208f618>: worker (pid: 9094) exceeds memory limit (320626688 bytes > 247066940 bytes)
-W, [2015-02-13T07:16:01.313000 #9094]  WARN -- : Unicorn::WorkerKiller send SIGQUIT (pid: 9094) alive: 3621 sec (trial 1)
-I, [2015-02-13T07:16:01.530733 #9047]  INFO -- : reaped #<Process::Status: pid 9094 exit 0> worker=1
-I, [2015-02-13T07:16:01.534501 #13379]  INFO -- : worker=1 spawned pid=13379
-I, [2015-02-13T07:16:01.534848 #13379]  INFO -- : worker=1 ready
-```
-
 ## `repocheck.log`
 
 This file lives in `/var/log/gitlab/gitlab-rails/repocheck.log` for
diff --git a/doc/administration/monitoring/performance/performance_bar.md b/doc/administration/monitoring/performance/performance_bar.md
index 72ab536ceae..780e5b47fba 100644
--- a/doc/administration/monitoring/performance/performance_bar.md
+++ b/doc/administration/monitoring/performance/performance_bar.md
@@ -6,7 +6,8 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # Performance Bar **(FREE SELF)**
 
-> The **Stats** field [introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/271551) in GitLab SaaS 13.9.
+> The **Stats** field [introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/271551) in GitLab 13.9.
+> The **Memory** field [introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/330736) in GitLab 14.0.
 
 You can display the GitLab Performance Bar to see statistics for the performance
 of a page. When activated, it looks as follows:
@@ -40,9 +41,11 @@ From left to right, it displays:
     Time until something was visible to the user.
   - [**DomContentLoaded**](https://developers.google.com/web/fundamentals/performance/critical-rendering-path/measure-crp) Event.
   - **Total number of requests** the page loaded.
-- **Trace**: If Jaeger is integrated, **Trace** links to a Jaeger tracing page
+- **Memory**: the amount of memory consumed and objects allocated during the selected request.
+  Select it to display a window with more details.
+- **Trace**: if Jaeger is integrated, **Trace** links to a Jaeger tracing page
   with the current request's `correlation_id` included.
-- **+**: A link to add a request's details to the performance bar. The request
+- **+**: a link to add a request's details to the performance bar. The request
   can be added by its full URL (authenticated as the current user), or by the value of
   its `X-Request-Id` header.
 - **Download**: a link to download the raw JSON used to generate the Performance Bar reports.
@@ -52,6 +55,11 @@ From left to right, it displays:
 - **Stats** (optional): if the `GITLAB_PERFORMANCE_BAR_STATS_URL` environment variable is set,
   this URL is displayed in the bar. In GitLab 13.9 and later, used only in GitLab SaaS.
 
+NOTE:
+Not all indicators are available in all environments. For instance, the memory view
+requires to run Ruby with [specific patches](https://gitlab.com/gitlab-org/gitlab-build-images/-/blob/master/patches/ruby/2.7.2/thread-memory-allocations-2.7.patch) applied.
+When running GitLab locally using the GDK this is typically not the case and the memory view cannot be used.
+
 ## Request warnings
 
 Requests that exceed predefined limits display a warning **{warning}** icon and
diff --git a/doc/administration/operations/index.md b/doc/administration/operations/index.md
index 708861d8529..268c9281d87 100644
--- a/doc/administration/operations/index.md
+++ b/doc/administration/operations/index.md
@@ -22,7 +22,6 @@ Keep your GitLab instance up and running smoothly.
   to restart Sidekiq.
 - [Multiple Sidekiq processes](extra_sidekiq_processes.md): Configure multiple Sidekiq processes to ensure certain queues always have dedicated workers, no matter the number of jobs that need to be processed. **(FREE SELF)**
 - [Puma](puma.md): Understand Puma and puma-worker-killer.
-- [Unicorn](unicorn.md): Understand Unicorn and unicorn-worker-killer.
 - Speed up SSH operations by [Authorizing SSH users via a fast,
   indexed lookup to the GitLab database](fast_ssh_key_lookup.md), and/or
   by [doing away with user SSH keys stored on GitLab entirely in favor
diff --git a/doc/administration/operations/unicorn.md b/doc/administration/operations/unicorn.md
deleted file mode 100644
index 03995ee05ba..00000000000
--- a/doc/administration/operations/unicorn.md
+++ /dev/null
@@ -1,115 +0,0 @@
----
-stage: Enablement
-group: Distribution
-info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
----
-
-# Understanding Unicorn and unicorn-worker-killer
-
-NOTE:
-Starting with GitLab 13.0, Puma is the default web server used in GitLab
-all-in-one package based installations as well as GitLab Helm chart deployments.
-
-## Unicorn
-
-GitLab uses [Unicorn](https://yhbt.net/unicorn/), a pre-forking Ruby web
-server, to handle web requests (web browsers and Git HTTP clients). Unicorn is
-a daemon written in Ruby and C that can load and run a Ruby on Rails
-application; in our case the Rails application is GitLab Community Edition or
-GitLab Enterprise Edition.
-
-Unicorn has a multi-process architecture to make better use of available CPU
-cores (processes can run on different cores) and to have stronger fault
-tolerance (most failures stay isolated in only one process and cannot take down
-GitLab entirely). On startup, the Unicorn 'master' process loads a clean Ruby
-environment with the GitLab application code, and then spawns 'workers' which
-inherit this clean initial environment. The 'master' never handles any
-requests, that is left to the workers. The operating system network stack
-queues incoming requests and distributes them among the workers.
-
-In a perfect world, the master would spawn its pool of workers once, and then
-the workers handle incoming web requests one after another until the end of
-time. In reality, worker processes can crash or time out: if the master notices
-that a worker takes too long to handle a request it will terminate the worker
-process with SIGKILL ('kill -9'). No matter how the worker process ended, the
-master process will replace it with a new 'clean' process again. Unicorn is
-designed to be able to replace 'crashed' workers without dropping user
-requests.
-
-This is what a Unicorn worker timeout looks like in `unicorn_stderr.log`. The
-master process has PID 56227 below.
-
-```plaintext
-[2015-06-05T10:58:08.660325 #56227] ERROR -- : worker=10 PID:53009 timeout (61s > 60s), killing
-[2015-06-05T10:58:08.699360 #56227] ERROR -- : reaped #<Process::Status: pid 53009 SIGKILL (signal 9)> worker=10
-[2015-06-05T10:58:08.708141 #62538]  INFO -- : worker=10 spawned pid=62538
-[2015-06-05T10:58:08.708824 #62538]  INFO -- : worker=10 ready
-```
-
-### Tunable options
-
-The main tunable options for Unicorn are the number of worker processes and the
-request timeout after which the Unicorn master terminates a worker process.
-See the [Omnibus GitLab Unicorn settings
-documentation](https://docs.gitlab.com/omnibus/settings/unicorn.html)
-if you want to adjust these settings.
-
-## unicorn-worker-killer
-
-GitLab has memory leaks. These memory leaks manifest themselves in long-running
-processes, such as Unicorn workers. (The Unicorn master process is not known to
-leak memory, probably because it does not handle user requests.)
-
-To make these memory leaks manageable, GitLab comes with the
-[unicorn-worker-killer gem](https://github.com/kzk/unicorn-worker-killer). This
-gem [monkey-patches](https://en.wikipedia.org/wiki/Monkey_patch) the Unicorn
-workers to do a memory self-check after every 16 requests. If the memory of the
-Unicorn worker exceeds a pre-set limit then the worker process exits. The
-Unicorn master then automatically replaces the worker process.
-
-This is a robust way to handle memory leaks: Unicorn is designed to handle
-workers that 'crash' so no user requests will be dropped. The
-unicorn-worker-killer gem is designed to only terminate a worker process _in
-between requests_, so no user requests are affected. You can set the minimum and
-maximum memory threshold (in bytes) for the Unicorn worker killer by
-setting the following values `/etc/gitlab/gitlab.rb`:
-
-- For GitLab **12.7** and newer:
-
-  ```ruby
-  unicorn['worker_memory_limit_min'] = "1024 * 1 << 20"
-  unicorn['worker_memory_limit_max'] = "1280 * 1 << 20"
-  ```
-
-- For GitLab **12.6** and older:
-
-  ```ruby
-  unicorn['worker_memory_limit_min'] = "400 * 1 << 20"
-  unicorn['worker_memory_limit_max'] = "650 * 1 << 20"
-  ```
-
-Otherwise, you can set the `GITLAB_UNICORN_MEMORY_MIN` and `GITLAB_UNICORN_MEMORY_MAX`
-[environment variables](../environment_variables.md).
-
-This is what a Unicorn worker memory restart looks like in unicorn_stderr.log.
-You see that worker 4 (PID 125918) is inspecting itself and decides to exit.
-The threshold memory value was 254802235 bytes, about 250MB. With GitLab this
-threshold is a random value between 200 and 250 MB. The master process (PID
-117565) then reaps the worker process and spawns a new 'worker 4' with PID
-127549.
-
-```plaintext
-[2015-06-05T12:07:41.828374 #125918]  WARN -- : #<Unicorn::HttpServer:0x00000002734770>: worker (pid: 125918) exceeds memory limit (256413696 bytes > 254802235 bytes)
-[2015-06-05T12:07:41.828472 #125918]  WARN -- : Unicorn::WorkerKiller send SIGQUIT (pid: 125918) alive: 23 sec (trial 1)
-[2015-06-05T12:07:42.025916 #117565]  INFO -- : reaped #<Process::Status: pid 125918 exit 0> worker=4
-[2015-06-05T12:07:42.034527 #127549]  INFO -- : worker=4 spawned pid=127549
-[2015-06-05T12:07:42.035217 #127549]  INFO -- : worker=4 ready
-```
-
-One other thing that stands out in the log snippet above, taken from
-GitLab.com, is that 'worker 4' was serving requests for only 23 seconds. This
-is a normal value for our current GitLab.com setup and traffic.
-
-The high frequency of Unicorn memory restarts on some GitLab sites can be a
-source of confusion for administrators. Usually they are a [red
-herring](https://en.wikipedia.org/wiki/Red_herring).
diff --git a/doc/development/architecture.md b/doc/development/architecture.md
index fdcaa91a639..d8d452240ff 100644
--- a/doc/development/architecture.md
+++ b/doc/development/architecture.md
@@ -710,23 +710,6 @@ disabled by default.
 
 [Puma](https://puma.io/) is a Ruby application server that is used to run the core Rails Application that provides the user facing features in GitLab. Often this displays in process output as `bundle` or `config.ru` depending on the GitLab version.
 
-#### Unicorn
-
-Starting with GitLab 13.0, Puma is the default web server and Unicorn has been
-disabled by default.
-
-- [Project page](https://gitlab.com/gitlab-org/gitlab/blob/master/README.md)
-- Configuration:
-  - [Omnibus](https://docs.gitlab.com/omnibus/settings/unicorn.html)
-  - [Charts](https://docs.gitlab.com/charts/charts/gitlab/webservice/)
-  - [Source](../install/installation.md#configure-it)
-  - [GDK](https://gitlab.com/gitlab-org/gitlab/blob/master/config/gitlab.yml.example)
-- Layer: Core Service (Processor)
-- Process: `unicorn`
-- GitLab.com: [Unicorn](../user/gitlab_com/index.md#unicorn)
-
-[Unicorn](https://yhbt.net/unicorn/) is a Ruby application server that is used to run the core Rails Application that provides the user facing features in GitLab. Often this displays in process output as `bundle` or `config.ru` depending on the GitLab version.
-
 #### LDAP Authentication
 
 - Configuration:
diff --git a/doc/development/usage_ping/metrics_dictionary.md b/doc/development/usage_ping/metrics_dictionary.md
index 9fd09714e65..c888a9858a6 100644
--- a/doc/development/usage_ping/metrics_dictionary.md
+++ b/doc/development/usage_ping/metrics_dictionary.md
@@ -57,6 +57,18 @@ Metric definitions can have one of the following statuses:
 - `deprecated`: Metric is deprecated and possibly planned to be removed.
 - `removed`: Metric was removed, but it may appear in Usage Ping payloads sent from instances running on older versions of GitLab.
 
+### Metric value_type
+
+Metric definitions can have one of the following values for `value_type`:
+
+- `boolean`
+- `number`
+- `string`
+- `object`: A metric with `value_type: object` must have `value_json_schema` with a link to the JSON schema for the object.
+In general, we avoid complex objects and prefer one of the `boolean`, `number`, or `string` value types.
+An example of a metric that uses `value_type: object` is `topology` (`/config/metrics/settings/20210323120839_topology.yml`),
+which has a related schema in `/config/metrics/objects_schemas/topology_schema.json`.
+
 ### Metric name
 
 To improve metric discoverability by a wider audience, each metric with
diff --git a/doc/user/gitlab_com/index.md b/doc/user/gitlab_com/index.md
index cdb4ca52c9c..f05e5f00bc2 100644
--- a/doc/user/gitlab_com/index.md
+++ b/doc/user/gitlab_com/index.md
@@ -508,20 +508,6 @@ of proposed changes can be found at
 
 GitLab.com uses the default of 60 seconds for [Puma request timeouts](https://docs.gitlab.com/omnibus/settings/puma.html#worker-timeout).
 
-## Unicorn
-
-GitLab.com adjusts the memory limits for the [unicorn-worker-killer](https://rubygems.org/gems/unicorn-worker-killer) gem.
-
-Base default:
-
-- `memory_limit_min` = 750MiB
-- `memory_limit_max` = 1024MiB
-
-Web front-ends:
-
-- `memory_limit_min` = 1024MiB
-- `memory_limit_max` = 1280MiB
-
 ## GitLab.com-specific rate limits
 
 NOTE:
diff --git a/lib/peek/views/memory.rb b/lib/peek/views/memory.rb
new file mode 100644
index 00000000000..399474dedf1
--- /dev/null
+++ b/lib/peek/views/memory.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+module Peek
+  module Views
+    class Memory < View
+      MEM_TOTAL_LABEL = 'Total'
+      MEM_OBJECTS_LABEL = 'Objects allocated'
+      MEM_MALLOCS_LABEL = 'Allocator calls'
+      MEM_BYTES_LABEL = 'Large allocations'
+
+      def initialize(options = {})
+        super
+
+        @thread_memory = {}
+      end
+
+      def results
+        return thread_memory if thread_memory.empty?
+
+        {
+          calls: byte_string(thread_memory[:mem_total_bytes]),
+          summary: {
+            MEM_OBJECTS_LABEL => number_string(thread_memory[:mem_objects]),
+            MEM_MALLOCS_LABEL => number_string(thread_memory[:mem_mallocs]),
+            MEM_BYTES_LABEL => byte_string(thread_memory[:mem_bytes])
+          },
+          details: [
+            {
+              item_header: MEM_TOTAL_LABEL,
+              item_content: "Total memory use of this request. This includes both occupancy of existing heap slots " \
+                            "as well as newly allocated memory due to large objects. Not adjusted for freed memory. " \
+                            "Lower is better."
+            },
+            {
+              item_header: MEM_OBJECTS_LABEL,
+              item_content: "Total number of objects allocated by the Ruby VM during this request. " \
+                            "Not adjusted for objects that were freed again. Lower is better."
+            },
+            {
+              item_header: MEM_MALLOCS_LABEL,
+              item_content: "Total number of times Ruby had to call `malloc`, the C memory allocator. " \
+                            "This is necessary for objects that are too large to fit into a 40 Byte slot in Ruby's managed heap. " \
+                            "Lower is better."
+            },
+            {
+              item_header: MEM_BYTES_LABEL,
+              item_content: "Memory allocated for objects that did not fit into a heap slot. " \
+                            "Not adjusted for memory that was freed again. Lower is better."
+            }
+          ]
+        }
+      end
+
+      private
+
+      attr_reader :thread_memory
+
+      def setup_subscribers
+        subscribe 'process_action.action_controller' do
+          # Ensure that Peek will see memory instrumentation in `results` by triggering it when
+          # a request is done processing. Peek itself hooks into the same notification:
+          # https://github.com/peek/peek/blob/master/lib/peek/railtie.rb
+          Gitlab::InstrumentationHelper.instrument_thread_memory_allocations(thread_memory)
+        end
+      end
+
+      def byte_string(bytes)
+        ActiveSupport::NumberHelper.number_to_human_size(bytes)
+      end
+
+      def number_string(num)
+        ActiveSupport::NumberHelper.number_to_human(num, units: { thousand: 'k', million: 'M', billion: 'B' })
+      end
+    end
+  end
+end
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index c3ca3be623f..aadde55bfe4 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -6778,72 +6778,6 @@ msgstr ""
 msgid "Cloud licenses can not be removed."
 msgstr ""
 
-msgid "CloudLicense|Activate"
-msgstr ""
-
-msgid "CloudLicense|Activate subscription"
-msgstr ""
-
-msgid "CloudLicense|Activation code"
-msgstr ""
-
-msgid "CloudLicense|Billable users"
-msgstr ""
-
-msgid "CloudLicense|Buy subscription"
-msgstr ""
-
-msgid "CloudLicense|Enter activation code"
-msgstr ""
-
-msgid "CloudLicense|Free trial"
-msgstr ""
-
-msgid "CloudLicense|Get help for the most common connectivity issues by %{linkStart}troubleshooting the activation code%{linkEnd}."
-msgstr ""
-
-msgid "CloudLicense|I agree that my use of the GitLab Software is subject to the Subscription Agreement located at the %{linkStart}Terms of Service%{linkEnd}, unless otherwise agreed to in writing with GitLab."
-msgstr ""
-
-msgid "CloudLicense|Maximum users"
-msgstr ""
-
-msgid "CloudLicense|Paste your activation code"
-msgstr ""
-
-msgid "CloudLicense|Ready to get started? A GitLab plan is ideal for scaling organizations and for multi team usage."
-msgstr ""
-
-msgid "CloudLicense|Start free trial"
-msgstr ""
-
-msgid "CloudLicense|Subscription"
-msgstr ""
-
-msgid "CloudLicense|This is the highest peak of users on your installation since the license started."
-msgstr ""
-
-msgid "CloudLicense|This is the number of %{billableUsersLinkStart}billable users%{billableUsersLinkEnd} on your installation, and this is the minimum number you need to purchase when you renew your license."
-msgstr ""
-
-msgid "CloudLicense|To activate your subscription, connect to GitLab servers through the %{linkStart}Cloud Sync service%{linkEnd}, a hassle-free way to manage your subscription."
-msgstr ""
-
-msgid "CloudLicense|Users in subscription"
-msgstr ""
-
-msgid "CloudLicense|Users over subscription"
-msgstr ""
-
-msgid "CloudLicense|Users with a Guest role or those who don't belong to a Project or Group will not use a seat from your license."
-msgstr ""
-
-msgid "CloudLicense|You can start a free trial of GitLab Ultimate without any obligation or payment details."
-msgstr ""
-
-msgid "CloudLicense|You'll be charged for %{trueUpLinkStart}users over license%{trueUpLinkEnd} on a quarterly or annual basis, depending on the terms of your agreement."
-msgstr ""
-
 msgid "Cluster"
 msgstr ""
 
@@ -23973,6 +23907,9 @@ msgstr ""
 msgid "PerformanceBar|Gitaly calls"
 msgstr ""
 
+msgid "PerformanceBar|Memory"
+msgstr ""
+
 msgid "PerformanceBar|Redis calls"
 msgstr ""
 
@@ -31606,15 +31543,42 @@ msgstr ""
 msgid "Sunday"
 msgstr ""
 
+msgid "SuperSonics|Activate"
+msgstr ""
+
+msgid "SuperSonics|Activate subscription"
+msgstr ""
+
 msgid "SuperSonics|Activated on"
 msgstr ""
 
+msgid "SuperSonics|Activation code"
+msgstr ""
+
 msgid "SuperSonics|An error occurred while activating your subscription."
 msgstr ""
 
+msgid "SuperSonics|Billable users"
+msgstr ""
+
+msgid "SuperSonics|Buy subscription"
+msgstr ""
+
+msgid "SuperSonics|Enter activation code"
+msgstr ""
+
 msgid "SuperSonics|Expires on"
 msgstr ""
 
+msgid "SuperSonics|Free trial"
+msgstr ""
+
+msgid "SuperSonics|Get help for the most common connectivity issues by %{linkStart}troubleshooting the activation code%{linkEnd}."
+msgstr ""
+
+msgid "SuperSonics|I agree that my use of the GitLab Software is subject to the Subscription Agreement located at the %{linkStart}Terms of Service%{linkEnd}, unless otherwise agreed to in writing with GitLab."
+msgstr ""
+
 msgid "SuperSonics|ID"
 msgstr ""
 
@@ -31630,18 +31594,33 @@ msgstr ""
 msgid "SuperSonics|Manage"
 msgstr ""
 
+msgid "SuperSonics|Maximum users"
+msgstr ""
+
+msgid "SuperSonics|Paste your activation code"
+msgstr ""
+
 msgid "SuperSonics|Plan"
 msgstr ""
 
+msgid "SuperSonics|Ready to get started? A GitLab plan is ideal for scaling organizations and for multi team usage."
+msgstr ""
+
 msgid "SuperSonics|Renews"
 msgstr ""
 
 msgid "SuperSonics|Seats"
 msgstr ""
 
+msgid "SuperSonics|Start free trial"
+msgstr ""
+
 msgid "SuperSonics|Started"
 msgstr ""
 
+msgid "SuperSonics|Subscription"
+msgstr ""
+
 msgid "SuperSonics|Subscription details"
 msgstr ""
 
@@ -31657,21 +31636,45 @@ msgstr ""
 msgid "SuperSonics|This field is required."
 msgstr ""
 
+msgid "SuperSonics|This is the highest peak of users on your installation since the license started."
+msgstr ""
+
+msgid "SuperSonics|This is the number of %{billableUsersLinkStart}billable users%{billableUsersLinkEnd} on your installation, and this is the minimum number you need to purchase when you renew your license."
+msgstr ""
+
+msgid "SuperSonics|To activate your subscription, connect to GitLab servers through the %{linkStart}Cloud Licensing%{linkEnd} service, a hassle-free way to manage your subscription."
+msgstr ""
+
 msgid "SuperSonics|Type"
 msgstr ""
 
 msgid "SuperSonics|Upload a legacy license"
 msgstr ""
 
+msgid "SuperSonics|Users in subscription"
+msgstr ""
+
+msgid "SuperSonics|Users over subscription"
+msgstr ""
+
+msgid "SuperSonics|Users with a Guest role or those who don't belong to a Project or Group will not use a seat from your license."
+msgstr ""
+
 msgid "SuperSonics|Valid From"
 msgstr ""
 
 msgid "SuperSonics|You can no longer sync your subscription details with GitLab. Get help for the most common connectivity issues by %{connectivityHelpLinkStart}troubleshooting the activation code%{connectivityHelpLinkEnd}."
 msgstr ""
 
+msgid "SuperSonics|You can start a free trial of GitLab Ultimate without any obligation or payment details."
+msgstr ""
+
 msgid "SuperSonics|You do not have an active subscription"
 msgstr ""
 
+msgid "SuperSonics|You'll be charged for %{trueUpLinkStart}users over license%{trueUpLinkEnd} on a quarterly or annual basis, depending on the terms of your agreement."
+msgstr ""
+
 msgid "SuperSonics|Your subscription"
 msgstr ""
 
diff --git a/package.json b/package.json
index e5431b98689..2c2816edc98 100644
--- a/package.json
+++ b/package.json
@@ -101,7 +101,7 @@
     "codesandbox-api": "0.0.23",
     "compression-webpack-plugin": "^5.0.2",
     "copy-webpack-plugin": "^6.4.1",
-    "core-js": "^3.12.1",
+    "core-js": "^3.13.0",
     "cron-validator": "^1.1.1",
     "cropper": "^2.3.0",
     "css-loader": "^2.1.1",
@@ -193,7 +193,7 @@
     "@gitlab/eslint-plugin": "8.4.0",
     "@gitlab/stylelint-config": "2.3.0",
     "@testing-library/dom": "^7.16.2",
-    "@vue/test-utils": "1.1.2",
+    "@vue/test-utils": "1.2.0",
     "acorn": "^6.3.0",
     "axios-mock-adapter": "^1.15.0",
     "babel-jest": "^26.5.2",
diff --git a/spec/frontend/__helpers__/vue_test_utils_helper.js b/spec/frontend/__helpers__/vue_test_utils_helper.js
index a94cee84f74..2aae91f8a39 100644
--- a/spec/frontend/__helpers__/vue_test_utils_helper.js
+++ b/spec/frontend/__helpers__/vue_test_utils_helper.js
@@ -1,5 +1,5 @@
 import * as testingLibrary from '@testing-library/dom';
-import { createWrapper, WrapperArray, mount, shallowMount } from '@vue/test-utils';
+import { createWrapper, WrapperArray, ErrorWrapper, mount, shallowMount } from '@vue/test-utils';
 import { isArray, upperFirst } from 'lodash';
 
 const vNodeContainsText = (vnode, text) =>
@@ -81,14 +81,9 @@ export const extendedWrapper = (wrapper) => {
               options,
             );
 
-            // Return VTU `ErrorWrapper` if element is not found
-            // https://github.com/vuejs/vue-test-utils/blob/dev/packages/test-utils/src/error-wrapper.js
-            // VTU does not expose `ErrorWrapper` so, as of now, this is the best way to
-            // create an `ErrorWrapper`
+            // Element not found, return an `ErrorWrapper`
             if (!elements.length) {
-              const emptyElement = document.createElement('div');
-
-              return createWrapper(emptyElement).find('testing-library-element-not-found');
+              return new ErrorWrapper(query);
             }
 
             return createWrapper(elements[0], this.options || {});
diff --git a/spec/frontend/__helpers__/vue_test_utils_helper_spec.js b/spec/frontend/__helpers__/vue_test_utils_helper_spec.js
index dfe5a483223..3bb228f94b8 100644
--- a/spec/frontend/__helpers__/vue_test_utils_helper_spec.js
+++ b/spec/frontend/__helpers__/vue_test_utils_helper_spec.js
@@ -4,6 +4,7 @@ import {
   shallowMount,
   Wrapper as VTUWrapper,
   WrapperArray as VTUWrapperArray,
+  ErrorWrapper as VTUErrorWrapper,
 } from '@vue/test-utils';
 import {
   extendedWrapper,
@@ -195,7 +196,7 @@ describe('Vue test utils helpers', () => {
         });
 
         it('returns a VTU error wrapper', () => {
-          expect(wrapper[findMethod](text, options).exists()).toBe(false);
+          expect(wrapper[findMethod](text, options)).toBeInstanceOf(VTUErrorWrapper);
         });
       });
     });
diff --git a/spec/frontend/ide/components/repo_editor_spec.js b/spec/frontend/ide/components/repo_editor_spec.js
index 646e51160d8..41a93c7ba5a 100644
--- a/spec/frontend/ide/components/repo_editor_spec.js
+++ b/spec/frontend/ide/components/repo_editor_spec.js
@@ -656,7 +656,7 @@ describe('RepoEditor', () => {
     });
 
     it("does not add file to state or set markdown image syntax if the file isn't markdown", async () => {
-      wrapper.setProps({
+      await wrapper.setProps({
         file: setFileName('myfile.txt'),
       });
       pasteImage();
diff --git a/spec/frontend/notes/components/discussion_actions_spec.js b/spec/frontend/notes/components/discussion_actions_spec.js
index c6a7d7ead98..925dbcc09ec 100644
--- a/spec/frontend/notes/components/discussion_actions_spec.js
+++ b/spec/frontend/notes/components/discussion_actions_spec.js
@@ -20,7 +20,7 @@ const createUnallowedNote = () =>
 
 describe('DiscussionActions', () => {
   let wrapper;
-  const createComponentFactory = (shallow = true) => (props) => {
+  const createComponentFactory = (shallow = true) => (props, options) => {
     const store = createStore();
     const mountFn = shallow ? shallowMount : mount;
 
@@ -34,6 +34,7 @@ describe('DiscussionActions', () => {
         shouldShowJumpToNextDiscussion: true,
         ...props,
       },
+      ...options,
     });
   };
 
@@ -90,17 +91,17 @@ describe('DiscussionActions', () => {
   describe('events handling', () => {
     const createComponent = createComponentFactory(false);
 
-    beforeEach(() => {
-      createComponent();
-    });
-
     it('emits showReplyForm event when clicking on reply placeholder', () => {
+      createComponent({}, { attachTo: document.body });
+
       jest.spyOn(wrapper.vm, '$emit');
       wrapper.find(ReplyPlaceholder).find('textarea').trigger('focus');
       expect(wrapper.vm.$emit).toHaveBeenCalledWith('showReplyForm');
     });
 
     it('emits resolve event when clicking on resolve button', () => {
+      createComponent();
+
       jest.spyOn(wrapper.vm, '$emit');
       wrapper.find(ResolveDiscussionButton).find('button').trigger('click');
       expect(wrapper.vm.$emit).toHaveBeenCalledWith('resolve');
diff --git a/spec/frontend/notes/components/discussion_reply_placeholder_spec.js b/spec/frontend/notes/components/discussion_reply_placeholder_spec.js
index 2a4cd0df0c7..3932f818c4e 100644
--- a/spec/frontend/notes/components/discussion_reply_placeholder_spec.js
+++ b/spec/frontend/notes/components/discussion_reply_placeholder_spec.js
@@ -6,31 +6,34 @@ const placeholderText = 'Test Button Text';
 describe('ReplyPlaceholder', () => {
   let wrapper;
 
-  const findTextarea = () => wrapper.find({ ref: 'textarea' });
-
-  beforeEach(() => {
+  const createComponent = ({ options = {} } = {}) => {
     wrapper = shallowMount(ReplyPlaceholder, {
       propsData: {
         placeholderText,
       },
+      ...options,
     });
-  });
+  };
+
+  const findTextarea = () => wrapper.find({ ref: 'textarea' });
 
   afterEach(() => {
     wrapper.destroy();
   });
 
-  it('emits focus event on button click', () => {
-    findTextarea().trigger('focus');
+  it('emits focus event on button click', async () => {
+    createComponent({ options: { attachTo: document.body } });
 
-    return wrapper.vm.$nextTick().then(() => {
-      expect(wrapper.emitted()).toEqual({
-        focus: [[]],
-      });
+    await findTextarea().trigger('focus');
+
+    expect(wrapper.emitted()).toEqual({
+      focus: [[]],
     });
   });
 
   it('should render reply button', () => {
+    createComponent();
+
     expect(findTextarea().attributes('placeholder')).toEqual(placeholderText);
   });
 });
diff --git a/spec/frontend/pages/projects/graphs/__snapshots__/code_coverage_spec.js.snap b/spec/frontend/pages/projects/graphs/__snapshots__/code_coverage_spec.js.snap
index c4c48ea7517..4ba9120d196 100644
--- a/spec/frontend/pages/projects/graphs/__snapshots__/code_coverage_spec.js.snap
+++ b/spec/frontend/pages/projects/graphs/__snapshots__/code_coverage_spec.js.snap
@@ -66,7 +66,7 @@ exports[`Code Coverage when fetching data is successful matches the snapshot 1`]
   <gl-area-chart-stub
     annotations=""
     data="[object Object]"
-    formattooltiptext="function () { [native code] }"
+    formattooltiptext="[Function]"
     height="200"
     includelegendavgmax="true"
     legendaveragetext="Avg"
diff --git a/spec/lib/peek/views/memory_spec.rb b/spec/lib/peek/views/memory_spec.rb
new file mode 100644
index 00000000000..1f88aadfc54
--- /dev/null
+++ b/spec/lib/peek/views/memory_spec.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Peek::Views::Memory, :request_store do
+  subject! { described_class.new }
+
+  before do
+    stub_memory_instrumentation
+  end
+
+  context 'with process_action.action_controller notification' do
+    it 'returns empty results when it has not yet fired' do
+      expect(subject.results).to eq({})
+    end
+
+    it 'returns memory instrumentation data when it has fired' do
+      publish_notification
+
+      expect(subject.results[:calls]).to eq('2 MB')
+      expect(subject.results[:details]).to all(have_key(:item_header))
+      expect(subject.results[:details]).to all(have_key(:item_content))
+      expect(subject.results[:summary]).to include('Objects allocated' => '200 k')
+      expect(subject.results[:summary]).to include('Allocator calls' => '500')
+      expect(subject.results[:summary]).to include('Large allocations' => '1 KB')
+    end
+  end
+
+  def stub_memory_instrumentation
+    start_memory = {
+      total_malloc_bytes: 1,
+      total_mallocs: 2,
+      total_allocated_objects: 3
+    }
+    allow(Gitlab::Memory::Instrumentation).to receive(:start_thread_memory_allocations).and_return(start_memory)
+    allow(Gitlab::Memory::Instrumentation).to receive(:measure_thread_memory_allocations).with(start_memory).and_return({
+      mem_total_bytes: 2_097_152,
+      mem_bytes: 1024,
+      mem_mallocs: 500,
+      mem_objects: 200_000
+    })
+    Gitlab::InstrumentationHelper.init_instrumentation_data
+  end
+
+  def publish_notification
+    headers = double
+    allow(headers).to receive(:env).and_return('action_dispatch.request_id': 'req-42')
+
+    ActiveSupport::Notifications.publish(
+      'process_action.action_controller', Time.current - 1.second, Time.current, 'id', headers: headers
+    )
+  end
+end
diff --git a/yarn.lock b/yarn.lock
index 851d6618866..a0961053bbb 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1816,10 +1816,10 @@
     source-map "~0.6.1"
     vue-template-es2015-compiler "^1.9.0"
 
-"@vue/test-utils@1.1.2":
-  version "1.1.2"
-  resolved "https://registry.yarnpkg.com/@vue/test-utils/-/test-utils-1.1.2.tgz#fdb487448dceefeaf3d01d465f7c836a3d666dbc"
-  integrity sha512-utbIL7zn9c+SjhybPwh48lpWCiluFCbP1yyRNAy1fQsw/6hiNFioaWy05FoVAFIZXC5WwBf+5r4ypfM1j/nI4A==
+"@vue/test-utils@1.2.0":
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/@vue/test-utils/-/test-utils-1.2.0.tgz#3bc8c17ed549157275f0aec6b95da40887f7297f"
+  integrity sha512-poBTLqeJYNq1TXVhtVfnY8vELUVOFdJY8KZZoUuaAkIqPTWsxonU1M8nMWpZT+xEMrM+49+YcuEqtMHVD9Q9gw==
   dependencies:
     dom-event-types "^1.0.0"
     lodash "^4.17.15"
@@ -3606,10 +3606,10 @@ core-js-pure@^3.0.0:
   resolved "https://registry.yarnpkg.com/core-js-pure/-/core-js-pure-3.6.5.tgz#c79e75f5e38dbc85a662d91eea52b8256d53b813"
   integrity sha512-lacdXOimsiD0QyNf9BC/mxivNJ/ybBGJXQFKzRekp1WTHoVUWsUHEn+2T8GJAzzIhyOuXA+gOxCVN3l+5PLPUA==
 
-core-js@^3.1.3, core-js@^3.12.1:
-  version "3.12.1"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.12.1.tgz#6b5af4ff55616c08a44d386f1f510917ff204112"
-  integrity sha512-Ne9DKPHTObRuB09Dru5AjwKjY4cJHVGu+y5f7coGn1E9Grkc3p2iBwE9AI/nJzsE29mQF7oq+mhYYRqOMFN1Bw==
+core-js@^3.1.3, core-js@^3.13.0:
+  version "3.13.0"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.13.0.tgz#58ca436bf01d6903aee3d364089868d0d89fe58d"
+  integrity sha512-iWDbiyha1M5vFwPFmQnvRv+tJzGbFAm6XimJUT0NgHYW3xZEs1SkCAcasWSVFxpI2Xb/V1DDJckq3v90+bQnog==
 
 core-js@~2.3.0:
   version "2.3.0"