Add support for feature flag type Ops

This flag represents ops type of features.

The purpose of `ops` is to have a long-lived
feature flags that might affect performance
of application.

app/services/concerns/measurable.rb

@@ -45,7 +45,7 @@ module Measurable
   private
 
   def measuring?
-    Feature.enabled?("gitlab_service_measuring_#{service_class}")
+    Feature.enabled?("gitlab_service_measuring_#{service_class}", type: :ops)
   end
 
   # These attributes are always present in log.

doc/development/feature_flags/development.md

@@ -25,9 +25,7 @@ This document is the subject of continued work as part of an epic to [improve in
 
 ## Types of feature flags
 
-Currently, only a single type of feature flag is available.
-Additional feature flag types will be provided in the future,
-with descriptions for their usage.
+Choose a feature flag type that matches the expected usage.
 
 ### `development` type
 
@@ -40,6 +38,29 @@ ideally created using the [Feature Flag Roll Out template](https://gitlab.com/gi
 NOTE: **Note:**
 This is the default type used when calling `Feature.enabled?`.
 
+### `ops` type
+
+`ops` feature flags are long-lived feature flags that control operational aspects
+of GitLab's behavior. For example, feature flags that disable features that might
+have a performance impact, like special Sidekiq worker behavior.
+
+`ops` feature flags likely do not have rollout issues, as it is hard to
+predict when they will be enabled or disabled.
+
+To use `ops` feature flags, you must append `type: :ops` to `Feature.enabled?`
+invocations:
+
+```ruby
+# Check if feature flag is enabled
+Feature.enabled?(:my_ops_flag, project, type: ops)
+
+# Check if feature flag is disabled
+Feature.disabled?(:my_ops_flag, project, type: ops)
+
+# Push feature flag to Frontend
+push_frontend_feature_flag(:my_ops_flag, project, type: :ops)
+```
+
 ## Feature flag definition and validation
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/229161) in GitLab 13.3.
@@ -147,6 +168,21 @@ if Feature.disabled?(:my_feature_flag, project, default_enabled: true)
 end
 ```
 
+If not specified, the default feature flag type for `Feature.enabled?` and `Feature.disabled?`
+is `type: development`. For all other feature flag types, you must specify the `type:`:
+
+```ruby
+if Feature.enabled?(:feature_flag, project, type: :ops)
+  # execute code if ops feature flag is enabled
+else
+  # execute code if ops feature flag is disabled
+end
+
+if Feature.disabled?(:my_feature_flag, project, type: :ops)
+  # execute code if feature flag is disabled
+end
+```
+
 ### Frontend
 
 Use the `push_frontend_feature_flag` method for frontend code, which is
@@ -192,6 +228,15 @@ before_action do
 end
 ```
 
+If not specified, the default feature flag type for `push_frontend_feature_flag`
+is `type: development`. For all other feature flag types, you must specify the `type:`:
+
+```ruby
+before_action do
+  push_frontend_feature_flag(:vim_bindings, project, type: :ops)
+end
+```
+
 ### Feature actors
 
 **It is strongly advised to use actors with feature flags.** Actors provide a simple

lib/feature/shared.rb

@@ -15,8 +15,18 @@ class Feature
         optional: true,
         rollout_issue: true,
         example: <<-EOS
-          Feature.enabled?(:my_feature_flag)
-          Feature.enabled?(:my_feature_flag, type: :development)
+          Feature.enabled?(:my_feature_flag, project)
+          Feature.enabled?(:my_feature_flag, project, type: :development)
+          push_frontend_feature_flag?(:my_feature_flag, project)
+        EOS
+      },
+      ops: {
+        description: "Long-lived feature flags that control operational aspects of GitLab's behavior",
+        optional: true,
+        rollout_issue: false,
+        example: <<-EOS
+          Feature.enabled?(:my_ops_flag, type: ops)
+          push_frontend_feature_flag?(:my_ops_flag, project, type: :ops)
         EOS
       }
     }.freeze

lib/gitlab/metrics/methods.rb

@@ -52,7 +52,7 @@ module Gitlab
         end
 
         def disabled_by_feature(options)
-          options.with_feature && !::Feature.enabled?(options.with_feature)
+          options.with_feature && !::Feature.enabled?(options.with_feature, type: :ops)
         end
 
         def build_metric!(type, name, options)

lib/gitlab/sidekiq_middleware/duplicate_jobs/duplicate_job.rb

@@ -71,7 +71,7 @@ module Gitlab
         end
 
         def droppable?
-          idempotent? && ::Feature.disabled?("disable_#{queue_name}_deduplication")
+          idempotent? && ::Feature.disabled?("disable_#{queue_name}_deduplication", type: :ops)
         end
 
         def scheduled_at