Remove the ClearDatabaseCacheWorker

app/models/concerns/cache_markdown_field.rb

@@ -30,28 +30,6 @@ module CacheMarkdownField
     end
   end
 
-  # Dynamic registries don't really work in Rails as it's not guaranteed that
-  # every class will be loaded, so hardcode the list.
-  CACHING_CLASSES = %w[
-    AbuseReport
-    Appearance
-    ApplicationSetting
-    BroadcastMessage
-    Issue
-    Label
-    MergeRequest
-    Milestone
-    Namespace
-    Note
-    Project
-    Release
-    Snippet
-  ].freeze
-
-  def self.caching_classes
-    CACHING_CLASSES.map(&:constantize)
-  end
-
   def skip_project_check?
     false
   end
@@ -107,9 +85,6 @@ module CacheMarkdownField
     # a corresponding _html field. Any custom rendering options may be provided
     # as a context.
     def cache_markdown_field(markdown_field, context = {})
-      raise "Add #{self} to CacheMarkdownField::CACHING_CLASSES" unless
-        CacheMarkdownField::CACHING_CLASSES.include?(self.to_s)
-
       cached_markdown_fields[markdown_field] = context
 
       html_field = cached_markdown_fields.html_field(markdown_field)

app/workers/clear_database_cache_worker.rb

-# This worker clears all cache fields in the database, working in batches.
-class ClearDatabaseCacheWorker
-  include Sidekiq::Worker
-  include DedicatedSidekiqQueue
-
-  BATCH_SIZE = 1000
-
-  def perform
-    CacheMarkdownField.caching_classes.each do |kls|
-      fields = kls.cached_markdown_fields.html_fields
-      clear_cache_fields = fields.each_with_object({}) do |field, memo|
-        memo[field] = nil
-      end
-
-      Rails.logger.debug("Clearing Markdown cache for #{kls}: #{fields.inspect}")
-
-      kls.unscoped.in_batches(of: BATCH_SIZE) do |relation|
-        relation.update_all(clear_cache_fields)
-      end
-    end
-
-    nil
-  end
-end

config/sidekiq_queues.yml

@@ -34,7 +34,6 @@
   - [repository_fork, 1]
   - [repository_import, 1]
   - [project_service, 1]
-  - [clear_database_cache, 1]
   - [delete_user, 1]
   - [delete_merged_branches, 1]
   - [authorized_projects, 1]

lib/tasks/cache.rake

@@ -21,12 +21,7 @@ namespace :cache do
       end
     end
 
-    desc "GitLab | Clear database cache (in the background)"
-    task db: :environment do
-      ClearDatabaseCacheWorker.perform_async
-    end
-
-    task all: [:db, :redis]
+    task all: [:redis]
   end
 
   task clear: 'cache:clear:redis'

spec/models/concerns/cache_markdown_field_spec.rb

 require 'spec_helper'
 
 describe CacheMarkdownField do
-  caching_classes = CacheMarkdownField::CACHING_CLASSES
-  CacheMarkdownField::CACHING_CLASSES = ["ThingWithMarkdownFields"].freeze
-
   # The minimum necessary ActiveModel to test this concern
   class ThingWithMarkdownFields
     include ActiveModel::Model
@@ -55,8 +52,6 @@ describe CacheMarkdownField do
     end
   end
 
-  CacheMarkdownField::CACHING_CLASSES = caching_classes
-
   def thing_subclass(new_attr)
     Class.new(ThingWithMarkdownFields) { add_attr(new_attr) }
   end
@@ -69,15 +64,9 @@ describe CacheMarkdownField do
 
   subject { ThingWithMarkdownFields.new(foo: markdown, foo_html: html) }
 
-  describe ".attributes" do
-    it "excludes cache attributes" do
-      expect(thing_subclass(:qux).new.attributes.keys.sort).to eq(%w[bar baz foo qux])
-    end
-  end
-
-  describe ".cache_markdown_field" do
-    it "refuses to allow untracked classes" do
-      expect { thing_subclass(:qux).__send__(:cache_markdown_field, :qux) }.to raise_error(RuntimeError)
+  describe '.attributes' do
+    it 'excludes cache attributes' do
+      expect(subject.attributes.keys.sort).to eq(%w[bar baz foo])
     end
   end