Remove soft removals related code

This removes all usage of soft removals except for the "pending delete"
system implemented for projects. This in turn simplifies all the query
plans of the models that used soft removals. Since we don't really use
soft removals for anything useful there's no point in keeping it around.

This _does_ mean that hard removals of issues (which only admins can do
if I'm not mistaken) can influence the "iid" values, but that code is
broken to begin with. More on this (and how to fix it) can be found in
https://gitlab.com/gitlab-org/gitlab-ce/issues/31114.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/37447

Gemfile

@@ -381,9 +381,6 @@ gem 'ruby-prof', '~> 0.16.2'
 # OAuth
 gem 'oauth2', '~> 1.4'
-# Soft deletion
-gem 'paranoia', '~> 2.3.1'
-
 # Health check
 gem 'health_check', '~> 2.6.0'

Gemfile.lock

@@ -580,8 +580,6 @@ GEM
     orm_adapter (0.5.0)
     os (0.9.6)
     parallel (1.12.0)
-    paranoia (2.3.1)
-      activerecord (>= 4.0, < 5.2)
     parser (2.4.0.2)
       ast (~> 2.3)
     parslet (1.5.0)
@@ -1110,7 +1108,6 @@ DEPENDENCIES
   omniauth-twitter (~> 1.2.0)
   omniauth_crowd (~> 2.2.0)
   org-ruby (~> 0.9.12)
-  paranoia (~> 2.3.1)
   peek (~> 1.0.1)
   peek-gc (~> 0.0.2)
   peek-host (~> 1.0.0)

app/models/ci/pipeline_schedule.rb

@@ -2,8 +2,9 @@ module Ci
   class PipelineSchedule < ActiveRecord::Base
     extend Gitlab::Ci::Model
     include Importable
-    acts_as_paranoid
+    include IgnorableColumn
+    ignore_column :deleted_at
     belongs_to :project
     belongs_to :owner, class_name: 'User'

app/models/ci/trigger.rb

 module Ci
   class Trigger < ActiveRecord::Base
     extend Gitlab::Ci::Model
-    acts_as_paranoid
+    include IgnorableColumn
+    ignore_column :deleted_at
     belongs_to :project
     belongs_to :owner, class_name: "User"

app/models/concerns/internal_id.rb

@@ -10,7 +10,6 @@ module InternalId
     if iid.blank?
       parent = project || group
       records = parent.public_send(self.class.name.tableize) # rubocop:disable GitlabSecurity/PublicSend
-      records = records.with_deleted if self.paranoid?
       max_iid = records.maximum(:iid)
       self.iid = max_iid.to_i + 1

app/models/issue.rb

@@ -12,7 +12,7 @@ class Issue < ActiveRecord::Base
   include ThrottledTouch
   include IgnorableColumn
-  ignore_column :assignee_id, :branch_name
+  ignore_column :assignee_id, :branch_name, :deleted_at
   DueDateStruct = Struct.new(:title, :name).freeze
   NoDueDate     = DueDateStruct.new('No Due Date', '0').freeze
@@ -78,8 +78,6 @@ class Issue < ActiveRecord::Base
     end
   end
-  acts_as_paranoid
-
   class << self
     alias_method :in_parents, :in_projects
   end

app/models/merge_request.rb

@@ -11,7 +11,8 @@ class MergeRequest < ActiveRecord::Base
   include Gitlab::Utils::StrongMemoize
   ignore_column :locked_at,
-                :ref_fetched
+                :ref_fetched,
+                :deleted_at
   belongs_to :target_project, class_name: "Project"
   belongs_to :source_project, class_name: "Project"
@@ -150,8 +151,6 @@ class MergeRequest < ActiveRecord::Base
   after_save :keep_around_commit
-  acts_as_paranoid
-
   def self.reference_prefix
     '!'
   end

app/models/namespace.rb

 class Namespace < ActiveRecord::Base
-  acts_as_paranoid without_default_scope: true
-
   include CacheMarkdownField
   include Sortable
   include Gitlab::ShellAdapter
@@ -10,6 +8,9 @@ class Namespace < ActiveRecord::Base
   include AfterCommitQueue
   include Storage::LegacyNamespace
   include Gitlab::SQL::Pattern
+  include IgnorableColumn
+
+  ignore_column :deleted_at
   # Prevent users from creating unreasonably deep level of nesting.
   # The number 20 was taken based on maximum nesting level of
@@ -221,12 +222,6 @@ class Namespace < ActiveRecord::Base
     has_parent?
   end
-  def soft_delete_without_removing_associations
-    # We can't use paranoia's `#destroy` since this will hard-delete projects.
-    # Project uses `pending_delete` instead of the acts_as_paranoia gem.
-    self.deleted_at = Time.now
-  end
-
   private
   def refresh_access_of_projects_invited_groups

app/serializers/issue_entity.rb

@@ -6,7 +6,6 @@ class IssueEntity < IssuableEntity
   expose :updated_by_id
   expose :created_at
   expose :updated_at
-  expose :deleted_at
   expose :milestone, using: API::Entities::Milestone
   expose :labels, using: LabelEntity
   expose :lock_version

app/services/groups/destroy_service.rb

 module Groups
   class DestroyService < Groups::BaseService
     def async_execute
-      group.soft_delete_without_removing_associations
       job_id = GroupDestroyWorker.perform_async(group.id, current_user.id)
       Rails.logger.info("User #{current_user.id} scheduled a deletion of group ID #{group.id} with job ID #{job_id}")
     end
@@ -23,7 +22,7 @@ module Groups
       group.chat_team&.remove_mattermost_team(current_user)
-      group.really_destroy!
+      group.destroy
     end
   end
 end

app/services/users/destroy_service.rb

@@ -53,7 +53,7 @@ module Users
       # Destroy the namespace after destroying the user since certain methods may depend on the namespace existing
       user_data = user.destroy
-      namespace.really_destroy!
+      namespace.destroy
       user_data
     end

app/workers/group_destroy_worker.rb

@@ -4,7 +4,7 @@ class GroupDestroyWorker
   def perform(group_id, user_id)
     begin
-      group = Group.with_deleted.find(group_id)
+      group = Group.find(group_id)
     rescue ActiveRecord::RecordNotFound
       return
     end

changelogs/unreleased/remove-soft-removals.yml

+---
+title: Remove soft removals related code
+merge_request: 15789
+author:
+type: changed

db/post_migrate/20171207150343_remove_soft_removed_objects.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class RemoveSoftRemovedObjects < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  module SoftRemoved
+    extend ActiveSupport::Concern
+
+    included do
+      scope :soft_removed, -> { where('deleted_at IS NOT NULL') }
+    end
+  end
+
+  class User < ActiveRecord::Base
+    self.table_name = 'users'
+
+    include EachBatch
+  end
+
+  class Issue < ActiveRecord::Base
+    self.table_name = 'issues'
+
+    include EachBatch
+    include SoftRemoved
+  end
+
+  class MergeRequest < ActiveRecord::Base
+    self.table_name = 'merge_requests'
+
+    include EachBatch
+    include SoftRemoved
+  end
+
+  class Namespace < ActiveRecord::Base
+    self.table_name = 'namespaces'
+
+    include EachBatch
+    include SoftRemoved
+
+    scope :soft_removed_personal, -> { soft_removed.where(type: nil) }
+    scope :soft_removed_group, -> { soft_removed.where(type: 'Group') }
+  end
+
+  class Route < ActiveRecord::Base
+    self.table_name = 'routes'
+
+    include EachBatch
+    include SoftRemoved
+  end
+
+  class Project < ActiveRecord::Base
+    self.table_name = 'projects'
+
+    include EachBatch
+    include SoftRemoved
+  end
+
+  class CiPipelineSchedule < ActiveRecord::Base
+    self.table_name = 'ci_pipeline_schedules'
+
+    include EachBatch
+    include SoftRemoved
+  end
+
+  class CiTrigger < ActiveRecord::Base
+    self.table_name = 'ci_triggers'
+
+    include EachBatch
+    include SoftRemoved
+  end
+
+  MODELS = [Issue, MergeRequest, CiPipelineSchedule, CiTrigger].freeze
+
+  def up
+    disable_statement_timeout
+
+    remove_personal_routes
+    remove_personal_namespaces
+    remove_group_namespaces
+    remove_simple_soft_removed_rows
+  end
+
+  def down
+    # The data removed by this migration can't be restored in an automated way.
+  end
+
+  def remove_simple_soft_removed_rows
+    create_temporary_indexes
+
+    MODELS.each do |model|
+      say_with_time("Removing soft removed rows from #{model.table_name}") do
+        model.soft_removed.each_batch do |batch, index|
+          batch.delete_all
+        end
+      end
+    end
+  ensure
+    remove_temporary_indexes
+  end
+
+  def create_temporary_indexes
+    MODELS.each do |model|
+      index_name = temporary_index_name_for(model)
+
+      # Without this index the removal process can take a very long time. For
+      # example, getting the next ID of a batch for the `issues` table in
+      # staging would take between 15 and 20 seconds.
+      next if temporary_index_exists?(model)
+
+      say_with_time("Creating temporary index #{index_name}") do
+        add_concurrent_index(
+          model.table_name,
+          [:deleted_at, :id],
+          name: index_name,
+          where: 'deleted_at IS NOT NULL'
+        )
+      end
+    end
+  end
+
+  def remove_temporary_indexes
+    MODELS.each do |model|
+      index_name = temporary_index_name_for(model)
+
+      next unless temporary_index_exists?(model)
+
+      say_with_time("Removing temporary index #{index_name}") do
+        remove_concurrent_index_by_name(model.table_name, index_name)
+      end
+    end
+  end
+
+  def temporary_index_name_for(model)
+    "index_on_#{model.table_name}_tmp"
+  end
+
+  def temporary_index_exists?(model)
+    index_name = temporary_index_name_for(model)
+
+    index_exists?(model.table_name, [:deleted_at, :id], name: index_name)
+  end
+
+  def remove_personal_namespaces
+    # Some personal namespaces are left behind in case of GitLab.com. In these
+    # cases the associated data such as the projects and users has already been
+    # removed.
+    Namespace.soft_removed_personal.each_batch do |batch|
+      batch.delete_all
+    end
+  end
+
+  def remove_group_namespaces
+    # Left over groups can't be easily removed because we may also need to
+    # remove memberships, repositories, and other associated data. As a result
+    # we'll just schedule a Sidekiq job to remove these.
+    #
+    # As of January 5th, 2018 there are 36 groups that will be removed using
+    # this code.
+    Namespace.select(:id).soft_removed_group.each_batch(of: 10) do |batch, index|
+      # We need the ID of an admin user as the owners of the group may no longer
+      # exist (or might not even be set in `namespaces.owner_id`).
+      admin_id = id_for_admin_user
+
+      batch.each do |ns|
+        schedule_group_removal(index * 5.minutes, ns.id, admin_id)
+      end
+    end
+  end
+
+  def schedule_group_removal(delay, group_id, user_id)
+    if migrate_inline?
+      GroupDestroyWorker.new.perform(group_id, user_id)
+    else
+      GroupDestroyWorker.perform_in(delay, group_id, user_id)
+    end
+  end
+
+  def remove_personal_routes
+    namespaces = Namespace.select(1)
+      .soft_removed
+      .where('namespaces.type IS NULL')
+      .where('routes.source_type = ?', 'Namespace')
+      .where('routes.source_id = namespaces.id')
+
+    Route.where('EXISTS (?)', namespaces).each_batch do |batch|
+      batch.delete_all
+    end
+  end
+
+  def id_for_admin_user
+    return @id_for_admin_user if @id_for_admin_user
+
+    if (admin_id = User.where(admin: true).limit(1).pluck(:id).first)
+      @id_for_admin_user = admin_id
+    else
+      raise 'Can not remove soft removed groups as no admin user exists. ' \
+        'Please make sure at least one user with `admin` set to TRUE exists before proceeding.'
+    end
+  end
+
+  def migrate_inline?
+    Rails.env.test? || Rails.env.development?
+  end
+end

db/post_migrate/20171207150344_remove_deleted_at_columns.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class RemoveDeletedAtColumns < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  TABLES = %i[issues merge_requests namespaces ci_pipeline_schedules ci_triggers].freeze
+  COLUMN = :deleted_at
+
+  def up
+    TABLES.each do |table|
+      remove_column(table, COLUMN) if column_exists?(table, COLUMN)
+    end
+  end
+
+  def down
+    TABLES.each do |table|
+      unless column_exists?(table, COLUMN)
+        add_column(table, COLUMN, :datetime_with_timezone)
+      end
+
+      unless index_exists?(table, COLUMN)
+        add_concurrent_index(table, COLUMN)
+      end
+    end
+  end
+end

db/schema.rb

@@ -356,7 +356,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
     t.integer "project_id"
     t.integer "owner_id"
     t.boolean "active", default: true
-    t.datetime "deleted_at"
     t.datetime "created_at"
     t.datetime "updated_at"
   end
@@ -466,7 +465,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
   create_table "ci_triggers", force: :cascade do |t|
     t.string "token"
-    t.datetime "deleted_at"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer "project_id"
@@ -860,7 +858,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
     t.integer "iid"
     t.integer "updated_by_id"
     t.boolean "confidential", default: false, null: false
-    t.datetime "deleted_at"
     t.date "due_date"
     t.integer "moved_to_id"
     t.integer "lock_version"
@@ -877,7 +874,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
   add_index "issues", ["author_id"], name: "index_issues_on_author_id", using: :btree
   add_index "issues", ["confidential"], name: "index_issues_on_confidential", using: :btree
-  add_index "issues", ["deleted_at"], name: "index_issues_on_deleted_at", using: :btree
   add_index "issues", ["description"], name: "index_issues_on_description_trigram", using: :gin, opclasses: {"description"=>"gin_trgm_ops"}
   add_index "issues", ["milestone_id"], name: "index_issues_on_milestone_id", using: :btree
   add_index "issues", ["moved_to_id"], name: "index_issues_on_moved_to_id", where: "(moved_to_id IS NOT NULL)", using: :btree
@@ -1086,7 +1082,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
     t.boolean "merge_when_pipeline_succeeds", default: false, null: false
     t.integer "merge_user_id"
     t.string "merge_commit_sha"
-    t.datetime "deleted_at"
     t.string "in_progress_merge_commit_sha"
     t.integer "lock_version"
     t.text "title_html"
@@ -1105,7 +1100,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
   add_index "merge_requests", ["assignee_id"], name: "index_merge_requests_on_assignee_id", using: :btree
   add_index "merge_requests", ["author_id"], name: "index_merge_requests_on_author_id", using: :btree
   add_index "merge_requests", ["created_at"], name: "index_merge_requests_on_created_at", using: :btree
-  add_index "merge_requests", ["deleted_at"], name: "index_merge_requests_on_deleted_at", using: :btree
   add_index "merge_requests", ["description"], name: "index_merge_requests_on_description_trigram", using: :gin, opclasses: {"description"=>"gin_trgm_ops"}
   add_index "merge_requests", ["head_pipeline_id"], name: "index_merge_requests_on_head_pipeline_id", using: :btree
   add_index "merge_requests", ["latest_merge_request_diff_id"], name: "index_merge_requests_on_latest_merge_request_diff_id", using: :btree
@@ -1165,7 +1159,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
     t.boolean "share_with_group_lock", default: false
     t.integer "visibility_level", default: 20, null: false
     t.boolean "request_access_enabled", default: false, null: false
-    t.datetime "deleted_at"
     t.text "description_html"
     t.boolean "lfs_enabled"
     t.integer "parent_id"
@@ -1175,7 +1168,6 @@ ActiveRecord::Schema.define(version: 20171230123729) do
   end
   add_index "namespaces", ["created_at"], name: "index_namespaces_on_created_at", using: :btree
-  add_index "namespaces", ["deleted_at"], name: "index_namespaces_on_deleted_at", using: :btree
   add_index "namespaces", ["name", "parent_id"], name: "index_namespaces_on_name_and_parent_id", unique: true, using: :btree
   add_index "namespaces", ["name"], name: "index_namespaces_on_name_trigram", using: :gin, opclasses: {"name"=>"gin_trgm_ops"}
   add_index "namespaces", ["owner_id"], name: "index_namespaces_on_owner_id", using: :btree

doc/api/pipeline_triggers.md

@@ -24,7 +24,6 @@ curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/
         "id": 10,
         "description": "my trigger",
         "created_at": "2016-01-07T09:53:58.235Z",
-        "deleted_at": null,
         "last_used": null,
         "token": "6d056f63e50fe6f8c5f8f4aa10edb7",
         "updated_at": "2016-01-07T09:53:58.235Z",
@@ -55,7 +54,6 @@ curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/
     "id": 10,
     "description": "my trigger",
     "created_at": "2016-01-07T09:53:58.235Z",
-    "deleted_at": null,
     "last_used": null,
     "token": "6d056f63e50fe6f8c5f8f4aa10edb7",
     "updated_at": "2016-01-07T09:53:58.235Z",
@@ -85,7 +83,6 @@ curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --form descri
     "id": 10,
     "description": "my trigger",
     "created_at": "2016-01-07T09:53:58.235Z",
-    "deleted_at": null,
     "last_used": null,
     "token": "6d056f63e50fe6f8c5f8f4aa10edb7",
     "updated_at": "2016-01-07T09:53:58.235Z",
@@ -116,7 +113,6 @@ curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --form descrip
     "id": 10,
     "description": "my trigger",
     "created_at": "2016-01-07T09:53:58.235Z",
-    "deleted_at": null,
     "last_used": null,
     "token": "6d056f63e50fe6f8c5f8f4aa10edb7",
     "updated_at": "2016-01-07T09:53:58.235Z",
@@ -146,7 +142,6 @@ curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitl
     "id": 10,
     "description": "my trigger",
     "created_at": "2016-01-07T09:53:58.235Z",
-    "deleted_at": null,
     "last_used": null,
     "token": "6d056f63e50fe6f8c5f8f4aa10edb7",
     "updated_at": "2016-01-07T09:53:58.235Z",

lib/api/entities.rb

@@ -918,7 +918,7 @@ module API
     class Trigger < Grape::Entity
       expose :id
       expose :token, :description
-      expose :created_at, :updated_at, :deleted_at, :last_used
+      expose :created_at, :updated_at, :last_used
       expose :owner, using: Entities::UserBasic
     end

lib/api/v3/entities.rb

@@ -207,7 +207,7 @@ module API
       end
       class Trigger < Grape::Entity
-        expose :token, :created_at, :updated_at, :deleted_at, :last_used
+        expose :token, :created_at, :updated_at, :last_used
         expose :owner, using: ::API::Entities::UserBasic
       end

lib/gitlab/cycle_analytics/base_query.rb

@@ -15,7 +15,6 @@ module Gitlab
         query = mr_closing_issues_table.join(issue_table).on(issue_table[:id].eq(mr_closing_issues_table[:issue_id]))
           .join(issue_metrics_table).on(issue_table[:id].eq(issue_metrics_table[:issue_id]))
           .where(issue_table[:project_id].eq(@project.id)) # rubocop:disable Gitlab/ModuleWithInstanceVariables
-          .where(issue_table[:deleted_at].eq(nil))
           .where(issue_table[:created_at].gteq(@options[:from])) # rubocop:disable Gitlab/ModuleWithInstanceVariables
         # Load merge_requests