Finalize conversion to bigint for push_event_payloads

1. Ensure the migration of `event_id` to `event_id_convert_to_bigint` is
completed.
2. Copy indexes and FKs
3. Swap columns

See https://gitlab.com/gitlab-org/gitlab/-/issues/288005.

Changelog: other

db/post_migrate/20210622041846_finalize_push_event_payloads_bigint_conversion.rb

+# frozen_string_literal: true
+
+class FinalizePushEventPayloadsBigintConversion < ActiveRecord::Migration[6.1]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  TABLE_NAME = 'push_event_payloads'
+  INDEX_NAME = 'index_push_event_payloads_on_event_id_convert_to_bigint'
+
+  def up
+    ensure_batched_background_migration_is_finished(
+      job_class_name: 'CopyColumnUsingBackgroundMigrationJob',
+      table_name: 'push_event_payloads',
+      column_name: 'event_id',
+      job_arguments: [["event_id"], ["event_id_convert_to_bigint"]]
+    )
+
+    swap_columns
+  end
+
+  def down
+    swap_columns
+  end
+
+  private
+
+  def swap_columns
+    add_concurrent_index TABLE_NAME, :event_id_convert_to_bigint, unique: true, name: INDEX_NAME
+
+    # Duplicate fk_36c74129da FK
+    add_concurrent_foreign_key TABLE_NAME, :events, column: :event_id_convert_to_bigint, on_delete: :cascade
+
+    with_lock_retries(safe: true) do
+      # Swap column names
+      rename_column TABLE_NAME, :event_id, :event_id_convert_to_bigint_tmp
+      rename_column TABLE_NAME, :event_id_convert_to_bigint, :event_id
+      rename_column TABLE_NAME, :event_id_convert_to_bigint_tmp, :event_id_convert_to_bigint
+
+      # Swap defaults
+      change_column_default TABLE_NAME, :event_id, nil
+      change_column_default TABLE_NAME, :event_id_convert_to_bigint, 0
+
+      # Swap PK constraint
+      execute "ALTER TABLE #{TABLE_NAME} DROP CONSTRAINT push_event_payloads_pkey"
+      rename_index TABLE_NAME, index_name(TABLE_NAME, column: :event_id), 'push_event_payloads_pkey'
+      execute "ALTER TABLE #{TABLE_NAME} ADD CONSTRAINT push_event_payloads_pkey PRIMARY KEY USING INDEX push_event_payloads_pkey"
+
+      # Drop FK fk_36c74129da
+      remove_foreign_key TABLE_NAME, name: concurrent_foreign_key_name(TABLE_NAME, :event_id)
+      # Change the name of the FK for event_id_convert_to_bigint to the FK name for event_id
+      execute <<~SQL
+          ALTER TABLE #{TABLE_NAME}
+          RENAME CONSTRAINT #{concurrent_foreign_key_name(TABLE_NAME, :event_id_convert_to_bigint)}
+          TO #{concurrent_foreign_key_name(TABLE_NAME, :event_id)}
+      SQL
+    end
+  end
+end

db/schema_migrations/20210622041846

+750cda544df323be99452d53aaf39933c8584fc6754ece45263e131884d980d0
\ No newline at end of file

db/structure.sql

@@ -17313,7 +17313,7 @@ ALTER SEQUENCE protected_tags_id_seq OWNED BY protected_tags.id;
 
 CREATE TABLE push_event_payloads (
     commit_count bigint NOT NULL,
-    event_id integer NOT NULL,
+    event_id_convert_to_bigint integer DEFAULT 0 NOT NULL,
     action smallint NOT NULL,
     ref_type smallint NOT NULL,
     commit_from bytea,
@@ -17321,7 +17321,7 @@ CREATE TABLE push_event_payloads (
     ref text,
     commit_title character varying(70),
     ref_count integer,
-    event_id_convert_to_bigint bigint DEFAULT 0 NOT NULL
+    event_id bigint NOT NULL
 );
 
 CREATE TABLE push_rules (

lib/gitlab/database/migration_helpers.rb

@@ -389,12 +389,14 @@ module Gitlab
       # * +logger+ - [Gitlab::JsonLogger]
       # * +env+ - [Hash] custom environment hash, see the example with `DISABLE_LOCK_RETRIES`
       def with_lock_retries(*args, **kwargs, &block)
+        raise_on_exhaustion = !!kwargs.delete(:safe)
         merged_args = {
           klass: self.class,
           logger: Gitlab::BackgroundMigration::Logger
         }.merge(kwargs)
 
-        Gitlab::Database::WithLockRetries.new(**merged_args).run(&block)
+        Gitlab::Database::WithLockRetries.new(**merged_args)
+          .run(raise_on_exhaustion: raise_on_exhaustion, &block)
       end
 
       def true_value

spec/lib/gitlab/database/migration_helpers_spec.rb

@@ -2157,6 +2157,31 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
       buffer.rewind
       expect(buffer.read).to include("\"class\":\"#{model.class}\"")
     end
+
+    using RSpec::Parameterized::TableSyntax
+
+    where(:safe, :raise_on_exhaustion) do
+      true       | true
+      false      | false
+    end
+
+    with_them do
+      it 'sets raise_on_exhaustion as  requested' do
+        with_lock_retries = double
+        expect(Gitlab::Database::WithLockRetries).to receive(:new).and_return(with_lock_retries)
+        expect(with_lock_retries).to receive(:run).with(raise_on_exhaustion: raise_on_exhaustion)
+
+        model.with_lock_retries(env: env, logger: in_memory_logger, safe: safe) { }
+      end
+    end
+
+    it 'does not raise on exhaustion by default' do
+      with_lock_retries = double
+      expect(Gitlab::Database::WithLockRetries).to receive(:new).and_return(with_lock_retries)
+      expect(with_lock_retries).to receive(:run).with(raise_on_exhaustion: false)
+
+      model.with_lock_retries(env: env, logger: in_memory_logger) { }
+    end
   end
 
   describe '#backfill_iids' do