Create module for reindexing

This introduces a namespace for the reindexing code

lib/gitlab/database/concurrent_reindex.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Database
-    class ConcurrentReindex
-      include Gitlab::Utils::StrongMemoize
-      include MigrationHelpers
-
-      ReindexError = Class.new(StandardError)
-
-      PG_IDENTIFIER_LENGTH = 63
-      TEMPORARY_INDEX_PREFIX = 'tmp_reindex_'
-      REPLACED_INDEX_PREFIX = 'old_reindex_'
-
-      attr_reader :index_name, :logger
-
-      def initialize(index_name, logger:)
-        @index_name = index_name
-        @logger = logger
-      end
-
-      def perform
-        raise ReindexError, "index #{index_name} does not exist" unless index_exists?
-
-        raise ReindexError, 'UNIQUE indexes are currently not supported' if index_unique?
-
-        logger.debug("dropping dangling index from previous run: #{replacement_index_name}")
-        remove_replacement_index
-
-        begin
-          create_replacement_index
-
-          unless replacement_index_valid?
-            message = 'replacement index was created as INVALID'
-            logger.error("#{message}, cleaning up")
-            raise ReindexError, "failed to reindex #{index_name}: #{message}"
-          end
-
-          swap_replacement_index
-        rescue Gitlab::Database::WithLockRetries::AttemptsExhaustedError => e
-          logger.error('failed to obtain the required database locks to swap the indexes, cleaning up')
-          raise ReindexError, e.message
-        rescue ActiveRecord::ActiveRecordError, PG::Error => e
-          logger.error("database error while attempting reindex of #{index_name}: #{e.message}")
-          raise ReindexError, e.message
-        ensure
-          logger.info("dropping unneeded replacement index: #{replacement_index_name}")
-          remove_replacement_index
-        end
-      end
-
-      private
-
-      delegate :execute, to: :connection
-      def connection
-        @connection ||= ActiveRecord::Base.connection
-      end
-
-      def replacement_index_name
-        @replacement_index_name ||= constrained_index_name(TEMPORARY_INDEX_PREFIX)
-      end
-
-      def index
-        strong_memoize(:index) do
-          find_index(index_name)
-        end
-      end
-
-      def index_exists?
-        !index.nil?
-      end
-
-      def index_unique?
-        index.indisunique
-      end
-
-      def constrained_index_name(prefix)
-        "#{prefix}#{index_name}".slice(0, PG_IDENTIFIER_LENGTH)
-      end
-
-      def create_replacement_index
-        create_replacement_index_statement = index.indexdef
-          .sub(/CREATE INDEX/, 'CREATE INDEX CONCURRENTLY')
-          .sub(/#{index_name}/, replacement_index_name)
-
-        logger.info("creating replacement index #{replacement_index_name}")
-        logger.debug("replacement index definition: #{create_replacement_index_statement}")
-
-        disable_statement_timeout do
-          connection.execute(create_replacement_index_statement)
-        end
-      end
-
-      def replacement_index_valid?
-        find_index(replacement_index_name).indisvalid
-      end
-
-      def find_index(index_name)
-        record = connection.select_one(<<~SQL)
-          SELECT
-            pg_index.indisunique,
-            pg_index.indisvalid,
-            pg_indexes.indexdef
-          FROM pg_index
-          INNER JOIN pg_class ON pg_class.oid = pg_index.indexrelid
-          INNER JOIN pg_namespace ON pg_class.relnamespace = pg_namespace.oid
-          INNER JOIN pg_indexes ON pg_class.relname = pg_indexes.indexname
-          WHERE pg_namespace.nspname = 'public'
-          AND pg_class.relname = #{connection.quote(index_name)}
-        SQL
-
-        OpenStruct.new(record) if record
-      end
-
-      def swap_replacement_index
-        replaced_index_name = constrained_index_name(REPLACED_INDEX_PREFIX)
-
-        logger.info("swapping replacement index #{replacement_index_name} with #{index_name}")
-
-        with_lock_retries do
-          rename_index(index_name, replaced_index_name)
-          rename_index(replacement_index_name, index_name)
-          rename_index(replaced_index_name, replacement_index_name)
-        end
-      end
-
-      def rename_index(old_index_name, new_index_name)
-        connection.execute("ALTER INDEX #{old_index_name} RENAME TO #{new_index_name}")
-      end
-
-      def remove_replacement_index
-        disable_statement_timeout do
-          connection.execute("DROP INDEX CONCURRENTLY IF EXISTS #{replacement_index_name}")
-        end
-      end
-
-      def with_lock_retries(&block)
-        arguments = { klass: self.class, logger: logger }
-
-        Gitlab::Database::WithLockRetries.new(arguments).run(raise_on_exhaustion: true, &block)
-      end
-    end
-  end
-end

lib/gitlab/database/reindexing/concurrent_reindex.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module Reindexing
+      class ConcurrentReindex
+        include Gitlab::Utils::StrongMemoize
+        include MigrationHelpers
+
+        ReindexError = Class.new(StandardError)
+
+        PG_IDENTIFIER_LENGTH = 63
+        TEMPORARY_INDEX_PREFIX = 'tmp_reindex_'
+        REPLACED_INDEX_PREFIX = 'old_reindex_'
+
+        attr_reader :index, :logger
+
+        def initialize(index, logger: Gitlab::AppLogger)
+          @index = index
+          @logger = logger
+        end
+
+        def perform
+          raise ReindexError, 'UNIQUE indexes are currently not supported' if index.unique?
+
+          with_rebuilt_index do |replacement_index|
+            swap_index(replacement_index)
+          end
+        end
+
+        private
+
+        def with_rebuilt_index
+          logger.debug("dropping dangling index from previous run (if it exists): #{replacement_index_name}")
+          remove_replacement_index
+
+          create_replacement_index_statement = index.definition
+            .sub(/CREATE INDEX/, 'CREATE INDEX CONCURRENTLY')
+            .sub(/#{index.name}/, replacement_index_name)
+
+          logger.info("creating replacement index #{replacement_index_name}")
+          logger.debug("replacement index definition: #{create_replacement_index_statement}")
+
+          disable_statement_timeout do
+            connection.execute(create_replacement_index_statement)
+          end
+
+          replacement_index = Index.find_with_schema("#{index.schema}.#{replacement_index_name}")
+
+          unless replacement_index.valid?
+            message = 'replacement index was created as INVALID'
+            logger.error("#{message}, cleaning up")
+            raise ReindexError, "failed to reindex #{index}: #{message}"
+          end
+
+          yield replacement_index
+
+        rescue Gitlab::Database::WithLockRetries::AttemptsExhaustedError => e
+          logger.error('failed to obtain the required database locks to swap the indexes, cleaning up')
+          raise ReindexError, e.message
+        rescue ActiveRecord::ActiveRecordError, PG::Error => e
+          logger.error("database error while attempting reindex of #{index}: #{e.message}")
+          raise ReindexError, e.message
+        ensure
+          logger.info("dropping unneeded replacement index: #{replacement_index_name}")
+          remove_replacement_index
+        end
+
+        def swap_index(replacement_index)
+          replaced_index_name = constrained_index_name(REPLACED_INDEX_PREFIX)
+
+          logger.info("swapping replacement index #{replacement_index} with #{index}")
+
+          with_lock_retries do
+            rename_index(index.name, replaced_index_name)
+            rename_index(replacement_index.name, index.name)
+            rename_index(replaced_index_name, replacement_index.name)
+          end
+        end
+
+        def rename_index(old_index_name, new_index_name)
+          connection.execute("ALTER INDEX #{old_index_name} RENAME TO #{new_index_name}")
+        end
+
+        def remove_replacement_index
+          disable_statement_timeout do
+            connection.execute("DROP INDEX CONCURRENTLY IF EXISTS #{replacement_index_name}")
+          end
+        end
+
+        def replacement_index_name
+          @replacement_index_name ||= constrained_index_name(TEMPORARY_INDEX_PREFIX)
+        end
+
+        def constrained_index_name(prefix)
+          "#{prefix}#{index.name}".slice(0, PG_IDENTIFIER_LENGTH)
+        end
+
+        def with_lock_retries(&block)
+          arguments = { klass: self.class, logger: logger }
+
+          Gitlab::Database::WithLockRetries.new(arguments).run(raise_on_exhaustion: true, &block)
+        end
+
+        delegate :execute, to: :connection
+        def connection
+          @connection ||= ActiveRecord::Base.connection
+        end
+      end
+    end
+  end
+end

lib/gitlab/database/reindexing/index.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module Reindexing
+      class Index
+        def self.find_with_schema(full_name)
+          raise ArgumentError, "Index name is not fully qualified with a schema: #{full_name}" unless full_name =~ /^\w+\.\w+$/
+
+          schema, index = full_name.split('.')
+
+          record = ActiveRecord::Base.connection.select_one(<<~SQL)
+            SELECT
+              pg_index.indisunique as is_unique,
+              pg_index.indisvalid as is_valid,
+              pg_indexes.indexdef as definition,
+              pg_namespace.nspname as schema,
+              pg_class.relname as name
+            FROM pg_index
+            INNER JOIN pg_class ON pg_class.oid = pg_index.indexrelid
+            INNER JOIN pg_namespace ON pg_class.relnamespace = pg_namespace.oid
+            INNER JOIN pg_indexes ON pg_class.relname = pg_indexes.indexname
+            WHERE pg_namespace.nspname = #{ActiveRecord::Base.connection.quote(schema)}
+            AND pg_class.relname = #{ActiveRecord::Base.connection.quote(index)}
+          SQL
+
+          return unless record
+
+          new(OpenStruct.new(record))
+        end
+
+        delegate :definition, :schema, :name, to: :@attrs
+
+        def initialize(attrs)
+          @attrs = attrs
+        end
+
+        def unique?
+          @attrs.is_unique
+        end
+
+        def valid?
+          @attrs.is_valid
+        end
+
+        def to_s
+          name
+        end
+      end
+    end
+  end
+end

lib/tasks/gitlab/db.rake

@@ -170,13 +170,18 @@ namespace :gitlab do
     desc 'reindex a regular (non-unique) index without downtime to eliminate bloat'
     task :reindex, [:index_name] => :environment do |_, args|
       unless Feature.enabled?(:database_reindexing, type: :ops)
-        puts "This feature (database_reindexing) is currently disabled.".yellow
+        puts "This feature (database_reindexing) is currently disabled.".color(:yellow)
         exit
       end
 
       raise ArgumentError, 'must give the index name to reindex' unless args[:index_name]
 
-      Gitlab::Database::ConcurrentReindex.new(args[:index_name], logger: Logger.new(STDOUT)).perform
+      index = Gitlab::Database::Reindexing::Index.find_with_schema(args[:index_name])
+
+      raise ArgumentError, "Given index does not exist: #{args[:index_name]}" unless index
+
+      puts "Rebuilding index #{index}".color(:green)
+      Gitlab::Database::Reindexing::ConcurrentReindex.new(index).perform
     end
   end
 end

spec/lib/gitlab/database/concurrent_reindex_spec.rb → spec/lib/gitlab/database/reindexing/concurrent_reindex_spec.rb

@@ -2,12 +2,13 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
-  subject { described_class.new(index_name, logger: logger) }
+RSpec.describe Gitlab::Database::Reindexing::ConcurrentReindex, '#perform' do
+  subject { described_class.new(index, logger: logger) }
 
   let(:table_name) { '_test_reindex_table' }
   let(:column_name) { '_test_column' }
   let(:index_name) { '_test_reindex_index' }
+  let(:index) { double('index', name: index_name, schema: 'public', unique?: false, definition: 'CREATE INDEX _test_reindex_index ON public._test_reindex_table USING btree (_test_column)') }
   let(:logger) { double('logger', debug: nil, info: nil, error: nil ) }
   let(:connection) { ActiveRecord::Base.connection }
 
@@ -17,29 +18,12 @@ RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
         id serial NOT NULL PRIMARY KEY,
         #{column_name} integer NOT NULL);
 
-      CREATE INDEX #{index_name} ON #{table_name} (#{column_name});
+      CREATE INDEX #{index.name} ON #{table_name} (#{column_name});
     SQL
   end
 
-  context 'when the index does not exist' do
-    before do
-      connection.execute(<<~SQL)
-        DROP INDEX #{index_name}
-      SQL
-    end
-
-    it 'raises an error' do
-      expect { subject.perform }.to raise_error(described_class::ReindexError, /does not exist/)
-    end
-  end
-
   context 'when the index is unique' do
-    before do
-      connection.execute(<<~SQL)
-        DROP INDEX #{index_name};
-        CREATE UNIQUE INDEX #{index_name} ON #{table_name} (#{column_name})
-      SQL
-    end
+    let(:index) { double('index', name: index_name, unique?: true, definition: 'CREATE INDEX _test_reindex_index ON public._test_reindex_table USING btree (_test_column)') }
 
     it 'raises an error' do
       expect do
@@ -83,8 +67,8 @@ RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
           expect(instance).to receive(:run).with(raise_on_exhaustion: true).and_yield
         end
 
-        expect_to_execute_in_order("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
-        expect_to_execute_in_order("ALTER INDEX #{replacement_name} RENAME TO #{index_name}")
+        expect_to_execute_in_order("ALTER INDEX #{index.name} RENAME TO #{replaced_name}")
+        expect_to_execute_in_order("ALTER INDEX #{replacement_name} RENAME TO #{index.name}")
         expect_to_execute_in_order("ALTER INDEX #{replaced_name} RENAME TO #{replacement_name}")
 
         expect_to_execute_concurrently_in_order(drop_index)
@@ -109,8 +93,8 @@ RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
             expect(instance).to receive(:run).with(raise_on_exhaustion: true).and_yield
           end
 
-          expect_to_execute_in_order("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
-          expect_to_execute_in_order("ALTER INDEX #{replacement_name} RENAME TO #{index_name}")
+          expect_to_execute_in_order("ALTER INDEX #{index.name} RENAME TO #{replaced_name}")
+          expect_to_execute_in_order("ALTER INDEX #{replacement_name} RENAME TO #{index.name}")
           expect_to_execute_in_order("ALTER INDEX #{replaced_name} RENAME TO #{replacement_name}")
 
           expect_to_execute_concurrently_in_order(drop_index)
@@ -141,7 +125,8 @@ RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
           expect_to_execute_concurrently_in_order(drop_index)
           expect_to_execute_concurrently_in_order(create_index)
 
-          expect(subject).to receive(:replacement_index_valid?).and_return(false)
+          replacement_index = double('replacement index', valid?: false)
+          allow(Gitlab::Database::Reindexing::Index).to receive(:find_with_schema).with("public.#{replacement_name}").and_return(replacement_index)
 
           expect_to_execute_concurrently_in_order(drop_index)
 
@@ -161,8 +146,8 @@ RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
           end
 
           expect(connection).to receive(:execute).ordered
-            .with("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
-            .and_raise(ActiveRecord::ConnectionTimeoutError, 'connect timeout')
+          .with("ALTER INDEX #{index.name} RENAME TO #{replaced_name}")
+          .and_raise(ActiveRecord::ConnectionTimeoutError, 'connect timeout')
 
           expect_to_execute_concurrently_in_order(drop_index)
 
@@ -209,7 +194,7 @@ RSpec.describe Gitlab::Database::ConcurrentReindex, '#perform' do
       SELECT indexdef
       FROM pg_indexes
       WHERE schemaname = 'public'
-      AND indexname = #{ActiveRecord::Base.connection.quote(index_name)}
+      AND indexname = #{ActiveRecord::Base.connection.quote(index.name)}
     SQL
   end
 

spec/lib/gitlab/database/reindexing/index_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Database::Reindexing::Index do
+  before do
+    ActiveRecord::Base.connection.execute(<<~SQL)
+      CREATE INDEX foo_idx ON public.users (name);
+      CREATE UNIQUE INDEX bar_key ON public.users (id);
+
+      CREATE TABLE example_table (id serial primary key);
+    SQL
+  end
+
+  def find(name)
+    described_class.find_with_schema(name)
+  end
+
+  describe '.find_with_schema' do
+    it 'returns an instance of Gitlab::Database::Reindexing::Index when the index is present' do
+      expect(find('public.foo_idx')).to be_a(Gitlab::Database::Reindexing::Index)
+    end
+
+    it 'returns nil if the index is not present' do
+      expect(find('public.idontexist')).to be_nil
+    end
+
+    it 'raises ArgumentError if given a non-fully qualified index name' do
+      expect { find('foo') }.to raise_error(ArgumentError, /not fully qualified/)
+    end
+  end
+
+  describe '#unique?' do
+    it 'returns true for a unique index' do
+      expect(find('public.bar_key')).to be_unique
+    end
+
+    it 'returns false for a regular, non-unique index' do
+      expect(find('public.foo_idx')).not_to be_unique
+    end
+
+    it 'returns true for a primary key index' do
+      expect(find('public.example_table_pkey')).to be_unique
+    end
+  end
+
+  describe '#valid?' do
+    it 'returns true if the index is valid' do
+      expect(find('public.foo_idx')).to be_valid
+    end
+
+    it 'returns false if the index is marked as invalid' do
+      ActiveRecord::Base.connection.execute(<<~SQL)
+        UPDATE pg_index SET indisvalid=false
+        FROM pg_class
+        WHERE pg_class.relname = 'foo_idx' AND pg_index.indexrelid = pg_class.oid
+      SQL
+
+      expect(find('public.foo_idx')).not_to be_valid
+    end
+  end
+
+  describe '#to_s' do
+    it 'returns the index name' do
+      expect(find('public.foo_idx').to_s).to eq('foo_idx')
+    end
+  end
+
+  describe '#name' do
+    it 'returns the name' do
+      expect(find('public.foo_idx').name).to eq('foo_idx')
+    end
+  end
+
+  describe '#schema' do
+    it 'returns the index schema' do
+      expect(find('public.foo_idx').schema).to eq('public')
+    end
+  end
+
+  describe '#definition' do
+    it 'returns the index definition' do
+      expect(find('public.foo_idx').definition).to eq('CREATE INDEX foo_idx ON public.users USING btree (name)')
+    end
+  end
+end

spec/tasks/gitlab/db_rake_spec.rb

@@ -173,16 +173,23 @@ RSpec.describe 'gitlab:db namespace rake task' do
       end
     end
 
-    it 'calls the index rebuilder with the proper arguments' do
-      reindex = double('rebuilder')
+    context 'with index name given' do
+      let(:index) { double('index') }
+      let(:reindex) { double('reindex') }
 
-      expect(Gitlab::Database::ConcurrentReindex).to receive(:new)
-        .with('some_index_name', logger: instance_of(Logger))
-        .and_return(reindex)
+      it 'calls the index rebuilder with the proper arguments' do
+        expect(Gitlab::Database::Reindexing::Index).to receive(:find_with_schema).with('public.foo_idx').and_return(index)
+        expect(Gitlab::Database::Reindexing::ConcurrentReindex).to receive(:new).with(index, any_args).and_return(reindex)
+        expect(reindex).to receive(:perform)
 
-      expect(reindex).to receive(:perform)
+        run_rake_task('gitlab:db:reindex', '[public.foo_idx]')
+      end
+
+      it 'raises an error if the index does not exist' do
+        expect(Gitlab::Database::Reindexing::Index).to receive(:find_with_schema).with('public.absent_index').and_return(nil)
 
-      run_rake_task('gitlab:db:reindex', '[some_index_name]')
+        expect { run_rake_task('gitlab:db:reindex', '[public.absent_index]') }.to raise_error(ArgumentError, /index does not exist/)
+      end
     end
   end