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# frozen_string_literal: true
require 'spec_helper'
RSpec.describe Gitlab::Database::ConcurrentReindex, '#execute' do
subject { described_class.new(index_name, logger: logger) }
let(:table_name) { '_test_reindex_table' }
let(:column_name) { '_test_column' }
let(:index_name) { '_test_reindex_index' }
let(:logger) { double('logger', debug: nil, info: nil, error: nil ) }
let(:connection) { ActiveRecord::Base.connection }
before do
connection.execute(<<~SQL)
CREATE TABLE #{table_name} (
id serial NOT NULL PRIMARY KEY,
#{column_name} integer NOT NULL);
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.execute }.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
it 'raises an error' do
expect do
subject.execute
end.to raise_error(described_class::ReindexError, /UNIQUE indexes are currently not supported/)
end
end
context 'replacing the original index with a rebuilt copy' do
let(:replacement_name) { 'tmp_reindex__test_reindex_index' }
let(:replaced_name) { 'old_reindex__test_reindex_index' }
let(:create_index) { "CREATE INDEX CONCURRENTLY #{replacement_name} ON public.#{table_name} USING btree (#{column_name})" }
let(:drop_index) { "DROP INDEX CONCURRENTLY IF EXISTS #{replacement_name}" }
let!(:original_index) { find_index_create_statement }
before do
allow(subject).to receive(:connection).and_return(connection)
allow(subject).to receive(:disable_statement_timeout).and_yield
end
it 'replaces the existing index with an identical index' do
expect(subject).to receive(:disable_statement_timeout).exactly(3).times.and_yield
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
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 #{replaced_name} RENAME TO #{replacement_name}")
expect_to_execute_concurrently_in_order(drop_index)
subject.execute
check_index_exists
end
context 'when a dangling index is left from a previous run' do
before do
connection.execute("CREATE INDEX #{replacement_name} ON #{table_name} (#{column_name})")
end
it 'replaces the existing index with an identical index' do
expect(subject).to receive(:disable_statement_timeout).exactly(3).times.and_yield
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
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 #{replaced_name} RENAME TO #{replacement_name}")
expect_to_execute_concurrently_in_order(drop_index)
subject.execute
check_index_exists
end
end
context 'when it fails to create the replacement index' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect(connection).to receive(:execute).with(create_index).ordered
.and_raise(ActiveRecord::ConnectionTimeoutError, 'connect timeout')
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /connect timeout/)
check_index_exists
end
end
context 'when the replacement index is not valid' do
it 'safely cleans up and signals the error' 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)
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /replacement index was created as INVALID/)
check_index_exists
end
end
context 'when a database error occurs while swapping the indexes' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
expect(instance).to receive(:run).with(raise_on_exhaustion: true).and_yield
end
expect(connection).to receive(:execute).ordered
.with("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
.and_raise(ActiveRecord::ConnectionTimeoutError, 'connect timeout')
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /connect timeout/)
check_index_exists
end
end
context 'when with_lock_retries fails to acquire the lock' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
expect(instance).to receive(:run).with(raise_on_exhaustion: true)
.and_raise(::Gitlab::Database::WithLockRetries::AttemptsExhaustedError, 'exhausted')
end
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /exhausted/)
check_index_exists
end
end
end
def expect_to_execute_concurrently_in_order(sql)
# Indexes cannot be created CONCURRENTLY in a transaction. Since the tests are wrapped in transactions,
# verify the original call but pass through the non-concurrent form.
expect(connection).to receive(:execute).with(sql).ordered.and_wrap_original do |method, sql|
method.call(sql.sub(/CONCURRENTLY/, ''))
end
end
def expect_to_execute_in_order(sql)
expect(connection).to receive(:execute).with(sql).ordered.and_call_original
end
def find_index_create_statement
ActiveRecord::Base.connection.select_value(<<~SQL)
SELECT indexdef
FROM pg_indexes
WHERE schemaname = 'public'
AND indexname = #{ActiveRecord::Base.connection.quote(index_name)}
SQL
end
def check_index_exists
expect(find_index_create_statement).to eq(original_index)
end
end
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