debian-mirror-gitlab/lib/gitlab/database/migrations/timeout_helpers.rb
2023-01-12 18:35:48 +00:00

61 lines
2.2 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Database
module Migrations
module TimeoutHelpers
# Long-running migrations may take more than the timeout allowed by
# the database. Disable the session's statement timeout to ensure
# migrations don't get killed prematurely.
#
# There are two possible ways to disable the statement timeout:
#
# - Per transaction (this is the preferred and default mode)
# - Per connection (requires a cleanup after the execution)
#
# When using a per connection disable statement, code must be inside
# a block so we can automatically execute `RESET statement_timeout` after block finishes
# otherwise the statement will still be disabled until connection is dropped
# or `RESET statement_timeout` is executed
def disable_statement_timeout
if block_given?
if statement_timeout_disabled?
# Don't do anything if the statement_timeout is already disabled
# Allows for nested calls of disable_statement_timeout without
# resetting the timeout too early (before the outer call ends)
yield
else
begin
execute('SET statement_timeout TO 0')
yield
ensure
execute('RESET statement_timeout')
end
end
else
unless transaction_open?
raise <<~ERROR
Cannot call disable_statement_timeout() without a transaction open or outside of a transaction block.
If you don't want to use a transaction wrap your code in a block call:
disable_statement_timeout { # code that requires disabled statement here }
This will make sure statement_timeout is disabled before and reset after the block execution is finished.
ERROR
end
execute('SET LOCAL statement_timeout TO 0')
end
end
private
def statement_timeout_disabled?
# This is a string of the form "100ms" or "0" when disabled
connection.select_value('SHOW statement_timeout') == "0"
end
end
end
end
end