gitlab-org--gitlab-foss/rubocop/cop/migration/update_large_table.rb
Sean McGivern 03ccd39a0c Add more large tables to cop
These are all over 20 GB on GitLab.com. merge_request_diff_commits is several
hundred gigabytes in size.
2018-06-22 12:08:39 +01:00

68 lines
1.9 KiB
Ruby

require_relative '../../migration_helpers'
module RuboCop
module Cop
module Migration
# This cop checks for `add_column_with_default` on a table that's been
# explicitly blacklisted because of its size.
#
# Even though this helper performs the update in batches to avoid
# downtime, using it with tables with millions of rows still causes a
# significant delay in the deploy process and is best avoided.
#
# See https://gitlab.com/gitlab-com/infrastructure/issues/1602 for more
# information.
class UpdateLargeTable < RuboCop::Cop::Cop
include MigrationHelpers
MSG = 'Using `%s` on the `%s` table will take a long time to ' \
'complete, and should be avoided unless absolutely ' \
'necessary'.freeze
LARGE_TABLES = %i[
ci_build_trace_sections
ci_builds
ci_job_artifacts
ci_pipelines
ci_stages
events
issues
merge_request_diff_commits
merge_request_diff_files
merge_request_diffs
merge_requests
namespaces
notes
projects
routes
users
].freeze
BATCH_UPDATE_METHODS = %w[
:add_column_with_default
:change_column_type_concurrently
:rename_column_concurrently
:update_column_in_batches
].join(' ').freeze
def_node_matcher :batch_update?, <<~PATTERN
(send nil? ${#{BATCH_UPDATE_METHODS}} $(sym ...) ...)
PATTERN
def on_send(node)
return unless in_migration?(node)
matches = batch_update?(node)
return unless matches
update_method = matches.first
table = matches.last.to_a.first
return unless LARGE_TABLES.include?(table)
add_offense(node, location: :expression, message: format(MSG, update_method, table))
end
end
end
end
end