debian-mirror-gitlab/lib/gitlab/database/consistency_checker.rb
2022-07-23 20:15:48 +02:00

122 lines
4.2 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Database
class ConsistencyChecker
BATCH_SIZE = 500
MAX_BATCHES = 20
MAX_RUNTIME = 5.seconds # must be less than the scheduling frequency of the ConsistencyCheck jobs
delegate :monotonic_time, to: :'Gitlab::Metrics::System'
def initialize(source_model:, target_model:, source_columns:, target_columns:)
@source_model = source_model
@target_model = target_model
@source_columns = source_columns
@target_columns = target_columns
@source_sort_column = source_columns.first
@target_sort_column = target_columns.first
@result = { matches: 0, mismatches: 0, batches: 0, mismatches_details: [] }
end
# rubocop:disable Metrics/AbcSize
def execute(start_id:)
current_start_id = start_id
return build_result(next_start_id: nil) if max_id.nil?
return build_result(next_start_id: min_id) if current_start_id > max_id
@start_time = monotonic_time
MAX_BATCHES.times do
if (current_start_id <= max_id) && !over_time_limit?
ids_range = current_start_id...(current_start_id + BATCH_SIZE)
# rubocop: disable CodeReuse/ActiveRecord
source_data = source_model.where(source_sort_column => ids_range)
.order(source_sort_column => :asc).pluck(*source_columns)
target_data = target_model.where(target_sort_column => ids_range)
.order(target_sort_column => :asc).pluck(*target_columns)
# rubocop: enable CodeReuse/ActiveRecord
current_start_id += BATCH_SIZE
result[:matches] += append_mismatches_details(source_data, target_data)
result[:batches] += 1
else
break
end
end
result[:mismatches] = result[:mismatches_details].length
metrics_counter.increment({ source_table: source_model.table_name, result: "match" }, result[:matches])
metrics_counter.increment({ source_table: source_model.table_name, result: "mismatch" }, result[:mismatches])
build_result(next_start_id: current_start_id > max_id ? min_id : current_start_id)
end
# rubocop:enable Metrics/AbcSize
private
attr_reader :source_model, :target_model, :source_columns, :target_columns,
:source_sort_column, :target_sort_column, :start_time, :result
def build_result(next_start_id:)
{ next_start_id: next_start_id }.merge(result)
end
def over_time_limit?
(monotonic_time - start_time) >= MAX_RUNTIME
end
# This where comparing the items happen, and building the diff log
# It returns the number of matching elements
def append_mismatches_details(source_data, target_data)
# Mapping difference the sort key to the item values
# source - target
source_diff_hash = (source_data - target_data).index_by { |item| item.shift }
# target - source
target_diff_hash = (target_data - source_data).index_by { |item| item.shift }
matches = source_data.length - source_diff_hash.length
# Items that exist in the first table + Different items
source_diff_hash.each do |id, values|
result[:mismatches_details] << {
id: id,
source_table: values,
target_table: target_diff_hash[id]
}
end
# Only the items that exist in the target table
target_diff_hash.each do |id, values|
next if source_diff_hash[id] # It's already added
result[:mismatches_details] << {
id: id,
source_table: source_diff_hash[id],
target_table: values
}
end
matches
end
# rubocop: disable CodeReuse/ActiveRecord
def min_id
@min_id ||= source_model.minimum(source_sort_column)
end
def max_id
@max_id ||= source_model.maximum(source_sort_column)
end
# rubocop: enable CodeReuse/ActiveRecord
def metrics_counter
@metrics_counter ||= Gitlab::Metrics.counter(
:consistency_checks,
"Consistency Check Results"
)
end
end
end
end