debian-mirror-gitlab/lib/gitlab/database/migrations/background_migration_helpers.rb
2020-08-09 17:44:08 +05:30

157 lines
6.4 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Database
module Migrations
module BackgroundMigrationHelpers
BACKGROUND_MIGRATION_BATCH_SIZE = 1_000 # Number of rows to process per job
BACKGROUND_MIGRATION_JOB_BUFFER_SIZE = 1_000 # Number of jobs to bulk queue at a time
# Bulk queues background migration jobs for an entire table, batched by ID range.
# "Bulk" meaning many jobs will be pushed at a time for efficiency.
# If you need a delay interval per job, then use `queue_background_migration_jobs_by_range_at_intervals`.
#
# model_class - The table being iterated over
# job_class_name - The background migration job class as a string
# batch_size - The maximum number of rows per job
#
# Example:
#
# class Route < ActiveRecord::Base
# include EachBatch
# self.table_name = 'routes'
# end
#
# bulk_queue_background_migration_jobs_by_range(Route, 'ProcessRoutes')
#
# Where the model_class includes EachBatch, and the background migration exists:
#
# class Gitlab::BackgroundMigration::ProcessRoutes
# def perform(start_id, end_id)
# # do something
# end
# end
def bulk_queue_background_migration_jobs_by_range(model_class, job_class_name, batch_size: BACKGROUND_MIGRATION_BATCH_SIZE)
raise "#{model_class} does not have an ID to use for batch ranges" unless model_class.column_names.include?('id')
jobs = []
table_name = model_class.quoted_table_name
model_class.each_batch(of: batch_size) do |relation|
start_id, end_id = relation.pluck("MIN(#{table_name}.id)", "MAX(#{table_name}.id)").first
if jobs.length >= BACKGROUND_MIGRATION_JOB_BUFFER_SIZE
# Note: This code path generally only helps with many millions of rows
# We push multiple jobs at a time to reduce the time spent in
# Sidekiq/Redis operations. We're using this buffer based approach so we
# don't need to run additional queries for every range.
bulk_migrate_async(jobs)
jobs.clear
end
jobs << [job_class_name, [start_id, end_id]]
end
bulk_migrate_async(jobs) unless jobs.empty?
end
# Queues background migration jobs for an entire table, batched by ID range.
# Each job is scheduled with a `delay_interval` in between.
# If you use a small interval, then some jobs may run at the same time.
#
# model_class - The table or relation being iterated over
# job_class_name - The background migration job class as a string
# delay_interval - The duration between each job's scheduled time (must respond to `to_f`)
# batch_size - The maximum number of rows per job
# other_arguments - Other arguments to send to the job
# track_jobs - When this flag is set, creates a record in the background_migration_jobs table for each job that
# is scheduled to be run. These records can be used to trace execution of the background job, but there is no
# builtin support to manage that automatically at this time. You should only set this flag if you are aware of
# how it works, and intend to manually cleanup the database records in your background job.
#
# *Returns the final migration delay*
#
# Example:
#
# class Route < ActiveRecord::Base
# include EachBatch
# self.table_name = 'routes'
# end
#
# queue_background_migration_jobs_by_range_at_intervals(Route, 'ProcessRoutes', 1.minute)
#
# Where the model_class includes EachBatch, and the background migration exists:
#
# class Gitlab::BackgroundMigration::ProcessRoutes
# def perform(start_id, end_id)
# # do something
# end
# end
def queue_background_migration_jobs_by_range_at_intervals(model_class, job_class_name, delay_interval, batch_size: BACKGROUND_MIGRATION_BATCH_SIZE, other_job_arguments: [], initial_delay: 0, track_jobs: false)
raise "#{model_class} does not have an ID to use for batch ranges" unless model_class.column_names.include?('id')
# To not overload the worker too much we enforce a minimum interval both
# when scheduling and performing jobs.
if delay_interval < BackgroundMigrationWorker.minimum_interval
delay_interval = BackgroundMigrationWorker.minimum_interval
end
final_delay = 0
model_class.each_batch(of: batch_size) do |relation, index|
start_id, end_id = relation.pluck(Arel.sql('MIN(id), MAX(id)')).first
# `BackgroundMigrationWorker.bulk_perform_in` schedules all jobs for
# the same time, which is not helpful in most cases where we wish to
# spread the work over time.
final_delay = initial_delay + delay_interval * index
full_job_arguments = [start_id, end_id] + other_job_arguments
track_in_database(job_class_name, full_job_arguments) if track_jobs
migrate_in(final_delay, job_class_name, full_job_arguments)
end
final_delay
end
def perform_background_migration_inline?
Rails.env.test? || Rails.env.development?
end
def migrate_async(*args)
with_migration_context do
BackgroundMigrationWorker.perform_async(*args)
end
end
def migrate_in(*args)
with_migration_context do
BackgroundMigrationWorker.perform_in(*args)
end
end
def bulk_migrate_in(*args)
with_migration_context do
BackgroundMigrationWorker.bulk_perform_in(*args)
end
end
def bulk_migrate_async(*args)
with_migration_context do
BackgroundMigrationWorker.bulk_perform_async(*args)
end
end
def with_migration_context(&block)
Gitlab::ApplicationContext.with_context(caller_id: self.class.to_s, &block)
end
private
def track_in_database(class_name, arguments)
Gitlab::Database::BackgroundMigrationJob.create!(class_name: class_name, arguments: arguments)
end
end
end
end
end