Fill project_repositories for hashed storage

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Douglas Barbosa Alexandre 2018-12-06 20:46:14 -02:00
parent 5237a55d62
commit 8c9e692095
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3 changed files with 92 additions and 148 deletions

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@ -1,11 +1,11 @@
# frozen_string_literal: true
class BackfillHashedProjectRepositories < ActiveRecord::Migration[5.0]
class BackfillHashedProjectRepositories < ActiveRecord::Migration[4.2]
include Gitlab::Database::MigrationHelpers
DOWNTIME = false
BATCH_SIZE = 1_000
DELAY_INTERVAL = 1.minutes
DELAY_INTERVAL = 5.minutes
MIGRATION = 'BackfillHashedProjectRepositories'
disable_ddl_transaction!
@ -21,7 +21,6 @@ class BackfillHashedProjectRepositories < ActiveRecord::Migration[5.0]
end
def down
# Since there could have been existing rows before the migration
# do not remove anything
# no-op: since there could have been existing rows before the migration do not remove anything
end
end

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@ -2,58 +2,60 @@
module Gitlab
module BackgroundMigration
# Class the will create rows in project_repositories for all
# projects that are on hashed storage
# Class that will create fill the project_repositories table
# for all projects that are on hashed storage and an entry is
# is missing in this table.
class BackfillHashedProjectRepositories
# Model for a Shard
# Shard model
class Shard < ActiveRecord::Base
self.table_name = 'shards'
def self.by_name(name)
to_a.detect { |shard| shard.name == name } || create_by(name: name)
rescue ActiveRecord::RecordNotUnique
retry
end
end
# Class that will find or create the shard by name.
# There is only a small set of shards, which would not change quickly,
# so look them up from memory instead of hitting the DB each time.
# There is only a small set of shards, which would
# not change quickly, so look them up from memory
# instead of hitting the DB each time.
class ShardFinder
def find(name)
shards.detect { |shard| shard.name == name } || create!(name)
def find_shard_id(name)
shard_id = shards.fetch(name, nil)
return shard_id if shard_id.present?
Shard.transaction(requires_new: true) do
create!(name)
end
rescue ActiveRecord::RecordNotUnique
load!
reload!
retry
end
private
def create!(name)
Shard.create!(name: name).tap { |shard| @shards << shard }
Shard.create!(name: name).tap { |shard| @shards[name] = shard.id }
end
def shards
@shards || load!
@shards ||= reload!
end
def load!
@shards = Shard.all.to_a
def reload!
@shards = Hash[*Shard.all.map { |shard| [shard.name, shard.id] }.flatten]
end
end
# Model for a ProjectRepository
# ProjectRegistry model
class ProjectRepository < ActiveRecord::Base
self.table_name = 'project_repositories'
belongs_to :project, inverse_of: :project_repository
end
# Model for a Project
# Project model
class Project < ActiveRecord::Base
self.table_name = 'projects'
HASHED_PATH_PREFIX = '@hashed'
HASHED_STORAGE_FEATURES = {
repository: 1,
attachments: 2
@ -63,33 +65,26 @@ module Gitlab
class << self
def on_hashed_storage
where(arel_table[:storage_version].gteq(HASHED_STORAGE_FEATURES[:repository]))
where(Project.arel_table[:storage_version]
.gteq(HASHED_STORAGE_FEATURES[:repository]))
end
def without_project_repository
cond = ProjectRepository.arel_table[:project_id].eq(nil)
left_outer_joins(:project_repository).where(cond)
joins(left_outer_join_project_repository)
.where(ProjectRepository.arel_table[:project_id].eq(nil))
end
def left_outer_joins(relation)
return super if Gitlab.rails5?
def left_outer_join_project_repository
projects_table = Project.arel_table
repository_table = ProjectRepository.arel_table
# TODO Rails 4?
projects_table
.join(repository_table, Arel::Nodes::OuterJoin)
.on(projects_table[:id].eq(repository_table[:project_id]))
.join_sources
end
end
def project_repository_attributes(shard_finder)
return unless hashed_storage?
{
project_id: id,
shard_id: shard_finder.find(repository_storage).id,
disk_path: hashed_disk_path
}
end
private
def hashed_storage?
self.storage_version && self.storage_version >= 1
end
@ -99,7 +94,7 @@ module Gitlab
end
def disk_hash
@disk_hash ||= Digest::SHA2.hexdigest(id.to_s) if id
@disk_hash ||= Digest::SHA2.hexdigest(id.to_s)
end
end
@ -110,12 +105,27 @@ module Gitlab
private
def project_repositories(start_id, stop_id)
Project.on_hashed_storage.without_project_repository
Project.on_hashed_storage
.without_project_repository
.where(id: start_id..stop_id)
.map { |project| project.project_repository_attributes(shard_finder) }
.map { |project| build_attributes_for_project(project) }
.compact
end
def build_attributes_for_project(project)
return unless project.hashed_storage?
{
project_id: project.id,
shard_id: find_shard_id(project.repository_storage),
disk_path: project.hashed_disk_path
}
end
def find_shard_id(repository_storage)
shard_finder.find_shard_id(repository_storage)
end
def shard_finder
@shard_finder ||= ShardFinder.new
end

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@ -3,59 +3,31 @@
require 'spec_helper'
describe Gitlab::BackgroundMigration::BackfillHashedProjectRepositories, :migration, schema: 20181130102132 do
let(:shards) { table(:shards) }
let(:namespaces) { table(:namespaces) }
let(:projects) { table(:projects) }
let(:project_repositories) { table(:project_repositories) }
let(:projects) { table(:projects) }
let(:shards) { table(:shards) }
let(:group) { namespaces.create!(name: 'foo', path: 'foo') }
let(:default_shard) { shards.create!(name: 'default') }
let(:shard) { shards.create!(name: 'default') }
describe described_class::ShardFinder do
describe '#find' do
subject(:finder) { described_class.new }
it 'creates the shard by name' do
expect(finder).to receive(:create!).and_call_original
expect(finder.find('default')).to be_present
end
it 'does not try to create existing shards' do
shards.create(name: 'default')
expect(finder).not_to receive(:create!)
finder.find('default')
end
it 'only queries the database once for shards' do
finder.find('default')
expect do
finder.find('default')
end.not_to exceed_query_limit(0)
end
describe '#find_shard_id' do
it 'creates a new shard when it does not exist yet' do
expect do
finder.find('other')
end.to change(shards, :count).by(1)
expect { subject.find_shard_id('other') }.to change(shards, :count).by(1)
end
it 'only creates a new shard once' do
finder.find('other')
it 'returns the shard when it exists' do
shards.create(id: 5, name: 'other')
expect do
finder.find('other')
end.not_to change(shards, :count)
shard_id = subject.find_shard_id('other')
expect(shard_id).to eq(5)
end
it 'is not vulnerable to race conditions' do
finder.find('default')
it 'only queries the database once to retrieve shards' do
subject.find_shard_id('default')
other_shard = shards.create(name: 'other')
expect(finder.find('other').id).to eq(other_shard.id)
expect { subject.find_shard_id('default') }.not_to exceed_query_limit(0)
end
end
end
@ -63,93 +35,56 @@ describe Gitlab::BackgroundMigration::BackfillHashedProjectRepositories, :migrat
describe described_class::Project do
describe '.on_hashed_storage' do
it 'finds projects with repository on hashed storage' do
hashed_projects = [
projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1),
projects.create!(name: 'bar', path: 'bar', namespace_id: group.id, storage_version: 2)
]
projects.create!(id: 1, name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1)
projects.create!(id: 2, name: 'bar', path: 'bar', namespace_id: group.id, storage_version: 2)
projects.create!(id: 3, name: 'baz', path: 'baz', namespace_id: group.id, storage_version: 0)
projects.create!(id: 4, name: 'zoo', path: 'zoo', namespace_id: group.id, storage_version: nil)
projects.create!(name: 'baz', path: 'baz', namespace_id: group.id, storage_version: 0)
projects.create!(name: 'quz', path: 'quz', namespace_id: group.id, storage_version: nil)
expect(described_class.on_hashed_storage.pluck(:id)).to match_array(hashed_projects.map(&:id))
expect(described_class.on_hashed_storage.pluck(:id)).to match_array([1, 2])
end
end
describe '.without_project_repository' do
it 'finds projects which do not have a projects_repositories row' do
without_project = projects.create!(name: 'foo', path: 'foo', namespace_id: group.id)
with_project = projects.create!(name: 'bar', path: 'bar', namespace_id: group.id)
project_repositories.create!(project_id: with_project.id, disk_path: '@phony/foo/bar', shard_id: default_shard.id)
it 'finds projects which do not have a projects_repositories entry' do
projects.create!(id: 1, name: 'foo', path: 'foo', namespace_id: group.id)
projects.create!(id: 2, name: 'bar', path: 'bar', namespace_id: group.id)
project_repositories.create!(project_id: 2, disk_path: '@phony/foo/bar', shard_id: shard.id)
expect(described_class.without_project_repository.pluck(:id)).to contain_exactly(without_project.id)
end
end
describe '#project_repository_attributes' do
let(:shard_finder) { Gitlab::BackgroundMigration::BackfillHashedProjectRepositories::ShardFinder.new }
it 'composes the correct attributes for project_repository' do
shiny_shard = shards.create!(name: 'shiny')
project = projects.create!(id: 5, name: 'foo', path: 'foo', namespace_id: group.id, repository_storage: shiny_shard.name, storage_version: 1)
expected_attributes = {
project_id: project.id,
shard_id: shiny_shard.id,
disk_path: '@hashed/ef/2d/ef2d127de37b942baad06145e54b0c619a1f22327b2ebbcfbec78f5564afe39d'
}
expect(described_class.find(project.id).project_repository_attributes(shard_finder)).to eq(expected_attributes)
end
it 'returns nil for a project not on hashed storage' do
project = projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 0)
expect(described_class.find(project.id).project_repository_attributes(shard_finder)).to be_nil
expect(described_class.without_project_repository.pluck(:id)).to contain_exactly(1)
end
end
end
describe '#perform' do
def perform!
described_class.new.perform(1, projects.last.id)
it 'creates a project_repository row for projects on hashed storage that need one' do
projects.create!(id: 1, name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1)
projects.create!(id: 2, name: 'bar', path: 'bar', namespace_id: group.id, storage_version: 2)
expect { described_class.new.perform(1, projects.last.id) }.to change(project_repositories, :count).by(2)
end
it 'create project_repository row for hashed storage project' do
projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1)
it 'does nothing for projects on hashed storage that have already a project_repository row' do
projects.create!(id: 1, name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1)
project_repositories.create!(project_id: 1, disk_path: '@phony/foo/bar', shard_id: shard.id)
expect do
perform!
end.to change(project_repositories, :count).by(1)
end
it 'does nothing for projects that have already a project_repository' do
project = projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1)
project_repositories.create!(project_id: project.id, disk_path: '@phony/foo/bar', shard_id: default_shard.id)
expect do
perform!
end.not_to change(project_repositories, :count)
expect { described_class.new.perform(1, projects.last.id) }.not_to change(project_repositories, :count)
end
it 'does nothing for projects on legacy storage' do
projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 0)
expect do
perform!
end.not_to change(project_repositories, :count)
expect { described_class.new.perform(1, projects.last.id) }.not_to change(project_repositories, :count)
end
it 'inserts rows in a single query' do
projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1, repository_storage: default_shard.name)
projects.create!(name: 'foo', path: 'foo', namespace_id: group.id, storage_version: 1, repository_storage: shard.name)
control_count = ActiveRecord::QueryRecorder.new do
perform!
end
control_count = ActiveRecord::QueryRecorder.new { described_class.new.perform(1, projects.last.id) }
projects.create!(name: 'bar', path: 'bar', namespace_id: group.id, storage_version: 1, repository_storage: default_shard.name)
projects.create!(name: 'quz', path: 'quz', namespace_id: group.id, storage_version: 1, repository_storage: default_shard.name)
projects.create!(name: 'bar', path: 'bar', namespace_id: group.id, storage_version: 1, repository_storage: shard.name)
projects.create!(name: 'zoo', path: 'zoo', namespace_id: group.id, storage_version: 1, repository_storage: shard.name)
expect { perform! }.not_to exceed_query_limit(control_count)
expect { described_class.new.perform(1, projects.last.id) }.not_to exceed_query_limit(control_count)
end
end
end